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A 1000 kg sportscar accelerates from zero to 25 m/s in 7. 5 s

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1 A 1000 kg sportscar accelerates from zero to 25 m/s in 7. 5 s
A 1000 kg sportscar accelerates from zero to 25 m/s in 7.5 s. What is the average power delivered by the automobile engine? 20.8 kW 30.3 kW 41.7 kW 52.4 kW 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

2 A bobsled makes a run down an ice track starting at 150 m vertical distance up the hill. If there is no friction, what is the velocity at the bottom of the hill? 27 m/s 36 m/s 45 m/s 54 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

3 A jet engine develops 105 N of thrust in moving an airplane forward at a speed of 900 km/hr. What is the power developed by the engine? 500 kW 1 MW 2.5 MW 5 MW 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

4 A speedboat requires 80 kW to move at a constant speed of 15 m/s
A speedboat requires 80 kW to move at a constant speed of 15 m/s. What is the resistive force of the water at this speed? 2667 N 5333 N 6500 N 7711 N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

5 A pole vaulter clears 6 m. With what velocity does he strike the mat in the landing area?
2.7 m/s 5.4 m/s 10.8 m/s 21.6 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

6 A parachutist of mass 50 kg jumps out of an airplane at a height of 1000 m. The parachute deploys, and she lands on the ground with a velocity of 5 m/s. How much energy was lost to air friction during this jump? 49,375 J 98,750 J 197,500 J 489,375 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

7 Water flows over a section of Niagara Falls at a rate of 1
Water flows over a section of Niagara Falls at a rate of 1.2 x 106 kg/s and falls 50 m. What is the power wasted by the waterfall? 588 MW 294 MW 147 MW 60 MW 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

8 A baseball outfielder throws a baseball of mass 0
A baseball outfielder throws a baseball of mass 0.15 kg at a speed of 40 m/s and initial angle of 30° . What is the kinetic energy of the baseball at the highest point of the trajectory? Ignore air friction. zero 30 J 90 J 120 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

9 A Russian weightlifter is able to lift 250 kg 2 m in 2 s
A Russian weightlifter is able to lift 250 kg 2 m in 2 s. What is his power output? 500 W 2.45 kW 4.9 kW 9.8 kW 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

10 A worker pushes a 500 N weight wheelbarrow up a ramp 50
A worker pushes a 500 N weight wheelbarrow up a ramp 50.0 m in length and inclined at 20° with the horizontal. What potential energy change does the wheelbarrow experience? 1500 J 3550 J 4275 J 8550 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

11 A worker pushes a 500 N weight wheelbarrow to the top of a 50
A worker pushes a 500 N weight wheelbarrow to the top of a 50.0 m ramp, inclined at 20° with the horizontal, and leaves it unattended. The wheelbarrow is accidentally bumped causing it to slide back down the ramp during which a 80 N frictional force acts on it over the 50.0 m. What is the wheelbarrow's kinetic energy at the bottom of the ramp? (g = 9.8 m/s2 ) 4550 J 6550 J 8150 J 13100 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

12 What is the kinetic energy of a 0
What is the kinetic energy of a kg baseball thrown at 40 m/s (90 mph)? 54 J 87 J 108 J 216 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

13 A 15. 0 kg crate, initially at rest, slides down a ramp 2
A 15.0 kg crate, initially at rest, slides down a ramp 2.0 m long and inclined at an angle of 20° with the horizontal. If there is no friction between ramp surface and crate, what is the kinetic energy of the crate at the bottom of the ramp? (g = 9.8 m/s2 ) 221 J 688 J 10.2 J 100 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

14 A worker pushes a wheelbarrow with a force of 50 N over a level distance of 5 m. If a frictional force of 43 N acts on the wheelbarrow in a direction opposite to that of the worker, what net work is done on the wheelbarrow? 250 J 215 J 35 J 10 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

15 cannot tell from the information given
If during a given physical process the only force acting on an object is friction, which of the following must be assumed in regard to the object's kinetic energy? decreases increases remains constant cannot tell from the information given 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

16 cannot tell from the information given
As an object is lowered into a deep hole in the surface of the earth, which of the following must be assumed in regard to its potential energy? increase decrease remain constant cannot tell from the information given 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

17 When an object is dropped from a tower, what is the effect of the air resistance as it falls?
does positive work increases the object's kinetic energy increases the object's potential energy None of these choices are valid. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

18 The unit of work, joule, is dimensionally the same as which of the following?
newton/second newton/kilogram newton-second newton-meter 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

19 The unit of power, watt, is dimensionally the same as which of the following?
joule-second joule/second joule-meter joule/meter 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

20 The rate at which work is done is equivalent to which of the following?
increase in potential energy thermal energy potential energy power 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

21 A worker pushes a wheelbarrow with a horizontal force of 50 N over a distance of 5 m. What work does the man do? 10 J 1250 J 250 J 55 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

22 A 40 N crate is pulled up a 5 m inclined plane at a constant velocity
A 40 N crate is pulled up a 5 m inclined plane at a constant velocity. If the plane is inclined at an angle of 37° to the horizontal and there exists a constant force of friction of 10 N between the crate and the surface, what is the net gain in potential energy by the crate in the process? 120 J -120 J 200 J -200 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

23 A 40 N crate starting at rest slides down a rough 6 m long ramp, inclined at 30° with the horizontal. The force of friction between crate and ramp is 6 N. What will be the velocity of the crate at the bottom of the incline? 1.6 m/s 3.3 m/s 4.5 m/s 6.4 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

24 Which of the following is an example of a non-conservative force?
gravity magnetism Both magnetism and gravity friction 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

25 Which of the following is that form of energy associated with an object's motion?
potential thermal bio-chemical kinetic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

26 Which of the following is that form of energy associated with an object's location in a conservative force field? potential thermal bio-chemical kinetic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

27 A 50 N crate is pulled up a 5 m inclined plane by a worker at constant velocity. If the plane is inclined at an angle of 37° to the horizontal and there exists a constant force of 10 N between the crate and the surface, what is the force applied by the worker? zero 20 N 30 N 40 N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

28 A small wagon moving at constant velocity carries a 200 N crate 10 m across a level surface. What is the net work done in the process? zero 1/20 J 20 J 2000 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

29 The quantity of work equal to one joule is also equivalent to which of the following?
watt watt/s watt x s watt/s2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

30 A 3 kg object starting at rest falls to the ground from a height of 10 m. Just before hitting the earth what will be its kinetic energy? (g = 9.8 m/s2 and assume air resistance is negligible.) 98 J 0.98 J 29.4 J 294 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

31 An arrow, shot straight up from a crossbow has an initial velocity of 50 m/s. Ignore energy lost to air friction. How high will the arrow rise? 49 m 62.4 m 98 m 127.5 m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

32 What is the minimum amount of energy required for an 80-kg climber carrying a 20-kg pack to climb Mt. Everest, 8850 m high? 8.67 mJ 4.16 mJ 2.47 mJ 1.00 mJ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

33 A professional skier reaches a speed of 56 m/s on a 30° ski slope
A professional skier reaches a speed of 56 m/s on a 30° ski slope. Ignoring friction, what is the minimum distance along the slope the skier would have to travel, starting from rest? 110 m 160 m 320 m 640 m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

34 She stops before she reaches the bottom.
A girl and her bicycle have a total mass of 40 kg. At the top of the hill her speed is 5 m/s. The hill is 10 m high and 100 m long. If the force of friction as she rides down the hill is 20 N, what is her speed at the bottom? 5 m/s 10 m/s 11 m/s She stops before she reaches the bottom. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

35 Old Faithful geyser in Yellowstone Park shoots water more or less hourly to a height of 40 meters. With what velocity does the water leave the ground? 7.0 m/s 14.0 m/s 19.8 m/s 28.0 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

36 An 80,000 kg airliner is flying at 900 kilometers/hour at a height of 10 kilometers. What is its total energy (kinetic + potential)? 250 MJ 478 MJ 773 MJ 10,340 MJ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

37 A 1200 kg automobile moving at 25 m/s has the brakes applied with a deceleration of 8 m/s2 . How far does the car travel before it stops? 39 m 47 m 55 m 63 m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

38 A girl and her bicycle have a total mass of 40 kg
A girl and her bicycle have a total mass of 40 kg. At the top of the hill her speed is 5 m/s and her speed doubles as she rides down the hill. The hill is 10 m high and 100 m long. How much kinetic energy and potential energy is lost to friction? 2420 J 1500 J 2000 J 3920 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

39 A 60 g golf ball is dropped from a height of 2 m and rebounds to 1.5 m. How much energy is lost?
0.29 J 0.5 J 0.88 J 1 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

40 It did not lose kinetic energy.
A golf ball hits a wall and bounces back at 3/4 the original speed. What part of the original kinetic energy of the ball did it lose in the collision? 1/4 3/8 7/16 It did not lose kinetic energy. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

41 If both the mass and the velocity of a ball are tripled, the kinetic energy is increased by a factor of 3 6 9 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

42 A 2 kg ball which originally has zero kinetic and potential energy is dropped into a well which is 10 m deep. Just before the ball hits the bottom, the sum of its kinetic and potential energy is 196 J -196 J 392 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

43 A 2 kg ball which originally has zero potential and kinetic energy is dropped into a well which is 10 m deep. After the ball comes to a stop in the mud, the sum of its potential and kinetic energy is 196 J -196 J 392 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

44 A hill is 100 m long and makes an angle of 12° with the horizontal
A hill is 100 m long and makes an angle of 12° with the horizontal. As a 50 kg jogger runs up the hill, how much work does gravity do on the jogger? 49,000 J 10,000 J -10,000 J zero 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

45 The block that went straight down. The block that went down the ramp.
Two blocks are released from the top of a building. One falls straight down while the other slides down a smooth ramp. If all friction is ignored, which one is moving faster when it reaches the bottom? The block that went straight down. The block that went down the ramp. They both will have the same speed. Insufficient information to work the problem. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

46 A simple pendulum, 2.0 m in length, is released by a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, to what maximum angle will it move in the second half of its swing? (g = 9.8 m/s2 ) 37° 30° 27° 21° 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

47 An automobile delivers 30 hp to its wheels when moving at a constant speed of 22 m/s. What is the resistance force on the automobile at this speed? (1 hp = 746 watts) 18,600 N 410,000 N 1,020 N 848 N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

48 I use a rope to swing a 10 kg weight around my head
I use a rope to swing a 10 kg weight around my head. The rope is 2 m long and the tension in the rope is 20 N. In half a revolution how much work is done by the rope on the weight? 40 J 126 J 251 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

49 The work done by static friction is always
positive negative along the surface zero 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

50 A simple pendulum, 2.0 m in length, is released with a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, what is its speed at the bottom of the swing? (g = 9.8 m/s2 ) 2.3 m/s 2.6 m/s 2.0 m/s 0.5 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

51 A horizontal force of 200 N is applied to a 55 kg cart across a 10 m level surface. If the cart accelerates at 2.0 m/s2 then what force of friction acts to retard the motion of the cart? 110 N 90 N 80 N 70 N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

52 A baseball catcher puts on an exhibition by catching a 0
A baseball catcher puts on an exhibition by catching a 0.15 kg ball dropped from a helicopter at a height of 101 m. What is the speed of the ball just before it hits the catcher's glove 1.0 m above the ground? (g = 9.8 m/s2 and ignore air resistance) 44.3 m/s 38.0 m/s 31.3 m/s 22.2 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

53 A baseball catcher puts on an exhibition by catching a 0
A baseball catcher puts on an exhibition by catching a 0.15 kg ball dropped from a helicopter at a height of 100 m above the catcher. If the catcher "gives" with the ball for a distance of 0.75 m while catching it, what average force is exerted on the mitt by the ball? (g = 9.8 m/s2 ) 78 N 119 N 196 N 392 N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

54 A horizontal force of 200 N is applied to move a 55 kg cart across a 10 m level surface. What work is done by the 200 N force? 4000 J 5400 J 2000 J 2700 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

55 A simple pendulum, 1.0 m in length, is released from rest when the support string is at an angle of 35° from the vertical. What is the speed of the suspended mass at the bottom of the swing? (ignore air resistance, g = 9.8 m/s2 ) 0.67 m/s 0.94 m/s 1.33 m/s 1.88 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

56 A pile driver drives a post into the ground
A pile driver drives a post into the ground. The mass of the pile driver is 2500 kg and it is dropped through a height of 8 m on each stroke. If the resisting force of the ground is 4 x 106 N, how far is the post driven in on each stroke? 4.9 cm 9.8 cm 16.0 cm 49.0 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

57 A 2000-kg ore car rolls 50 meters down a frictionless 10° incline
A 2000-kg ore car rolls 50 meters down a frictionless 10° incline. If there is a horizontal spring at the end of the incline, what spring constant is required to stop the ore car in a distance of 1 meter? 340.3 kN/m 680.7 kN/m 980.0 kN/m kN/m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

58 An amount of work equal to 1 J is required to compress the spring in a spring-gun. To what height can this "gun" shoot a 20-gram marble? 5.1 m 10.2 m 15.3 m 20.4 m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

59 A 60-kg woman runs up a flight of stairs having a rise of 4 meters in a time of 4.2 seconds. What average power did she supply? 380 W 560 W 616 W 672 W 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

60 A 15. 0 kg crate, initially at rest, slides down a ramp 2
A 15.0 kg crate, initially at rest, slides down a ramp 2.0 m long and inclined at an angle of 20° with the horizontal. If there is no friction between the ramp surface and crate, what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s2 ) 6.1 m/s 3.7 m/s 10.7 m/s 8.3 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50


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