Projectile motion

At what point is v_y= 0 m/s?

• A

• B

• C

• D

• None of these points

At what point is v_x= 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?

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• 
• 
• 

Tags

NGSS.HS-PS2-1

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

A vector is a quantity that had

• magnitude and time
• time and direction
• magnitude and direction
• direction and rhythm 

A scalar is a quantity that had

• direction
• magnitude
• time
• color

The horizontal component of a projectile's velocity is independent of...

• it's range
• time
• the vertical component
• none of these

In the absence of air friction, the horizontal component of a projectile's velocity doesn't change as the projectile moves. 

• True
• False
• Sometimes true
• Sometimes false