Projectile Motion

A ball is thrown horizontally from a cliff as shown. The effect of air resistance is negligible. Identify which of the following statements about the ball is/are correct. 1)the vertical velocity of the ball increases as it falls. 2)the vertical acceleration of the ball increases as it falls. 3)the vertical force on the ball increases as it falls.

1

Two identical balls X and Y are projected horizontally from the edge of a cliff. The path taken by each ball is shown. Identify which of the following statements about the motion of the balls is/are correct. 1)they take the same time to reach sea level. 2)they have the same vertical acceleration. 3)they have the same horizontal velocity.

1 and 2

A package falls vertically from a helicopter. After some time the package reaches its terminal velocity. A group of students make the following statements about the package when it reaches its terminal velocity. 1) the weight of the package is less than the air resistance acting on the package. 2) the forces acting on the package are balanced. 3) the package is accelerating towards the ground at 9·8 ms−2.

2 only

A ball is thrown horizontally at a speed of 24 meters per second from the top of a cliff. If the ball hits the ground 4.0 seconds later, approximately how high is the cliff?

39m

A ball moving with an initial velocity of 100 m/s north is given an acceleration of 10 m/s2 south. What will its velocity be after 6.0 s?

40m/s north

A projectile launched upwards will land with a maximum range for any given speed if it is projected at an angle of ______ degrees with the horizontal.

45

A 5.0 kg sphere initially at rest is allowed to fall toward the earth for a time of 5.0 s (g = 10 m/s2 ). Its velocity at the end of this time is:

50m/s down

A projectile launched at an angle of the 20 degrees will have the same range as another projectile launched at the same speed, but with an angle of ______ degrees.

70

A heavy ball is thrown straight down from a tower with an initial velocity of 50 m/s. (g = 10 m/s2 down). After 2.0 s the magnitude of its velocity is:

70m/s

A soccer player kicks a ball with an initial velocity of 10. meters per second at an angle of 30.° above the horizontal. The magnitude of the horizontal component of the ball's initial velocity is

8.7m/s

A baseball is thrown vertically upward into the air. What is the instantaneous acceleration of the ball at its highest point?

9.8m/s2 up

Two balls are released from the same height. Ball A is dropped while ball B is given an initial horizontal velocity. Which ball will land first?

Both Ball A and Ball B will land at the same time

The initial horizontal velocity of a projectile is ___ its final horizontal velocity.

Equal to

A cannon fires a shell at a fixed angle above the horizontal. Which one of the following quantities is the same throughout the shell's flight? (Ignore the effects of air friction.

It's velocity

Idaho Jo is doing physics experiments throughout the solar system. She travels to each planet and shoots a potato straight up in the air with her potato gun. She uses the same potato on each planet and the initial velocity is the same every time. She repeats the experiment on all 8 planets in the solar system. Using the information about each planet in the table, on which planet (s) will the potato reach the lowest altitude?

Jupiter

A soccer player kicks a ball with an initial velocity of 10 meters per second at an angle of 30 degrees above the horizontal.

No answer

A soldier throws a grenade horizontally from the top of a cliff. Which of the following curves best describes the path taken by the grenade?

Parabola

For a fast ball to pass the height of a batter's chest, the pitcher must aim the ball...

just above the height of the batter's chest

A shotput with a mass of 10kg and a bowling ball with a mass of 8kg are placed on a table. The balls are rolled simultaneously along the table with an initial velocity of 1.5m/s. If they are allowed to roll off the table, which will the floor first and which will land farther away from the table?

They both land at the same time and land the same distance away

The path of a projectile through space is called its:

Trajectory

A projectile is fired at an angle of 45° above the horizontal. Assume that air resistance is not significant. While the projectile is in flight, the acceleration remains constant.

True

A projectile is fired at an angle of 45° above the horizontal. Assume that air resistance is not significant. While the projectile is in flight, the horizontal component of the velocity remains constant.

True

If you launch at an angle greater than 45 degrees you will not be able to shoot as far as if you had launched at 45 degrees.

True

The rising and falling of a time projectile are equal if the launching position is __________ the landing position.

at the same height as A

A machine launches a tennis ball at an angle of 25° above the horizontal at a speed of 14 meters per second. The ball returns to level ground. Which combination of changes must produce an increase in time of flight of a second launch?

increase the launch angle and increase the ball's initial speed

The horizontal acceleration of a projectile _____as its position changes.

is zero