Intro to Projectile Motion

What is the horizontal acceleration of a projectile?

• 0 m/s²
• -9.8 m/s²

• A

• B

• C

• D

• A

• B

• C

• D

At what point is v_y= 0 m/s?

• A

• B

• C

• D

• None of these points

Which vector pair (arrow pair) correctly represents the acceleration and velocity at point P?

• 
• 
• 
• 

Who do you agree with?

• Anita: “A projectile’s v_x changes because of gravity, and its v_y remains constant.”

• Barry: “Both v_x and v_y are constant.”

• Chris: “A projectile has no acceleration in the vertical dimension but it does accelerate horizontally.”

• Dave: “A projectile has vertical acceleration and a constant horizontal velocity”

A ball is thrown into the air at some angle, with initial velocities v_x (horizontal) and v_y (vertical). At the very top of the ball’s path:

What is its velocity in the horizontal direction?

• v_x

• Greater than v_x

• Zero

A ball is thrown into the air at some angle, with initial velocities v_x (horizontal) and v_y (vertical). At the very top of the ball’s path:

What is its velocity in the vertical direction?

• v_y

• Greater than v_y

• Zero

If you throw a baseball straight up, what is its velocity in the vertical direction at the highest point?

• 9.8 m/s²
• 9.8 m/s
• 0 m/s²
• 0 m/s

What is the vertical acceleration of a projectile?

• 0 m/s²
• -9.8 m/s²