Physics Unit 1

6) A hockey puck slides along an icy pond. Without any kind of friction, the force needed to sustain sliding is:

0 N

12) When riding an elevator down from the 20th floor to the 1st floor, one would feel heavier

1-5

35) A freely falling object has an instantaneous speed of 10 m/s. One second later its speed will be:

10 m/s

24) Alex who has a mass of 100-kg skateboards at 10.0 m/s smacks into a brick wall and comes to a dead stop in 0.2s. His force of impact is:

10,000

27) A rolling freight car collides with an identical freight car at rest. After coupling they roll with a speed of 2 m/s. From this information the initial speed of the rolling freight car was:

2 m/s

22) A 1000-kg truck traveling at 10 m/s brakes to a stop in 5 s. Its average braking force is:

2,000 N

7) A 1000-kg car accelerates at 2 m/s2. What is the net force exerted on it?

2,000 N

18) When Mike sprints 100 yards in 20 seconds, his average running speed is:

300 yard per minute

30) A roadie pushes a pair of speakers 2 m with a force of 20 N. The work done by the roadie is:

40 j

26) A cart is pushed to the right by a 10-N force. At the same time, a boy pushes it to the left with a 5-N force. The net force exerted on the cart is:

5 N to the right

25) What is the resultant of a horizontal 4-unit vector combined with a horizontal 3-unit vector (both with the same direction) ?

5 units

20) A 500-N skydiver reaches terminal velocity at 90 km/h, with an air resistance of:

500 N

33) Gilbert is attracted toward Earth by a 500-N gravitational force. The Earth is attracted toward Gilbert with a force of:

500 N

10) A box is dragged at a constant velocity across a level surface by 6 N of force. What force of friction acts on the box?

6 N

29) If the force acting upon an object was 120 N and it had an acceleration of 20 m/sec2, what was its mass?

6 kg

21) A heavy and a light ball are dropped at the same time from a high tower. The ball to reach the ground first, assuming no air resistance, will be the:

Both of the balls

8) A heavy ball hangs by a string, with a second string attached to its bottom A quick pull on the bottom string breaks the:

Bottom string

4) Girls wearing gym shoes win in a tug-of-war against boys wearing socks on a smooth floor because the girls are able to:

Exert more force on the slippery floor

3) A long-barrel cannon fires a faster cannonball than a short cannon because the ball is given more:

Impulse

5) A glance at the speedometer in a vehicle will tell you your:

Instantaneous speed

23) Lightweight Jane and a heavyweight Jack jump from an airplane and open their same-sized parachutes at the same time. Who reaches a state of zero acceleration first?

Light woman

16) When Harry kicks a can, he exerts a greater force on the can if it is:

Lighter

11) A moving probe in space continues in its motion due to:

Own inertia

32) A huge GMC truck and a Honda Civic traveling at the same speed collide head-on. The collision force is greatest on the:

Same force

19) A skydiver who falls at constant velocity is at:

Terminal velocity

9) A heavy ball suspended by a string has a second string attached to its bottom (Figure 2.7 above). A slow pull on the bottom string breaks the:

Top string

17) When you push on a car with twice the force for twice the time, you impart:

Twice the impulse

2) A ball is tossed vertically upward. At the top of its path, its velocity is:

Zero

13) A given net force accelerates a cart along a straight-line path. If the mass of the cart somehow doubles, its acceleration:

be half

1) Impulse involves the time that a force acts. Work involves the:

distance

31) A cannonball is fired by a cannon. The much smaller recoil speed of the cannon involves differences in:

masses

34) An iron ball and wooden ball of the same size are dropped simultaneously from a high cliff. When hitting the ground below, the iron ball has a greater:

momentum

28) Compared with an apple's mass on Earth, the mass of the same apple on the Moon is:

remains the same

14) Two identical billiard balls roll toward each other with equal speeds. The net momentum of the two-ball system is:

zero

15) A 100-N falling object encounters 100 N of air resistance. The net force on it is:

zero net force