The Bronx High School of Science Version A Physics - Exam

The Bronx High School of Science Physics - Exam

Base your answers to questions 1 through 3 on the following information. In the diagram below, a 10.kilogram sphere, A, is projected horizontally with a velocity of 30. meters per second due east from a height of 20. meters above level ground. At the same instant, a 20.-kilogram sphere, B, is projected horizontally with a velocity of 10. meters per second due west from a height of 80. meters above level ground. [Neglect air friction.]

1. Initially, the spheres are separated by a horizontal

distance of 100. meters. What is the horizontal

separation of the spheres at the end of 1.5 seconds?

(A) 40. m

(C) 45 m

(B) 15 m

(D) 30 m

2. The magnitude of the horizontal acceleration of

sphere A is

(A) 0.0 m/s2

(C) 9.8 m/s2

(B) 2.0 m/s2

(D) 15 m/s2

3. Compared to the vertical acceleration of sphere A, the vertical acceleration of sphere B is

(A) the same

(C) one-half as great

(B) twice as great

(D) four times as great

Version A ______

Version A

Page 1

Base your answers to questions 4 and 5 on the information and diagram below.

A student standing on a knoll throws a snowball horizontally 4.5 meters above the level ground toward a smokestack 15 meters away. The snowball hits the smokestack 0.65 second after being released. [Neglect air resistance.]

4. At the instant the snowball is released, the horizontal component of its velocity is approximately

(A) 23 m/s

(B) 9.8 m/s

(C) 6.9 m/s

(D) 17 m/s

5. Approximately how far above the level ground does the snowball hit the smokestack?

(A) 0.4 m

(B) 2.4 m

(C) 0.0 m

(D) 4.5 m

6. The diagram below shows the muzzle of a cannon located 50. meters above the ground. When the cannon is fired, a ball leaves the muzzle with an initial horizontal speed of 250. meters per second. [Neglect air resistance.]

7. A baseball player throws a ball horizontally. Which statement best describes the ball's motion after it is thrown? [Neglect the effect of friction.]

(A) Its vertical speed increases, and its horizontal speed increases.

(B) Its vertical speed remains the same, and its horizontal speed increases.

(C) Its vertical speed increases, and its horizontal speed remains the same.

(D) Its vertical speed remains the same, and its horizontal speed remains the same.

Which action would most likely increase the time of flight of a ball fired by the cannon?

(A) giving the ball a greater initial horizontal velocity

(B) moving the cannon closer to the edge of the cliff (C) positioning the cannon higher above the ground (D) pointing the muzzle of the cannon toward the

ground

Version A

Page 2

Base your answers to questions 8 through 10 on the information and diagram below.

A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 meters high.

11. The diagram below shows a student throwing a baseball horizontally at 25 meters per second from a cliff 45 meters above the level ground.

8. What is the horizontal velocity of the ball just

before it reaches the ground? [Neglect air

resistance.]

(A) 34.3 m/s

(C) 68.6 m/s

(B) 20.0 m/s

(D) 9.81 m/s

9. What is the initial vertical velocity of the ball?

(A) 9.81 m/s

(C) 60.0 m/s

(B) 20.0 m/s

(D) 0 m/s

10. What is the approximate total time required for the ball to reach the ground? [Neglect air resistance.]

(A) 12.2 s

(C) 3.00 s

(B) 2.04 s

(D) 3.50 s

Approximately how far from the base of the cliff

does the ball hit the ground? [Neglect air

resistance.]

(A) 75 m

(C) 230 m

(B) 140 m

(D) 45 m

Base your answers to questions 12 and 13 on the information and diagram below.

A child kicks a ball with an initial velocity of 8.5 meters per second at an angle of 35? with the horizontal, as shown. The ball has an initial vertical velocity of 4.9 meters per second and a total time of flight of 1.0 second. [Neglect air resistance.]

Version A

12. The horizontal component of the ball's initial

velocity is approximately

(A) 7.0 m/s

(C) 4.9 m/s

(B) 13 m/s

(D) 3.6 m/s

Page 3

13. The maximum height reached by the ball is approximately

(A) 1.2 m

(C) 4.9 m

(B) 2.5 m

(D) 8.5 m

14. A plane flying horizontally above Earth's surface at

100. meters per second drops a crate. The crate

strikes the ground 30.0 seconds later. What is the magnitude of the horizontal component of the crate's velocity just before it strikes the ground? [Neglect friction.]

(A) 394 m/s

(C) 294 m/s

(B) 0 m/s

(D) 100. m/s

Base your answers to questions 15 through 19 on the information below.

18. What is the total displacement of the ball from the time it is thrown until it returns to the point from which it was thrown?

(A) 9.8 m

(C) 0 m

(B) 248 m

(D) 49 m

19. Which graph best represents the relationship between velocity and time for the motion of the ball?

(A)

(C)

A ball is projected vertically upward from the surface of the Earth with an initial speed of +49 meters per second. The ball reaches its maximum height in 5.0 seconds. (Disregard air resistance.)

15. Which graph best represents the relationship between displacement and time for the motion of the ball?

(A)

(C)

(B)

(D)

20. A rock is thrown horizontally from the top of a cliff at 12 meters per second. Approximately how long does it take the rock to fall 45 meters vertically?

[Assume negligible air resistance.]

(A) 1.0 s

(C) 3.0 s

(B) 5.0 s

(D) 8.0 s

21. Above a flat horizontal plane, an arrow, A, is shot horizontally from a bow at a speed of 50 meters per second, as shown in the diagram below. A second arrow, B, is dropped from the same height and at the same instant as A is fired.

(B)

(D)

16. What is the maximum height reached by the ball?

(A) 122.5 m

(C) 245 m

(B) 49.0 m

(D) 24.5 m

17. What is the velocity of the ball just as it returns to the point from which it was thrown?

(A) +49 m/s

(C) 0 m/s

(B) ?49 m/s

(D) ?9.8 m/s

Neglecting air friction, compared to the amount of

time A takes to strike the plane, the amount of time B takes to strike the plane is

(A) less

(C) the same

(B) greater

Version A

Page 4

22. A ball is thrown horizontally at a speed of 20. meters per second from the top of a cliff. How long does the ball take to fall 19.6 meters to the ground?

(A) 1.0 s

(C) 9.8 s

(B) 2.0 s

(D) 4.0 s

23. A book is pushed with an initial horizontal velocity

of 5.0 meters per second off the top of a desk. What

is the initial vertical velocity of the book?

(A) 2.5 m/s

(C) 0 m/s

(B) 10. m/s

(D) 5.0 m/s

Base your answers to questions 24 and 25 on the diagram below which shows a ball projected horizontally with an initial velocity of 20. meters per second east, off a cliff 100. meters high. [Neglect air resistance.]

26. A 2-kilogram block is dropped from the roof of a tall building at the same time a 6-kilogram ball is thrown horizontally from the same height. Which statement best describes the motion of the block and the motion of the ball? [Neglect air resistance.]

(A) The 6-kg ball hits the ground first because it has more mass.

(B) The 2-kg block hits the ground first because it has no horizontal velocity.

(C) The 6-kg ball hits the ground first because it is round.

(D) The block and the ball hit the ground at the same time because they have the same vertical acceleration.

27. A red ball and a green ball are simultaneously thrown horizontally from the same height. The red

ball has an initial speed of 40. meters per second

and the green ball has an initial speed of 20. meters

per second. Compared to the time it takes the red ball to reach the ground, the time it takes the green ball to reach the ground will be

(A) the same

(C) half as much

(B) four times as much (D) twice as much

Base your answers to questions 28 and 29 on the information below.

24. How many seconds does the ball take to reach the ground?

(A) 2.0 s

(C) 9.8 s

(B) 20. s

(D) 4.5 s

25. During the flight of the ball, what is the direction of its acceleration?

(A) westward

(C) upward

(B) downward

(D) eastward

Projectile A is launched horizontally at a speed of 20. meters per second from the top of a cliff and strikes a level surface below, 3.0 seconds later. Projectile B is launched horizontally from the same location at a speed of 30. meters per second.

28. The time it takes projectile B to reach the level

surface is

(A) 4.5 s

(C) 3.0 s

(B) 2.0 s

(D) 10. s

29. Approximately how high is the cliff?

(A) 44 m

(C) 29 m

(B) 60. m

(D) 104 m

Version A

Page 5

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download