answer the questions (Mechanics) multiple choice

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Question 1

Topic: Newton’s 2nd Law 47) A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes to rest. It takes

the block 2 seconds to stop. The stopping force acting on the block is about: (hint use linear motion formula to find deceleration)

5 N.

50 N.

25 N.

10 N.

Question 2

Suppose you’re on a Ferris wheel at a carnival, seated 5 m from the Ferris wheel’s axis. If you make a complete rotation each minute, your linear speed

is? (think distance traveled per time period and find the distance from considering a circle)

62.8 m/min.

100 m/min.

31.4 m/min.

10 m/min.

Not enough information is given.

Question 3

Topic: Newton’s 2nd Law 22) A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second. What is the mass of the car?

1000 kg

500 kg

3000 kg

1500 kg

Question 4

(C03TBq 17) A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s?

10 m

100 m

40 m

2m

200 m

Question 5

Topic: Newton’s 2nd Law 7) The force of friction on a sliding object is 10 newtons. The applied force needed to maintain a constant velocity is

10 N.

none listed correct

more than 10 N.

less than 10 N.

Question 6

(C07TBq 34) Using 1000 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed to do this job was

20,000 W.

50 W.

1000 W.

20 W.

100 W.

Question 7

Topic: Newton’s 2nd Law 46) A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree. What is the deceleration in meters per

second per second of the car?

110

800

220

880

Question 8

(C03TBq 12) If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is

6 km/h/s.

10 km/h/s.

3 km/h/s.

600 km/h/s.

60 km/h/s.

Question 9

A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat

reaches the east bank: (Hint: use Vectors)

100 m farther north than where it started.

due east of where it started.

141 m farther south than where it started.

no idea

100 m farther south than where it started.

Question 10

Topic: Newton’s 2nd Law 34) A 10-N block and a 1-N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we

would have to push with

10 times as much force on the heavier block.

1/10 as much force on the heavier block.

equal forces on each block.

10 squared or 100 times as much force on the heavier block.

Question 11

A bullet is fired horizontally with an initial velocity of 300 m/s from a tower 20 m high. If air resistance is negligible, the horizontal distance the bullet

travels before hitting the ground is about (hint: determine the time using height and 10m/s2 for g). (Hint; see slides for projectiles)

200 m.

400 m.

600 m

300 m.

500 m.

Question 12

A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the ball land

20 m down range. What is the player’s pitching speed? (Hint: see slides for projectiles)

about 10 m/s

none of these

about 5 m/s

about 20 m/s

about 25 m/s

Question 13

A river 100 m wide flows due south at 1 m/s. A boat that goes for 50 seconds from west bank to land at a point due straight east of its starting point, the

boat must be going? (Hint: use Vectors)

1 m/s north.

1.41 m/s northeast.

141 m/s east.

nowhere it can’t be done.

2.24 m/s northeast

Question 14

(C07TBq 29 mo A TV set is pushed a distance of 1 m with a force of 20 N. How much work is done on the set?

40 J

2J

20 J

10 J

800 J

Question 15

An airplane travels at 141 km/h exactly toward the northeast. What is its component of velocity due north? (use coordinate system

and Pythagoras or cosine of the angles)

100 km/h

110 km/h

200 km/h

141 km/h

41 km/h

Question 16

(C03TBq 9) If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, then its

speed reading would increase each second by

20 m/s.

40 m/s.

depends on its initial speed

30 m/s.

10 m/s.

Question 17

Topic: Newton’s 2nd Law 41) A 1-kg rock that weighs 9.8 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it

when it is half way to the top of its path is

None of these

less than 9.8 N.

9.8 N.

more than 9.8 N.

Question 18

(C03TBq2) A horse gallops a distance of 10 kilometers in a time of 30 minutes. Its average speed is

0

40 km/h.

30 km/h.

15 km/h.

20 km/h.

Question 19

(C07TBq 30 mo It takes 40 J to push a large box 10 m across a floor. Assuming the push is in the same direction as the move, what is the magnitude of the

force on the box?

160 N

40 N

4N

none of these

10 N

Question 20

(C03TBq 25) At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately

infinity

40 m/s.

55 m/s.

50 m/s.

60 m/s.

Question 21

(C07TBq 16 mo A bow is drawn so that it has 100 J of potential energy. When fired, the arrow will ideally have a kinetic energy that is

50 J

impossible to predict without additional information

less than 40 J.

more than 40 J.

100 J.

Question 22

(C03TBq 10) Twelve seconds after starting from rest, an object falling freely will have a speed of

100 m/s.

more than 100 m/s.

10 m/s.

50 m/s.

0

Question 23

(C03TBq 8) If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about

15 m/s.

a variable amount.

5 m/s.

10 m/s.

depends on its initial speed

Question 24

(C07TBq 7) The power required to exert 2 N force, over a distance of 2 m in 2 second is

3 W.

2 W.

1 W.

1/3 W.

none of these

Question 25

Topic: Newton’s 2nd Law 53) What horizontally-applied force will accelerate a 400-kg crate at 1 m/s/s across a factory floor against a friction force half its

weight? ( find weight mass correlation and use it with gravity acceleration)

600 N

1600 N

2400 N

2000 N

Question 26

(C07TBq 8 mod) Do 100 J of work in 20 s and your power output is

1/2 W

5 W.

50 W.

4 W.

5,000 W.

Question 27

Topic: Newton’s 2nd Law 49) If you are driving at 20 m/s and slam on your brakes and skid at 0.5 g to a full stop, the skidding time in seconds is (hint:

deceleration here is in tines gravity acceleration )

about 3.

about 5.

about 6.

about 4.

Question 28

Topic: Newton’s 2nd Law 21) A car has a mass of 1000 kg and accelerates at 2 meters per second per second. What is the magnitude of the net force

exerted on the car?

2000 N

1500 N

500 N

1000 N

Question 29

(C03TBq 15 mod) It takes 10 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

about 180 m

about 120 m

more than 200 m

0

about 60 m

Question 30

(C03TBq 42) Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car’s acceleration in meters per second per second?

10

0.25

4

40

2.8

Question 31

(C07TBq 11 mo A 500-kg car and a 2000-kg car are hoisted the same distance. Raising the more massive car requires

as much work.

less work.

twice as much work.

more than four times as much work.

four times as much work.

Question 32

Topic: Newton’s 2nd Law 42) A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the stone when it is

halfway to the top of its path is about

5 N.

1 N.

1/2 N.

10 N.

Question 33

An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of? (Hint: use Vectors)

100 km/h.

400 km/h

200 km/h.

0 km/h.

141 km/h.

Question 34

A river 100 m wide flows due south. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat crosses

in? (Hint: use Vectors and linear motion formulas)

240 s

141 s.

200 s.

50 s.

100 s.

Question 35

(C07TBq 37) A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has

8 times the KE.

16 times the KE.

12 times the KE.

0

4 times the KE.

Question 36

Topic: Newton’s 2nd Law 50) A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds.

How far does the automobile travel during that time? (use linear motion equitations, the mass is not needed here!)

100 m

400 m

300 m

200 m

Question 37

Throw an object upward at a 45 degree angle. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 second, it

is? (Hint: draw it in a coordinate system, use Vectors and consider just the vertical component where you apply gravity as in free fall)

about 10 m below the straight line.

about 5 m below the straight line.

about 25 m below the straight line

about 15 m below the straight line.

about 35 m below the straight line

Question 38

(C07TBq 40) A machine puts out 100 Watts of power for every 1000 Watts put into it. The efficiency of the machine is

110%.

none of these

90%.

50%.

10%.

Question 39

Topic: Newton’s 2nd Law 6) An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The

magnitude of the resultant force on the object is

5 N.

150 N.

0 N.

25 N.

Question 40

Topic: Newton’s 2nd Law 51) A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the

brakes were applied was? ( start with Newton 2 then use definition for acceleration)

1.2 m/s.

45 m/s.

15 m/s.

30 m/s.

Question 41

(C03TBq 40) A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of

30 m/s?

15 seconds

60 seconds

30 seconds

2 seconds

none of these

Question 42

(C03TBq 21) If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about

4 m/s.

6 m/s.

0

3 m/s.

2 m/s.

Question 43

A river 100 m wide flows due south. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. Relative to the Earth,

the boat travels? (Hint: use Vectors)

241 m.

200 m.

nowhere.

141 m.

100 m.

Question 44

(C07TBq 45) Consider a hydraulic press. When the input piston is depressed 20 cm, the output piston is raised 1 cm. On the same press, an input force of 1

N can lift a load of

15 N.

20 N.

All of the above are correct.

1 N.

10 N.

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