Energy Work and Power Practice Questions
NECO (Nigeria) · NECO Physics · 140 free MCQs with instant results and detailed explanations.
140
Total
43
Easy
71
Medium
26
Hard
Start Practicing Energy Work and Power
Take a timed quiz or customize your practice session
Sample Questions from Energy Work and Power
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the formula for calculating work done when a force is applied to move an object?
A.
Work = Force ร Distance ร cos(ฮธ)
B.
Work = Force + Distance
C.
Work = Force / Distance
D.
Work = Force - Distance
Show Answer & Explanation
Correct Answer: A
The correct formula for work done (W) is W = F ร d ร cos(ฮธ), where F is the force applied, d is the distance moved in the direction of the force, and ฮธ is the angle between the force and the direction of motion. This accounts for the directionality of force.
Q2
Easy
If a car does 4000 joules of work in moving a distance of 20 meters, what is the average force exerted?
A.
200 N
B.
100 N
C.
50 N
D.
250 N
Show Answer & Explanation
Correct Answer: A
To find the average force, we use the formula: Work = Force ร Distance. Rearranging gives us Force = Work / Distance. Plugging in the values gives us 4000 J / 20 m = 200 N.
Q3
Easy
A 5 kg object is lifted 2 meters vertically. How much gravitational potential energy does it gain?
A.
98 J
B.
10 J
C.
20 J
D.
40 J
Show Answer & Explanation
Correct Answer: A
Gravitational potential energy (PE) can be calculated using the formula: PE = mgh, where m is mass (5 kg), g is acceleration due to gravity (approximately 9.8 m/sยฒ), and h is height (2 m). Thus, PE = 5 kg ร 9.8 m/sยฒ ร 2 m = 98 J.
Q4
Medium
An object is moving with a constant speed. If the net work done on it is zero, what can be inferred about its motion?
A.
It is accelerating.
B.
It is decelerating.
C.
It is moving at constant velocity.
D.
It is changing direction.
Show Answer & Explanation
Correct Answer: C
If the net work done on the object is zero, then there is no change in its kinetic energy, implying it maintains a constant velocity.
Q5
Medium
A spring has a spring constant of 300 N/m. If it is compressed by 0.2 m, what is the potential energy stored in the spring?
A.
6 J
B.
12 J
C.
3 J
D.
1 J
Show Answer & Explanation
Correct Answer: A
Potential energy in a spring is given by the formula PE = 0.5 * k * xยฒ. Here, PE = 0.5 * 300 N/m * (0.2 m)ยฒ = 6 J.
Q6
Medium
A box of mass 10 kg is lifted to a height of 5 meters. What is the work done against gravity? (Use g = 9.8 m/sยฒ)
A.
490 J
B.
98 J
C.
500 J
D.
250 J
Show Answer & Explanation
Correct Answer: A
Work done is calculated using the formula: Work = mass ร gravity ร height. Here, Work = 10 kg ร 9.8 m/sยฒ ร 5 m = 490 J.
Q7
Medium
A cyclist does 200 J of work to overcome friction and travel 50 meters. What is the efficiency of the cyclist if the input energy was 400 J?
A.
50%
B.
40%
C.
60%
D.
70%
Show Answer & Explanation
Correct Answer: A
Efficiency is calculated using the formula: Efficiency = (Useful Work Output / Total Energy Input) ร 100%. Here, Efficiency = (200 J / 400 J) ร 100% = 50%.
Q8
Hard
A 5 kg object is lifted to a height of 10 m. Calculate the work done against gravity. (Take g = 10 m/sยฒ)
A.
500 J
B.
250 J
C.
100 J
D.
50 J
Show Answer & Explanation
Correct Answer: A
The work done against gravity is calculated using the formula W = mgh, where m is mass, g is acceleration due to gravity, and h is height. For this question, W = 5 kg * 10 m/sยฒ * 10 m = 500 J.
Q9
Hard
A machine does 12,000 J of work in 4 minutes. What is the power output of the machine in watts?
A.
50 W
B.
30 W
C.
40 W
D.
60 W
Show Answer & Explanation
Correct Answer: A
Power is defined as the rate of doing work, calculated using the formula P = W/t, where W is work done and t is time in seconds. Here, the work done is 12,000 J and the time is 4 minutes (which is 240 seconds). Thus, P = 12,000 J / 240 s = 50 W.
Q10
Hard
A 50 kg block is lifted to a height of 10 meters. Calculate the work done against gravity. (Take g = 9.8 m/sยฒ)
A.
490 J
B.
980 J
C.
4900 J
D.
9800 J
Show Answer & Explanation
Correct Answer: C
The work done (W) against gravity is calculated using the formula W = m * g * h. Here, m = 50 kg, g = 9.8 m/sยฒ, and h = 10 m. Therefore, W = 50 * 9.8 * 10 = 4900 J, which is option C.
Showing 10 of 140 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 140 Questions →Other NECO (Nigeria) Subjects
Energy Work and Power โ NECO (Nigeria) NECO Physics Practice Questions Online
This page contains 140 practice MCQs for the chapter Energy Work and Power in NECO (Nigeria) NECO Physics. The questions are organized by difficulty โ 43 easy, 71 medium, 26 hard โ so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.