Projectile Motion

At the top of a projectile's path above Earth, the vertical acceleration of an object is

• is zero
• goes from positive to negative
• goes from negative to positive
• remains unchanged

A baseball was thrown with an initial velocity of 24m/s at an angle above the horizontal.  It remained in the air for 2 seconds.  Which of the following quantities was constant while the baseball was in the air?

• acceleration
• displacement
• position
• velocity

A ball is thrown horizontally from the top of a building with an initial velocity of 13m/s.  At the same time, a second ball is dropped from the top of the same building.  Which of the following is the same for the two balls?

• Their final displacement
• Their paths as they fall
• Their initial horizontal velocities
• Their final vertical velocity as they reach the ground

A 5 kg red ball is thrown horizontally at a speed of 4m/s from a height of 4 meters.  A 8 kg green ball is thrown horizontally from the same height at a speed of 6m/s.  Compared to the time it takes the red ball to reach the ground, the time it takes the green ball to reach the ground is which of the following?

• half as much
• twice as much
• four times as much
• the same

Which of the following shapes is seen in the path of  a projectile?

• straight line
• parabola
• circle
• hyperbola

If you shoot a gun and at the same time drop a bullet which will hit the ground first? Why?

• The bullet that is shot, because it is going faster
• The dropped bullet, because gravity pulls on it.
• At the same time, because the x and y components are independent of each other. 
• This cannot happen

Tags

NGSS.MS-PS2-4

The initial velocity of a projectile has a horizontal component of 5m/s and a vertical component of 6m/s.  At the highest point of the projectile's trajectory what is (A) the horizontal velocity (B) the vertical velocity?

• (A)25m/s, (B) 10m/s
• (A) 5m/s,  (B) 0m/s
• (A) 10m/s, (B) 24m/s
• (A) 0m/s, (B) 3m/s

If I throw a crayon straight up at 12 m/s, how fast is its velocity when I catch it at the same height?

• -6 m/s
• -12 m/s
• -18 m/s
• -24 m/s

What is the horizontal acceleration of a projectile?

• 0 m/s²
• -9.8 m/s²
• 0 m/s
• -9.8 m/s

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

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