1. Vectors and projectiles

2. Which of the following remains constant while a projectile is in the air?
The horizontal acceleration
The vertical acceleration
The horizontal component of the velocity
All of the above.

3. A bullet is fired horizontally and hits the ground in 0. 5 seconds
A bullet is fired horizontally and hits the ground in 0.5 seconds. If it had been fired with twice the speed in the same direction, it would have hit the ground in ____. (Assume no air resistance.)
a. less than 0.5 s.
b. more than 0.5 s.
c. 0.5 s.

4. When a rock thrown straight upward gets to the exact top of its path,
Its velocity and acceleration are zero.
Its velocity is zero and its acceleration is -9.8 m/s2.
Its velocity and acceleration both depend on how high it was thrown.
Its velocity is -9.8 m/s2 and its acceleration is zero.

5. Elizabeth and Anne are playing kickball on the roof of HCHS, when Elizabeth kicks the ball off the roof. If the roof is 8.3 meters off the ground, how long did it take the ball to hit the ground?

6. At the instant a bullet is fired horizontally from a gun, an identical bullet is dropped from the same height. Which of the bullets hits the ground first?
Impossible to determine without knowing the horizontal velocity of the fired bullet.
The fired bullet.
The dropped bullet.
Neither, they drop at the same time.

7. Avery and Alexis are riding the bus when they see Lee
Avery and Alexis are riding the bus when they see Lee. Avery throws a book out the window at the exact moment that the bus passes Lee.() If the bus window is 1.8m from the ground, and the bus is traveling at a very high speed of 50 m/s, how far away from Lee will the book land?

8. Roll a bowling ball off the edge of a table
Roll a bowling ball off the edge of a table. As it falls, its horizontal component of velocity ___.
a. decreases
b. remains constant
c. increases

9. At what point in its path is the vertical component of the velocity (vy) of a projectile the smallest?
The instant it is thrown.
Halfway to the top.
At the top.
As it nears the top.
It is the same throughout the path.

10. A football is kicked into the air at an angle of 45 degrees with the horizontal. At the very top of the ball's path, its acceleration is _______. (Neglect the effects of air resistance.)
a. entirely vertical
b. entirely horizontal
c. both vertical & horizontal
d. not enough information

11. Carlee throws a baseball at an angle of 55° from East at a velocity of 35 m/s. What was the velocity of the ball in the x and y directions?

12. An object is undergoing free fall motion
An object is undergoing free fall motion. As it falls, the object's ____.
a. speed increases
b. acceleration increases
c. both of these
d. none of these

13. True or false:
A projectile must be moving in the downward direction.

14. True or false:
A projectile could begin its projectile motion with a downward velocity.

15. True or false:
A projectile with a rightward component of motion will have a rightward component of acceleration.

16. True or false:
The horizontal velocity of a projectile changes by 9.8 m/s each second.

17. True or false:
A projectile with an upward component of motion will have a upward component of acceleration.

18. True or false:
As a projectile rises towards the peak of its trajectory, the vertical acceleration will decrease; as it falls from the peak of its trajectory, its vertical acceleration will increase.

19. True or false:
Consider a projectile launched from ground level at a fixed launch angle and a variable launch speed and landing at ground level. The vertical displacement of the projectile during the first half of its trajectory (i.e., the peak height) will always increase as the launch speed is increased.