A person lifts a box of mass 10 kg to a height of 2 m in 4 seconds. What is the

Practice Questions

Q1
A person lifts a box of mass 10 kg to a height of 2 m in 4 seconds. What is the power exerted by the person?
  1. 50 W
  2. 25 W
  3. 100 W
  4. 75 W

Questions & Step-by-Step Solutions

A person lifts a box of mass 10 kg to a height of 2 m in 4 seconds. What is the power exerted by the person?
  • Step 1: Identify the mass of the box, which is 10 kg.
  • Step 2: Identify the height the box is lifted to, which is 2 m.
  • Step 3: Use the formula for gravitational force, which is approximately 9.8 m/s².
  • Step 4: Calculate the work done (W) using the formula W = mgh, where m is mass, g is gravitational force, and h is height.
  • Step 5: Substitute the values into the formula: W = 10 kg * 9.8 m/s² * 2 m.
  • Step 6: Calculate the work done: W = 10 * 9.8 * 2 = 196 J (joules).
  • Step 7: Identify the time taken to lift the box, which is 4 seconds.
  • Step 8: Use the formula for power (P), which is P = W/t, where W is work done and t is time.
  • Step 9: Substitute the values into the power formula: P = 196 J / 4 s.
  • Step 10: Calculate the power: P = 49 W (watts).
  • Step 11: Round the power to approximately 50 W if needed.
  • Work and Energy – Understanding the calculation of work done against gravitational force using the formula W = mgh.
  • Power – Calculating power as the rate of doing work, using the formula P = W/t.
  • Units of Measurement – Recognizing and converting units of work (Joules) and power (Watts).
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely