JAMB and WAEC Physics questions: Work, energy and power

29 questions with answers and explanations. Tap an option to check yourself.

1. Question 21· Work, energy and power· WAEC

   The kinetic energy of a 4 kg body moving at 3 m/s is

   • A12 J
   • B18 J
   • C36 J
   • D6 J

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   Explanation and discussion

2. Question 22· Work, energy and power· WAEC

   When a body falls freely, its

   • Akinetic energy changes into potential energy
   • Bpotential energy changes into kinetic energy
   • Ctotal energy increases
   • Dmass increases

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   Explanation and discussion

3. Question 23· Work, energy and power· JAMB

   A 2 kg body moving at 3 m/s has kinetic energy of:

   • A9 J
   • B6 J
   • C3 J
   • D18 J

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   Explanation and discussion

4. Question 24· Work, energy and power· WAEC

   A boy lifts a 25 kg bag through a height of 2 m. How much work does he do? [g = 10 m/s²]

   • A250 J
   • B50 J
   • C500 J
   • D5000 J

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5. Question 25· Work, energy and power· JAMB

   A car of mass 1000 kg speeds up from 10 m/s to 20 m/s. Find the work done on it.

   • A1.5 × 10⁵ J
   • B5 × 10⁴ J
   • C2 × 10⁵ J
   • D1 × 10⁴ J

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6. Question 26· Work, energy and power· WAEC

   In a dynamo the main energy change is from

   • Aelectrical to mechanical
   • Bmechanical to electrical
   • Cchemical to electrical
   • Dheat to electrical

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7. Question 27· Work, energy and power· JAMB

   For a swinging pendulum, the kinetic energy is greatest at the

   • Apoint of release
   • Bhighest point of the swing
   • Clowest point of the swing
   • Dmiddle of the string

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   Explanation and discussion

8. Question 28· Work, energy and power· WAEC

   Find the kinetic energy of a 2 kg mass moving at 6 m/s.

   • A18 J
   • B12 J
   • C72 J
   • D36 J

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   Explanation and discussion

9. Question 29· Work, energy and power· JAMB

   A 5 kg mass is raised through 4 m. Find its gain in potential energy.

   • A20 J
   • B200 J
   • C2000 J
   • D9 J

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   Explanation and discussion