Support fo Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org.

Also by the Consumers Energy Foundation dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available a ConsumersEnergy.com/foundation.

And by viewers like you.

Thank you.

Hi, I'm Rob Stevenson and this is Curious Crew!

Welcome to the show, everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulate curiosity.

That's exactly right.

And I've got some fun plans for you today.

And in fact, we're going to start with somethin called the Cruising Crew Trials.

And this is going to involve this long stretchy band, a skateboard and a special app on my phone.

That is an accelerometer.

Now, one of you is going to get moving, and I think we're going to start with Lake.

Let's get set up.

Okay.

So we've got Lake set up here.

And AvaGail, Emmanuel, thank you so much.

They're going to be supplying some tension on this band, trying to hold that really steady.

Now, Nicholas, Annlyn, can you do me a favor?

In just a moment I'm going to have you pull Lake back all the way to this blue mark on the floor and on the count of three, we're going to let her go.

And lake you're going to start that app.

Ready?

Let's pull her back.

Okay.

Pulling her all the way back to the blue mark.

AvaGail, Emmanuel, hold it tight.

Let's count it down, everybody.

Three, two, one, go.

Nice job.

There she goes.

Good bye, Lake.

Excellent job.

You can hit pause on the accelerometer.

I'm going to be really interested to see what that looks like.

You know what?

I think it's time to launch someone else.

Leon.

We're going to get him ready.

Okay.

Leon's ready for the second trial.

Let's pull him back all the way to the blue mark again and help me count down.

Three, two, one, Go.

There he goes!

Goodbye Leon!

Go ahead and hit pause on that accelerometer.

Great job, Leon.

I think I'm ready for one more.

And it's going to be Eyad, we're going to get him ready next!

Okay, Eyad's ready, so let' pull him back to the blue mark and we're going to count it down.

Three, two, one, go.

There he goes.

Goodbye Eyad!

And you can hit the pause.

Now, surprisingly, I' going to do Eyad one more time.

What?

You'll see why.

So the last trial, Eyad's ready.

But this time when you pull him back, only pull him to the green mark.

Let's try it right there.

And three, two, one, Go.

Oh, that was so disappointing.

Now that's where it gets interesting.

We're going to have to talk about this.

Let's clea this up and do a little debrief so some of you look pretty good cruising on that skateboard and we made some interesting observations.

Right.

I'm going to ask three of you to really think about those observations to see if you can come up with some scientific modeling and explain them by the end of the show, you can use your background knowledge, evidence that you learn, who would like to d a little modeling moment today?

Okay.

Emmanuel.

Julia, AvaGail, you three.

Now, does anybody have a guess what we're going to be investigating today?

You really have a guess?

What is your guess Lake?

Momentum.

Momentum?

I love that with such confidence.

That is actually a part of what we're going to be investigating.

We are going to explore Newton's second law of motion.

Stick around.

It's going to be full speed ahead.

Let' see if we can figure this out.

I've never seen an accelerometer before.

It was cool how it detected the movement of the car.t I know we could definitely tell that like accelerated faster than Leon.

And Eyad's first ride, there is more acceleration.

The input force definitely makes a difference in an object's acceleration.

Sir Isaac Newton was an English physicist and mathematicia who explained the relationship between forces on an object and the object's motion.

In 1687, he published his Laws of Motion in the Principia Mathematica.

His second law of motio describes how the acceleration of an objec depends on both force and mass.

When you ride your bike, you can accelerate by pushing on the pedals, and if you apply more force on the pedals, you can go even faster.

See you later.

So you both did a really good job riding those skateboards.

Maybe next time, okay Nicholas?

Sorry about that.

But we do need to try to make sense of Newton's second law of motion.

And I want to start with these two spheres right here.

What do you notice about these two, Lake?

One thing is they're not even moving.

Okay, so we're talking about motion, and they're not in motion.

That is a super great observation.

And in fact, they are experiencing forces, though there's a force of gravity and there's actually a force called the normal force, which is pushing up.

And if they're balanced, things stay still.

But what can we do Lake to try to get this first rubber ball to move?

Well, we can maybe touch it or touch it, mov it a little, Push it a little.

Okay.

I've got a really crazy idea.

We're going to try something.

This'll be fun.

I have a little foam dart that I'm going to launch at this bal to see if we can get it to move.

Now, I also want to try something, though, righ before we launch it, Lake, I'm going to ask you to put your hand behind it right up against the ball, because I want to ask you a question about that.

But safety first, everybody let's get some goggles on here.

We don't want any stra pieces of foam headed our way.

Okay.

So we've got this ready, Lake, go ahead and put your hand behind it and we're going to launch it.

Let's see what happens.

Oh my gosh!

It went flying over there.

Okay.

So could you feel the force?

I could feel a little... boop!

You could feel that, couldn't you?

So we try it one more time.

This time, I'm not going to have you stop it.

You ready?

Oh, so it's sort of moved around and hit the other ball, didn't it?

Oh, yeah.

The other ball stopped it.

Oh, interesting.

Okay, now that other bal is kind of an interesting one.

That is a bowling ball.

A 16 lb bowling ball.

Eyad, do you think we're going to be able to move it with this little dart?

What do you think?

Absolutely not.

He says with confidence.

Absolutely not.

I think you are right!

Okay.

Take that off.

How come we couldn't move that Eyad?

Because it's 16 lbs and the other one's really light.

And the other one's really light.

And so obviously, there's a lot of mass.

Both of those are experiencing gravity, right?

Both of them are experiencing a normal force.

And right now, they're still.

I want to look at something else that's still take a look at this block.

It's still gravity.

Normal force.

They're balanced.

Let's see if we can make it unbalanced.

The coolest thing about acceleration, that means when something moves, changes direction or speed because of a force.

We're going to se if we can make that accelerate.

But let's see if we can try it with these three spheres.

What are you noticing about those, Nicholas?

I notice one is foam one is rubber, and one is steel.

Okay, excellent Let's start with the foam one.

Now, keep in mind the block right now, it's balanced.

It's not moving.

We've got force of gravity, normal force going up.

Now, if we add all of those forces together, that's called the net force.

Let's see if we can add another force here.

Changing the net force.

Did it make a difference?

Okay.

How about the rubber ball?

Will this net forc make it unbalanced?

Let's see.

Only a little bit.

7 centimeters.

Oh, very good.

Okay, so let's see what we get with the steel one.

Oh!

60 centimeters.

That's really good.

Really good.

A lot of mass.

A lot of acceleration.

We got some unbalanced forces and that moved.

Acceleration and Newton' second law of motion describes an object chang in speed or direction over time.

Now, objects can experience many kinds of forces, including pushing pulling, twisting or squeezing.

And those forces can be either balanced or unbalanced.

Imagine a game of tug of war.

If there are similar forces on both sides, the system is balanced and the rope doesn't move.

Even though a lot of force is applied.

But if we add more mass and pulling force to one side of the rope, it gets unbalanced and the rope begins to accelerate.

Wow, what a contest.

So we know that unbalanced force can get an object to accelerate.

But what are those forces?

What kind of forces can you think of, AvaGail?

Pushes and pulls.

Pushes and pulls.

Those are great examples of forces, Right?

So take a look at these cars right here.

Tell me what you notice about these, AvaGail.

Well, I notice this is like a little spring here, and there's not one on the other.

Okay, so there's a spring here.

And actually, let's take a look at that.

And so if I push it down, it'll pop back up.

You might recognize this.

This actually goes to a top of a bifold door to help keep the door in its track.

Now, if we push this together and I do like this and then let go, what do you think's going to happen?

What do you think?

Emmanuel, what do you think's going to happen?

I think they're going to separate.

Okay.

You think they're going to separate?

Let's try this.

We're going to put it right about in the middle of the meter stick and I squeeze it together and they separate.

Let's do it again.

Oh, that was a good one.

What are you noticing about how they traveled here, Anderson?

They both move away from the point where they started and about the same distance.

Oh, excellent.

Okay.

They really did.

It's a really close travel distance, which makes sense because we're talking about something with similar mass.

So let's try something else.

Let' change the mass in the system.

In fact, I have these extra blocks and we're goin to put them on top of this car.

And you can see I've got a little dowel and I' just going to stretch this over.

And now we've increased the mass.

Okay.

What do you think i going to happen now, Anderson?

What do you think is going to happen now?

I think only the block with the spring is going to move because this one is going to be too heavy.

It'll take a lot more energy to move.

Okay.

Let's check it out.

Oh, my gosh.

Was that a good prediction?

That kind of makes sense, doesn't it?

So we've a lot of mass here, and so this one had a lot of acceleration.

So interesting to think about if they're experiencing the same force they both have exactly the same pushing force, but this one's going to travel more.

Now, I want to try this another way.

AvaGail you mentioned pushes and pulls.

Let' try this with a pull scenario.

So I've got two blocks and I've drilled a hol where I could recess a couple of eyelets down inside there.

And we've got them attached with a rubber band.

So if we stretch them apart and then let them go.

Emmanuel, what's going to happen?

They're going to snap back and they're both experiencing the same force, right?

Because it's the same rubber band.

We've got elastic potential energy.

I'm going to pull them back at pretty similar distance.

Let's see what happens.

Oh, nice.

Did you notice where they made contact?

Right in the middle.

Right in the middle.

Same force.

Okay, let's change things up.

We're going to put a couple of extra blocks on this side and do it again.

We're going to stretch them apart and see which one accelerates more.

You guys have a prediction?

This one.

You agree?

Okay, let's take a look.

Oh, yes.

Yes, that's exactly true.

We'll do it one more time.

So they have the same force, but this one accelerates a lot more.

Here's the rule.

As far as Newton's second law, if two objects experienced the same force, the one with less mass, it's going to accelerate more.

Each time you go shopping, you get first hand experience with Newton's second law of motion.

Imagine you walk in the grocery store and begi to push the empty shopping cart.

It's easy to get the cart accelerating, but each time you ad more in the cart, you increase the cart's total mass.

Pushing a very full cart is a lot more difficult.

If you push the full car with the same force as before, you may have noticed that it takes longer to get it moving and harder to stop it.

Whoops.

STEM Challenge!

So have you been having fun investigating Newton's second law of Motion today?

Yeah.

So glad.

Now I've got a great STEM challenge for you.

You'r going to be making a catapult.

But this is not an ordinary catapult.

Yes, it's going to apply a force to a mass and make it accelerate, but that mass is going to be a marshmallow.

And so I like to call these catapults, confectionary catapults.

Now, there's something else I want you to try.

Each tabl is going to make two prototypes.

You have to decide how big your fulcrum is going to be.

You're ready to get started?

Yeah All right.

Go for it.

Have fun.

You want to start?

Go for the.

The big one.

I'll tie this thing together.

So we was creating a launcher to measur how far the marshmallows went.

This one has seven- for the STEM challenge, We received popsicle sticks, rubber bands and a spoon.

I got this.

All right?

And the first thing we did was make the fulcrum.

Oh, yeah.

A fulcrum is the poin where, like, an angle is, like, changing from, Okay, I' going to work on the other one.

I'm thinking in my head that we were going to try a bunch of popsicle sticks and then not so many to se the difference between the two.

As we were building, we realized that there is a lot more tension on the one with seven popsicle sticks than the one with two in the fulcrum and the goal was to launch them farther.

So we tried to get that angle as steep as possible.

Now who's going to make it into X?

... This is not right.

An issue we're running to is forgetting how to put the rubber bands onto the popsicle sticks to secure them.

You've got to put it in both.

I'm trying to put it in both!

We had a good strategy, but I was kind of iffy at launching i because it kept going sideways and I don't know why it didn't ever go straight.

Just went sideways.

I think the big marshmallow won't go that far because it's bigger.

Let me see yours.

Oh, there we go.

Oh, that would be a little better.

Yes.

Oh, boy.

These are looking pretty good.

I think we're just about ready to test them.

Before we test these, I do want to get a sense of how many popsicle sticks you each used in your prototypes.

Eyad, let's start with you.

What did you guys do?

We did four and seven.

Four and seven.

Excellent.

Okay, this table, AvaGail How about this one?

We did five and seven, five and seven.

Okay.

And Julia, We did seven and two, seven and two.

So seven is really, really popular.

I probably would have done that, too.

Now we're going to need to move the tables out of the way so we can line these up.

Now we're going to have some fun launching some marshmallows.

Okay, So now we're ready to test these catapults and we've got them arranged by the size of your fulcrums.

So we have a seven, seven, seven, five, four two.

And you'll notice when we look at the two, that's angled way further back than the seven.

So that's going to be kind of interesting when you try to do a launch.

We're starting with the jumbo.

So what was the mas of the jumbo marshmallow, Eyad?

The mass of the jumb marshmallows, 28.5 grams, 28.5 grams.

On your mark, 3, 2, 1, launch.

Oh, you actually got some distance.

Okay It's time for the middle size.

Grab your middle size.

What's the mass on the middle size, AvaGail?

The mass was 8.2 grams.

8.2 grams.

Let's see.

Do you think this is going to accelerate more or less?

Not only are we going to loo for distance, look for height.

You're ready.

Let's count it down 3, 2, 1, launch it.

Oh, okay.

That was interesting.

Okay, one more to test.

Get out the mini.

Julia, what's the mass on the mini marshmallow?

The mini marshmallow is 0.6 grams.

Point six.

Oh, my gosh.

Point six.

Ready?

Let's count it down.

3, 2, 1, launch.

Oh, okay.

So which one really go the best acceleration you guys?

The mini!

Of course.

Confectionary catapults are a great way to investigat Newton's second law of motion.

And the projectiles.

They're pretty sweet, too.

The crew saw how the marshmallows with less mass traveled higher and further.

But what if we changed th amount of force in the catapult?

Would the larger marshmallow travel further than it did before?

Think about it this way.

When you kick a soccer ball, it accelerates.

But the larger the ball the harder you have to kick it.

So applying more force in the catapult would also increase acceleration on a larger marshmallow or you could always try kicking the marshmallow.

So we figured out that unbalanced forces are an essential part of Newton's second law.

This time, though, Leon, you're going to be the force.

Okay?

And in fact, I hope you're no feeling unbalanced or unsteady.

You know, just for this challenge.

You notice we have a skateboard here.

What I'm going to ask you to do is you are going to pus each of the girls in sequence.

I'm going to have you push Julia first, just one single push, and then she's going to get off.

And then we're goin do the same thing with Annlyn.

And then you're going to tell us what you notice.

Okay.

All right, let's get this one set up.

Okay, So we've got Julia set.

One good push.

You ready, Leon?

Okay.

Oh, she's accelerating nicely.

Well done.

Well done.

The force.

All right.

Annlyn's next.

Okay, Leon.

Now we're going to do Annlyn and notice the difference.

Go for it.

There she goes.

Well done Annlyn.

All right.

Nice job.

I think we need to debrief this.

All right.

So that was great.

But Leon, what did you notice as far as the difference between these two?

Well, when I pushed Julia, since she's shorter, it didn't take as much force.

She greater acceleration.

And she went further.

But when I pushed Annlyn, since she's older and taller, it took more force to push her forwards with more acceleration and distance.

That's excellent.

That's.

I couldn't have said it better myself.

Now, you're probably wondering, we have something else to do and it's going to relate to my tie.

Check it out.

Have you guys ever gone bowling?

Yeah.

Okay, so we go bowling.

That's a great way t investigate Newton's second law.

We are going to apply a force with a bowling ball, and we roll that down and slam that into the mass, the pins, to try to get them all to accelerate.

Okay, I've got some bowling balls here.

Annlyn, when you go bowling, what size ball do you like to use?

About 8 lbs.

8 lbs!

I have an 8 lb ball right there.

That 8 lb ball is suspended up to the ceiling.

So it's actually hanging.

I'm going to pull it back about a meter and let it collide into our mass the box.

Annlyn how far do you thin that box is going to accelerate?

A foot, maybe a foot.

Let's give this whirl here, bring it back, Try to be consistent with our input force.

That was a pretty good prediction.

Okay.

Now you might be wondering.

All right, Dr Rob's got another one over here.

This one is 16 lbs.

16 lbs.

So, Leon, what do you think's going to happen this time?

I think it's going to be a little bit heavie to lift up the ball and drop it.

But I think the box is gonna go a little further than it did last time.

Okay.

So we're looking for a greater distance travel.

It is harder to pull back You're right about that.

Okay.

And here we go.

Okay, so we got a little more distance on that.

Now, that actually does make sense.

And I could actually feel that weight as I pulled that thing back.

Keep in mind, Newton's second law of motion says if we can apply a greater force we can get greater acceleration.

We know that the mass of an object will determine how much force will be required to change its speed or direction.

Imagine throwing a softball and then a cannonball.

That cannonball will require a lot more force because it has so much more mass.

A rocket docking in spac is another interesting example.

If the pilot needs to slow down, the faster or change direction, force from the engine will be required.

Great docking maneuver.

Sir Isaac Newton would be so proud.

Are you curious about careers in science?

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And today I'm here with Rana Mohtadi.

Rana, can you tell us where we are and what you do?

I'm a senior principle scientist at Toyota.

I work on developing materials for batteries that can be hopefully implemente in our vehicles in the future.

How is STEM involved in your work?

Well, STEM is a core component in my work.

We have physics, we have math.

We have chemistry.

So we need all of these tools to do our materials research.

So how do batteries actually work?

They allow us to store energy in the form of electricity.

Here we have what we call a power cell.

That's a battery.

Everything is lying flat here.

One side is the negative and another side is the positive electrode.

And if you have many of them, we can even run a car Wow!

I feel powered up from learning about batteries with Rana Mohtadi Explore your possibilities!

And now back to Curious Crew.

So we know that an object's acceleration depends on the net forces and the object's mass.

Right.

But when Lake and Leon both rode the cart the band pushed with a similar force but their masses were different.

Yeah.

Since Lake has less mass she traveled further and faster.

And, in Eyad's case, the mass is the same.

But the force was different.

And in its first ride, there is more acceleration.

So if you had fun investigating Newton's second law of motion today.

Yeah.

Oh, my gosh.

You said that with such force.

Okay, It's now time to go back to look at our discrepant events at the beginning.

And you might remember who has this long bungee cord that we were using.

Right.

Our Crusin' Trials.

Now, here's something I want you to think about.

We were using a special app called an Accelerometer, and I was having each of you pay attention to that.

We've got some data here.

In fact, Lake, we saw you hit a spike launch in that acceleration of three meters per second squared.

Leon came in at 1.9.

Think about that.

Eyad's first attempt also at 3.0.

But his second attempt was only 0.5.

That's interesting.

Now, I know several of you been thinking about this and you have some explanation for this phenomena.

I'm going to start with Julia.

Bring us up to speed.

Julia, what have you figured out between the comparison, especially between Lake and Leon?

We know that when there are pulling back into the van it was elastic potential energy that would push them forward When released.

Right, because they both had the same pushing force.

And because Lake had less mass and Leon, she accelerated faster.

Okay.

So we're pulling them back a similar distance.

Okay, that makes sense to me.

So what if we wanted Leo to accelerate as fast as Lake?

Emmanuel, what can we do?

We could add more pushing force.

Oh, we're increasing the pushing force.

That makes a lot of sense.

And we already know that, Leo is a force to be reckoned with.

Right.

Okay.

So now I want to think abou Eyad, because we did his twice.

What did we figure out there, Avagail?

Well, because Eyad went twice, the only thing that changed was a pushing force.

And we could tell the bigger the push, the greater the acceleration.

And that is Newton's second law of motion.

Right?

So the next time you're pushing a friend on a swing or pulling them in a wagon or you're going bowling, or you might be pushing that shopping cart in the grocery store as it gets heavier and heavier, you can give a shout out to Sir Isaac Newton for his second law of motion.

That looks like we got to get going, too.

So remember, my friends, sta curious and keep experimenting.

Get your curiosity guide and see more programs at wkar.org.

Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org.

Also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available a ConsumersEnergy.com/foundation.

And by viewers like you.

Thank you.

I know!

Season 11.

Season 11, let's roll, Let's roll.

Here she comes.

Say hi Elana.

Hi Elena!

Hello!

So you were all.. I'm gonna try that again.

La la la la.

Okay.

And to take two.

I was like movin'.

And last but not loose.

Let... That'll make it to the end of the show.

I think.