Unit 4: Module 1

B. 9.8 m/s

1. If a freely falling ball is somehow equipped with a speedometer, by how much would its speed reading increase for every second?

C. 30° and 60°

10. A Batang Pinoy athlete from your school throws a javelin, always at the same speed, at four different angles(30°, 40°, 60°, and 80°) above the horizontal. Which two throws cause the javelin to land the same distance away?

c. 60°

10. A ball is hit at an angle of 30o and it reaches a distance of 50 m. Given the same initial velocity, at what other angle should a ball be hit to reach the same distance.

c. 20,000kg•m/s

11. In the table above, what is the momentum of the jeepney?

a. heavy truck

11. Which has more momentum, a heavy truck moving at 30 km/h or a light truck moving at 30 km/h?

c. The time interval for stopping is greater.

12. A moderate force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the grass usually doesn't break. This is because for the egg dropped on the grass:

A. jeepney

12. Which has greater momentum, the jeepney or the motorcycle?

C. Momentum

13. The impulse experienced by a body is equal to the change in its:

B. the faster car

13. Two identical cars are travelling along EDSA. Which of the two cars would have a greater momentum?

A. the bus

14. A bus and a car are travelling along EDSA having the same velocity. Which of the two vehicles would have a greater momentum?

a. Given the same change in momentum, when the time interval is smaller the impact force is bigger.

14. In certain martial arts, people practice breaking a piece of wood with the side of their bare hand. Use your understanding of impulse to explain how this can be done without injury to the hand.

C. 150 kg m/s

15. A 25-kg girl is riding a 5-kg with a velocity of 5 m/s the East. What is the total momentum of a girl and a bike together?

b. 1.5 N s

15. A lady tennis player hits an approaching ball with a force of 750 N If she hits the ball in 0.002 s, how much impulse is imparted to the tennis ball?

B. No external force is present.

16. Which is a necessary condition for the total momentum of a system to be conserved?

B. No net external force acts on the system.

16. Which of the following is a necessary condition for the total momentum of a system to be conserved?

A. 0

17. What is the total momentum of the system before collision?

A. 0

18. If there is no external force acting on the system, what the total momentum of the system after collision?

C. Same in magnitude but opposite in direction

19. Two billiard balls approach each other at equal speed. If they collide in a perfectly elastic collision, what would be their velocities after collision?

C. Same in magnitude but opposite in direction

19. Two billiard balls approach each other with the same speed. If they collide in a perfectly elastic collision, what would be their velocities after collision?

d. -9.8m/s2

2. A sepaktakraw ball is hit vertically upward by a player. What is its acceleration after 1 second?

A. -0.10 m/s

20. A 50 kg astronaut ejects 100 g of gas from his propulsion pistol at a velocity of 50 m/s. What is his resulting velocity?

a. -0.10 m/s

20. A 50-kg astronaut ejects 100 g of gas from his propulsion pistol at a velocity of 50 m/s. What is his resulting velocity?

b. -5 m/s

3. A volleyball is tossed vertically upward, with an initial velocity of 5 m/s and caught back at the same level as when it was thrown. What is the velocity of the ball at that point?

d. Uniformly Accelerated Motion

4. The motion of an object with constant acceleration is also known as ________.

a. 0

5. A ball is thrown vertically upward. What is its instantaneous speed at its maximum height?

C

6. A fielder throws a softball to a baseman. Which diagram below shows the force(s) acting on the ball while it is on air if Fg represents the force of gravity, and Fh refers to the throwing force?

B. 45°

6. The initial velocity of Manuel playing "luksong tinik" has horizontal and vertical components that are equal in magnitude. What angle does his velocity make with the horizontal?

b. At the highest point in its flight

7. A ball is hit at an angle of 30o. At what point in its trajectory does this projectile have the least speed?

D. parabolic

7. A sepak takraw that is kicked from a height of two meters follows a path that is____________.

A. All punts have the same hang time

8. A goalie made three soccer punts at 700, 500, and 300 with varying speeds - all reaching the same maximum heights. Which statement is correct?

d. Neither its velocity nor its acceleration is zero.

8. Suppose a ping pong ball is tossed. When the ball reaches the highest point, which statement about the ball's velocity and acceleration is true?

B. 8.0 m/s

9. A volleyball is served at a speed of 8.0 m/s at an angle 35° above the horizontal. What is the speed of the ball when received by the opponent at the same height?

c. 45°

9. At what angle should a water hose be aimed in order for the water to land with the greatest horizontal range?

A. 0 m/s

Maria throws a ball straight up with an initial velocity of 10 m/s. 1. What is its velocity at the highest point?

F. -10 m/s

Maria throws a ball straight up with an initial velocity of 10 m/s. 2. What is its velocity when it returned to the elevation from where it was thrown?

D. - 9.8 m/s2

Maria throws a ball straight up with an initial velocity of 10 m/s. 4. What is its acceleration just before it hits the ground?

D. - 9.8 m/s2

Maria throws a ball straight up with an initial velocity of 10 m/s. 5. After 1 second what is the acceleration of the ball?

D. - 9.8 m/s2

Maria throws a ball straight up with an initial velocity of 10 m/s. 3. What is its acceleration at the highest point?