Are you feeling curious?

Yeah!

Going up.

Today on Curious Crew Oh, right back inside.

What goes up must come down.

They both landed at the same time.

But what's the driving force of this phenomenon?

The heavier objects resist the change of motion.

Thanks for dropping in.

As we investigate the science of falling objects.

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 savings 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 at ConsumersEnergy.com/foundation and by viewers like you.

Thank you.

(MUSIC) Hi, I'm Rob Stephenson 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 Curiousity!

That's exactly right.

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

In fact, Eshaan, I'm going to have you help me out.

Okay?

We have a couple of bowling balls down here on this mat.

And Eshaan, I'm going to ask you to pick up each one of these.

One at a time.

Hand them to me.

Tell me what you notice.

Go for it.

Okay.

Oh, this one's way heavier.

This one.

This one is way heavier.

This one is 16 pounds compared to eight.

Okay, We are going to hold these out over the mat and drop them.

But I want us to predict.

Charlee, what do you think will happen if I drop these and let them go at the same time?

I think the heavy one will hit the ground first.

Okay, let's give it a whirl.

Interesting.

What did you notice, Charlee?

Both of them hit the ground at the same time.

Exactly right.

Which seems a little perplexing because that ball is clearly heavier than the other one.

Okay, let's look at something else.

We have a ball launching system here, and this is an electric ball launching system.

And you'll notice there are some balls stacked up inside.

Now, if you look at the output where the ball is going to come out, I have that directly in line with the target here on the board.

In fact, we even used a string level to make sure it's exactly level.

It's going to be firing out balls about every four or 5 seconds.

And my question for you, Varsha, is, do you think we can hit the target with the ball?

Yeah, obviously, because they're lined up in the same way.

So obviously.

Awesome.

Nitya, can you do me a favor?

Can you turn that on?

Now you'll notice it takes just a minute to get fired up here just a little bit and just push that straight back.

Perfect.

And so you'll see the ball start to drop down as it is...

Okay.

So let's take a look at another one here as it comes firing out.

Oh, interesting.

Couple more.

Let's take a look.

Think we're going to hit it Varsha?

I'm not feeling very confident anymore.

Oh, my goodness.

Oh, one more Varaha What are you noticing?

Wouldn't even come close to hitting the target.

It keeps going below, doesn't it?

Yeah.

Okay.

Nitya you can go ahead and turn that off.

Now, these are a little perplexing.

I'm going to ask three of you to do a little scientific modeling to see if you can figure out these phenomena and explain them at the end of the program.

You can use your background, knowledge, anything you'll learn along the way.

So who would like to participate in a modeling moment today?

Okay, Bhavya, Chloe and Zaydin.

Excellent.

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

What do you think Eshaan?

Probably something about gravity Good thinking.

We're going to be investigating falling objects.

Stick around.

You don't want to fall behind.

Let's see if we can figure this out.

It's surprising that the bowling balls land at the same time.

I know one was twice as heavy.

Isn't there more gravity acting on a heavier one?

I mean, there has to be.

I was thinking about the other discrepant event, too.

It seems like the ball should have hit the target.

I mean, it came out with a lot of force and it didn't have to travel that far.

You probably learned at a very young age that things fall down, including us.

Objects fall because of gravity.

That invisible force that pulls objects together.

Now every object has mass, which is the amount of matter in something, and the greater the mass, the greater the gravitational force.

We can even feel that force and measure it.

That would be our weight.

And a surprising fact about falling objects on Earth is that they will accelerate at a rate of 9.8 meters per second, per second, no matter how much they weigh.

So let's see if we can gather some evidence to see if we can figure out those phenomena.

And it's going to start with the spheres that are in front of each of you.

Chloe, can you pick yours up and describe to me what you notice?

This one is a lot heavier.

Oh, okay.

The big one has a mass of 151 grams.

The other one 16.

So that's a pretty big difference.

Now, what I'm going to ask you each to do is you're each going to hold the spheres up just about ten, 12 inches above the pad.

And on the count of three, I'm going to have you drop them and tell me what you notice.

You ready?

3,2,1 drop.

Zaydin, what did you notice?

They both landed at the same time.

Okay.

Which is kind of unusual, right?

Did you get a similar result over there, You too.

Okay, good.

So it is really difficult to make sure we're letting them go at the same time and even holding them level.

So we're going to try it again with this contraption up here.

You'll notice again, I have two different sized spheres and they're supported with this little yellow shelf.

Now that shelf is going to slide out of the way.

Once I pull this pin.

And as soon as that shelf slides out of the way, they're going to drop down onto the pad, watch it closely and see if we get a similar result.

Whatd you notice?

Whatd you notice?

they both landed at the same time Zaydin.

Good job.

And what would that tell us about the speed Varsha?

They were traveling at the same speed that is an excellent conclusion.

Okay, so let's think about this for just one second.

Why would they be traveling at the same speed when one of them is clearly heavier?

We know this is experiencing more gravity.

We can feel it, right?

So we know this is experiencing more gravity, but that also means it's experiencing more inertia.

It's resistance to its change in motion.

So it takes more force to get this to start falling and as a result, they both fall, accelerate and land at the same time.

Now, amazingly, in 1634, Galileo proved mathematically that objects on Earth fall and accelerate at 9.8 meters per second squared.

Okay, I want to show you something else.

Check out this little frame I have here, and I'm going to hold this little star toy because it's just cute and I'm going to put it right in the middle and I'm going to drop them both at the same time.

And if you watch closely, it will look like the star is suspended right in the middle, almost like it's floating.

Ready, 3,2,1 drop.

Could you see that this is even more impressive to see in slow motion?

I got to tell you a little story.

When I was a kid, I went to an amusement park and I got into this ride with several other people and it went straight up.

We were really, really high up in the air and suddenly the whole car drops.

So you're falling and right at the bottom it engages on a track and you zip along onto your back safely to a stop.

So of course, I was curious, when I was at the top, I pulled a penny out of my pocket and I held it right above my lap.

And as soon as I started to fall, I let the penny go.

And guess what?

That penny floated right above my lap.

And right before we hit the bottom, I grabbed the penny.

Isn't that amazing?

Varsha, What can we conclude?

No matter the mass falling objects accelerate at the same rate.

So they're going to accelerate at the same rate, and on earth, that means 9.8 meters per second.

Per second.

It seems like heavier objects should fall faster, but we have seen that they don't.

In 1586, Simon Steven and a friend tested this idea by dropping two lead balls from a 30 foot church tower, even though one of the balls was heavier than the other, they hit the ground at the same time.

No one could explain why.

That is not until Galileo.

In 1634, he figured out that all falling objects speed up as they fall.

But the acceleration was the same 9.8 meters per second squared.

That means even though the balls have different weights, they will land at the same time.

So let's see if we can apply what we figured out so far.

Charlee, I'm going to ask you to help me.

Can you pick up both of those hammers?

And I'd like you to share with us any differences that you notice.

Ones heavier than the other.

You're right.

One of them is 20 ounce hammer, and the other one is a 16 ounce hammer.

So, Charlee, if you hold those out and drop them at the same time, what should happen?

I think they're going to fall at the same time.

Okay, let's try it.

Very good prediction.

Did it confirm your guess?

It sure did.

Excellent.

Okay, so let's try this.

Eshaan, you've got a book and a feather there, and I'm going to ask you also to drop them from the same height at the same time.

What do you think's going to happen?

Well, I think the feather is going to fall slower than the book.

All right, let's try it.

I think that was a good prediction.

Now, according to Galileo, all objects falling on earth should be falling and accelerating at the same rate.

So what's going on here with the feather Eshaan?

I think that the feather encountered some air resistance.

That makes a lot of sense.

Let's think for a minute.

Is there a way we could get these two items to fall at the same rate?

Sagan what could we try?

You could try putting the feather on the book.

Wanna try that.

Okay.

Put it on the book and let's try that.

Now, that totally worked.

Now let's think about why that book has a lot of mass.

It easily can move those air particles out of the way, much more so than a feather.

So let's think about this.

If we could eliminate some of the air and drop something that doesn't have very much mass, that could be kind of interesting.

Take a look at this tube.

You're going to notice inside this tube there is a black screw and a paper circle.

And when I flip it over, the black screw goes tumbling down and the paper circle flutters down to the bottom.

Now, if we can remove some of the air from the tube using this pump, we're going to have some interesting things to observe.

Let's just hook this up and turn it on for a minute.

Now, you're probably wondering, how am I keeping it sealed?

There is a valve that I can close right here, so I can't let any air in or out.

Now, watch closely.

Let's see if you see a difference with the movement of the paper circle.

Charlee, whatd you notice?

It falls faster.

It falls faster than it did before, doesn't it?

Now, if we take all of the air out, those two items will fall exactly at the same rate because it's going to be falling at 9.8 meters per second squared.

Now, this just reminds me of a really interesting experiment that was done in a place with no air.

Watch this.

In 1971, there was an Apollo 15 astronaut named Dave Scott who was on the moon, and he wanted to conduct a falling object experiment.

It was the same one Galileo imagined many centuries before.

In one hand, he held a falcon feather and then the other a hammer.

He dropped them both at the same time and saw that they hit the ground simultaneously.

This is because there's no air on the moon to slow the feather down.

So both objects will accelerate down at the same rate and I apologize for my bad puns now.

Now I know these discrepent events sparked your interest.

It can be a dizzying experience.

Doctor Rob does Joke a lot.

I know I threw a curveball.

His puns.

The best.

You can take that to the bank.

They always make a smile and laugh, even no matter how bad they are.

Some just can't take the heat.

His jokes, some of them are a little more dad jokes.

So don't rocks rock you guys.

Yeah, Yeah, but we can't take them for granite.

Sorry.

They're very cheesy, but they're very, very funny.

Even that can be pretty eggs-citing.

Stem Challenge so have you been having fun investigating falling objects today?

Yes.

Oh, I'm so glad.

Now we have seen how air resistance can slow down falling objects.

Right.

We're going to leverage that today.

In fact, you're going to be making plastic parachutes to see if you can slow the descent of an eight gram washer.

Now, I've asked each table to make a different sized parachute, so we can compare and analyze results.

Are you ready to get started?

Yeah.

Let's do it.

Okay.

So I think we can all help Right?

Right here.

Let's unfold this Today Dr.

Rob has us making some plastic parachutes.

I'll measure it, and then I'll do, like, little snips.

Right about there.

Dr.

Rob has is using cut up pieces of garbage bag.

We're using scissors to rulers, a washer, twisty ties and some string.

First we have to measure the trash bag 20 centimeters on each side.

Then we have to cut the strings into the correct length.

Are you cutting the string?

Okay good.

I'll loosely tie them and you can tighten them and make them smaller.

And you have to tie the string to the corners of the garbage bag.

No!

Then we tie the knot at the very end of all four strings, put the washer on and connect it all with twisty ties and it makes a little parachute.

Got lots of time.

It's so tiny.

I think because our parachute was the biggest parachute, there would be a lot of air resistance and I think it will land pretty slowly.

I guess that works.

When Dr.

Rob drops our parachute, I am pretty excited to see what happens.

Yes, I am so excited to see whether our parachute works.

Okay.

These are looking pretty good.

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

But before we do, I'm curious, what size did we end up with?

Let's talk to Varsha first.

What size for each leg of your parachute over there.

What is it?

It was 20 centimeters.

20 centimeters.

Okay.

And how about on this one, Ben?

You did, what, 40 centimeters?

40 centimeters.

And this one?

60 centimeters.

Zaydin 60.

Okay, So we have a nice comparison with 20, 40, 60.

And then we're going to time the descent and see how we do.

I've got a great idea of how we can test these.

But first, we're going to need to move the tables.

This should be interesting.

So this power lift should give us the necessary height for us to drop each of the parachutes.

And I'm going to ask a couple of you to help me out.

Ben, I've given you a little stopwatch there.

I'm going to ask you to time the descent of each one.

And, Varsha, can you record the results?

All right.

Looks like it's time for going up.

Table one.

Ready, Ben?

Ready.

Three, two, one.

Drop.

Table two.Three, two, one, drop.

Table three.

Three, two, one, drop.

4 seconds.

Okay, let's compare those results.

I'm coming down.

Okay, Perfect.

Now that we're here, Varsha, can you report out and tell us the data for 20 centimeters until 2 seconds for the parachute to come down.

And for 40 centimeters, it took 2.8 seconds for the parachute to come down.

And for 60 centimeters, it took 4 seconds for the parachute to come down.

So we definitely see a difference.

Right.

So what can we conclude on this Zaydin?

The bigger the parachute, the longer it takes to fall.

And that makes a lot of sense, doesn't it?

We call that decreasing.

It's terminal velocity.

You can even try making your own plastic parachute and then compare your results when a ball falls, the distance it travels is proportional to the square of elapsed time.

That means with each second it falls, the faster it goes and the more distance it covers.

But what about skydivers?

Well, they speed up too, but they encounter a lot of air resistance or drag pushing up and slowing them down to slow down.

They can spread out and catch more air.

Eventually, pushing air will prevent them from accelerating any more, and that's called terminal velocity.

Looks like it's time to open the parachute, increase drag and decrease the terminal velocity much better.

And what a view.

So we've covered a lot of territory today, but what is one of the things that we figured out Bhavya?

Objects on Earth fall at 9.8 meters per second squared.

It's exactly right.

What is something else that we've learned Ben?

Air slows down objects when they fall.

Exactly.

What about an object that's already in motion traveling in a horizontal way and then suddenly falls?

Does that horizontal motion change the acceleration of that falling?

We're going to test that, see if we can figure it out.

And we're going to use this little device right here.

It's pretty interesting.

You'll notice that there's this clamp up here with this board and it's level on each end is a cube.

Cube has the same mass, but this cube is actually attached on the end of the rod, and this one is in front of the rod.

You'll also notice a spring here.

Now, when I lift this trigger, the rod will thrust forward, knock this one off, moving it horizontally and dropping this one.

What we want to see is do they land at the same time or not?

This one you're going to want to observe closely, but you can also listen to see what you notice.

Let's try it.

What did you notice, Nitya?

They fell at the same time.

So what can we conclude about horizontal motion?

The horizontal motion has no effect on the vertical acceleration.

Okay, but let's try this one more time and Ben can you just roll this cart down on the track?

Well, that's nice and smooth.

Boy, that rolls beautifully.

Now, one of the things you'll notice here, I've got a little ball and inside is a spring loaded launcher.

I'm going to push the ball down inside and we're going to turn this on.

And when I turn it on and push it down the track, this little piece of metal will go through a little eye and launch the ball straight up.

Now Ben I'd like you to make a prediction.

What do you think will happen if the ball is launched up while the car is moving down the track?

I think the ball will launch up, the cart will move and then will fall in the same spot.

All right.

Let's give it a whirl.

Oh, right back inside.

Now, that's kind of unusual.

Bhavya, what can we conclude there?

I think we can conclude that, again, the horizontal motion doesn't really have an effect on the vertical motion.

Exactly right.

That ball is launched up.

It's going to fall, continue to come down, accelerating at 9.8 meters per second squared.

The really strange thing, though, is the perspective for us.

We know that it went up and it must have been having a curved path to be able to land in the moving car.

Think about it this way.

If you are riding in a car and you toss a ball up in the air, the ball just lands in your hand, right?

It isn't affected by that horizontal motion.

The strange thing though, is if we were teeny tiny and sitting on that car and we saw that ball launch up, it looked like it went straight up and straight back down.

The science of falling objects is really, really interesting.

I've just thought of another great investigation our viewers can try at home.

Check this out.

Here's a fun investigation.

You can try outside, take a paper or Styrofoam cup and poke a hole through the bottom with a pencil, cover the hole with your finger and fill the cup with water.

Take it outside, remove your finger so it starts to leak, then drop it from as high as you can reach.

The water stops leaking as it falls.

That's because the water and cup are both falling and accelerating at the same rate.

Amazing.

Are you curious about careers in science?

Hi, I'm Olivia.

And today I'm here with Dawn McKenzie.

Dawn to tell us where we are and what you do.

Yes, we're in Brighton, Michigan, and I'm a hot air balloon pilot and we're getting the balloons set up to take flight.

What aspects of STEM are used in balloon piloting?

There are many aspects of STEM used in balloon piloting.

We analyze the weather in many ways to make sure it's safe.

So there's a lot of physics, air density and science that goes into hot air ballooning.

What is the most rewarding part of being a balloon pilot?

Being a balloon pilot is very rewarding.

It's so much fun.

There's so many people we meet along the way and we have a really wonderful balloon community up, up and away.

All right.

Oh, wow we're high.

being in a hot air balloon is nothing like I could have ever imagined.

My knowledge about stem is sky high thanks to balloon pilot Dawn McKenzie.

Explore your possibilities.

And now back to Curious Crew.

So baffling bowling balls are the same as the Hammers.

Even though one's heavier, they still land at the same time.

Right, just like the surprising spheres, the heavier objects resist the change in motion.

Exactly.

And they still accelerate at the same rate.

I agree.

I still find it strange that the launched balls didnt hit the target.

It must start falling as soon as it leaves the launcher.

I wonder what would happen if Dr.

Rob raised the angle and then launched it.

So have you had fun investigating falling objects today?

Yeah.

I'm so glad we now have to return to these discrepant events and I do hope those explanations are falling into place.

But what have you figured out about our baffling bowling balls Chloes?

We know that both bowling balls were speeding up as they fell due to gravity Right.

And both were experiencing the same rate of acceleration, and that's why they fell at the same time.

So why does one ball feel heavier Bhavya?

Well, one of the balls has more mass and hence experiences, more gravity.

But that also means it has more inertia too.

Excellent thinking.

So if we've got a heavy ball, it's experiencing a lot of gravity.

But that also means it needs more force to begin falling.

So then they both fall, they both accelerate at the same rate and they hit the ground simultaneously.

Nice job.

Okay, what about our on target phenomenon here, Zaydin?

We know that the ball, when it exit the launcher, it drops below, so it's automatically going to go lower than the target.

Okay, excellent.

So what could I do if I wanted to try to hit the target, maybe shoot the ball up on the angle.

So when it drops, it goes on the target instead.

I think we should try that.

Let's turn this on.

And I'm actually going to change its exit path.

We're going to crank this up so it's no longer horizontal and let's start to see if we can get it closer and closer and closer to the Oh, that was pretty close.

So you will notice as it goes out, Oh, I even went really high.

We can compensate for that gravity effect by shooting it higher or lower, shooting it higher, and we are likely less to hit the target on that curved path when it's coming down.

So I've got another wondering if I put it back in the horizontal motion.

Bhavya, I want you to think about this.

And I had another ball and I dropped it right from the same height at the exact same time that the ball was exiting.

What would happen?

Well, I think they'd still fall at the same time because they're both experiencing the same amount of gravity, and the horizontal motion doesn't really affect the vertical motion.

Looks like you explain that in one fell swoop.

Good job, crew.

So remember, my friends, stay 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 at ConsumersEnergy.com/foundation and by viewers like you.

Thank you.

Thank you.

Okay.

Bhavya.

Chloe and Eshaan.

No.

Ishan.

What do you think?

somthing about the ... Yeah.

Yeah.

I mean, you and me both, buddy.

Wah, wah, wah.

How do you do that?

I will teach you later.

1001 modeling moments.

Take 1 1001 Investigation 3.

Take one.

Nice job, Nitya.