Projectile Motion

What to KnowBefore you throw!

What is it?

• Projectile motion is the curved path an object follows when it is thrown or pushed near Earth’s surface

Some examples . . .

• This arched path happens when you

• Kick a soccer ball• Throw a baseball• Take a long jump• Shoot a basketball• See a water fountain• Dive into water• Watch fireworks

Why does it do that?

There are TWO motions at work* A push that moves the object

forward. This horizontal motion comes from a force* A pull from gravity brings the

object down to earth. This is a vertical motion.

Put it all together

• Combine the forward motion and the falling motion and you get an arc!

The Tricky Question

• So, let’s say you are standing on the roof of a building and have two bullets. You shoot one from a gun and drop the other one from the same height.

Which bullet lands first?

The Answer

• Most people say the bullet shot from the gun lands first, but who was their science teacher?

• The bullet from the gun is going forward faster BUT since you know all things fall at the same rate (9.8 m/s/s) they hit the ground AT THE SAME TIME!

One More Time

• An object is controlled by two independant motions. So an object projected horizontally will reach the ground in the same time as an object dropped vertically. No matter how large the horizontal velocity is, the downward pull of gravity is always the same.

http://library.thinkquest.org/2779/More.html