A 5 kg object is dropped from a height of 20 m. What is the total mechanical ene

Practice Questions

Q1
A 5 kg object is dropped from a height of 20 m. What is the total mechanical energy just before it hits the ground?
  1. 0 J
  2. 100 J
  3. 200 J
  4. 500 J

Questions & Step-by-Step Solutions

A 5 kg object is dropped from a height of 20 m. What is the total mechanical energy just before it hits the ground?
  • Step 1: Identify the mass of the object. In this case, the mass (m) is 5 kg.
  • Step 2: Identify the height from which the object is dropped. The height (h) is 20 m.
  • Step 3: Use the formula for gravitational potential energy (PE), which is PE = mgh.
  • Step 4: Substitute the values into the formula: PE = 5 kg * 9.8 m/s² * 20 m.
  • Step 5: Calculate the potential energy: PE = 5 * 9.8 * 20 = 980 J.
  • Step 6: Understand that total mechanical energy is conserved, meaning it remains the same throughout the fall.
  • Step 7: Conclude that just before the object hits the ground, the total mechanical energy is still 980 J.
  • Potential Energy (PE) – The energy an object possesses due to its position in a gravitational field, calculated as PE = mgh.
  • Conservation of Mechanical Energy – The principle stating that the total mechanical energy (potential + kinetic) in a closed system remains constant if only conservative forces are acting.
Soulshift Feedback ×

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

Not likely Very likely