Class 9 Practice Level 2 – Work and Energy set – 2

Total questions: 25

A force of 80 N is applied to move a box 5 meters across a floor. If the force is applied at an angle of 45 degrees to the horizontal, what is the work done by the force?

Topic: Work

200 J

283 J

400 J

566 J

None

A 1200 kg car is moving with a speed of 15 m/s. What is its kinetic energy?

Topic: Energy

135,000 J

180,000 J

225,000 J

270,000 J

None

If a motor raises 200 liters of water per minute to a height of 15 meters, what is the power of the motor? (Take g=10 m/$ \displaystyle {{s}^{{2}}}$; 1 liter of water = 1 kg)

Topic: Power

500 W

750 W

1000 W

1250 W

None

An object is lifted vertically 8 meters by a force of 120 N. What is the work done against gravity?

Topic: Work

480 J

720 J

960 J

1200 J

None

A pendulum bob of mass 0.8 kg is raised to a height of 0.4 meters. What is its potential energy at this height?$ \displaystyle \left( {\text{Take }g=10m/{{s}^{2}}} \right)$

Topic: Energy

1.6 J

2.4 J

3.2 J

4.8 J

None

A machine does 6000 joules of work in 30 seconds. What is its power output?

Topic: Power

150 W

200 W

250 W

300 W

None

A person pulls a cart with a force of 60 N over a distance of 15 meters in 10 seconds. What is the power exerted by the person?

Topic: Work

60 W

90 W

120 W

150 W

None

A ball of mass 0.5 kg is moving with a velocity of 8 m/s. What is its kinetic energy?

Topic: Energy

8 J

16 J

20 J

32 J

None

If a motor does 4500 J of work in 15 seconds, what is its power output?

Topic: Power

200 W

250 W

300 W

400 W

None

10.

A crane lifts a load of 750 kg to a height of 12 meters. How much work is done?$ \displaystyle \left( {\text{Take }g=10m/{{s}^{2}}} \right)$

Topic: Work

7500 J

9000 J

75,000 J

90,000 J

None

11.

A spring with a spring constant of 300 N/m is compressed by 0.1 meters. What is the potential energy stored in the spring?

Topic: Energy

1.5 J

3 J

4.5 J

6 J

None

12.

A person does 500 J of work by lifting a box in 8 seconds. What is the power developed by the person?

Topic: Power

50 W

62.5 W

75 W

87.5 W

None

13.

A force of 40 N is applied to move a box 6 meters. The force is applied at an angle of 30 degrees to the direction of motion. What is the work done?

Topic: Energy

100 J

120 J

150 J

200 J

None

14.

A person pulls a sled with a force of 50 N at an angle of 60 degrees to the horizontal. If the sled is pulled a distance of 6 meters, what is the work done?

Topic: Work

150 J

180 J

200 J

240 J

None

15.

A 4 kg object is moving with a velocity of 12 m/s. What is its kinetic energy?

Topic: Energy

72 J

144 J

216 J

288 J

None

16.

A person does 720 J of work in 3 minutes. What is the power developed by the person in watts?

Topic: Power

2 W

3 W

4 W

5 W

None

17.

An electric motor lifts a 12 kg object to a height of 10 meters in 4 seconds. What is the power output of the motor?

Topic: Work

250 W

300 W

400 W

500 W

None

18.

A stone of mass 0.4 kg is thrown vertically upward with an initial velocity of 20 m/s. What is its kinetic energy at the highest point?

Topic: Energy

0 J

40 J

80 J

160 J

None

19.

An electric pump does 12,000 J of work in pumping water in 80 seconds. What is the power of the pump?

Topic: Power

100 W

120 W

150 W

200 W

None

20.

If a person pushes a box with a force of 25 N at an angle of 45 degrees to the horizontal and moves it 8 meters, what is the work done?

Topic: Work

100 J

125 J

140 J

150 J

None

21.

A 2 kg mass is lifted to a height of 3 meters. What is the potential energy gained by the mass?$ \displaystyle (\mathbf{Take}\text{ }\mathbf{g}=\mathbf{10}\,\mathbf{m}/\mathbf{s^2})$

Topic: Energy

20 J

30 J

50 J

60 J

None

22.

If an electric motor does 5400 J of work in 45 seconds, what is its power output?

Topic: Power

100 W

120 W

140 W

150 W

None

23.

A machine does 9000 J of work in moving an object 15 meters. What is the force exerted by the machine?

Topic: Work

300 N

450 N

600 N

750 N

None

24.

A 3 kg object is dropped from a height of 5 meters. What is its kinetic energy just before it hits the ground?$ \displaystyle (\mathbf{Take}\text{ }\mathbf{g}=\mathbf{10}\,\mathbf{m}/\mathbf{s^2})$

Topic: Energy

50 J

100 J

150 J

200 J

None

25.

A person pulls a sled with a force of 50 N at an angle of 60 degrees to the horizontal. If the sled is pulled a distance of 6 meters, what is the work done?

Topic: Work

150 J

180 J

200 J

240 J

None

1 out of 25

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Class 9 Practice Level 2 – Work and Energy set – 2

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