Give one example of each of the following: Small mass but high kinetic energy

cbse
cbse-class-9-science
work-and-energy

#1
  1. Give one example of each of the following:
  • Small mass but high kinetic energy
  • Large mass but low kinetic energy
  1. Prove mathematically that the total mechanical energy of a freely falling body in air is conserved.

Answer:

  • A cricket/hockey ball which has been hit hard and is travelling fast.
  • A shot put thrown by an athlete
  1. (b) Let the body of mass m at height h above the ground starting from rest, be falling freely.
    Total energy of the body at height h
    mgh (PE) + 0 (KE) = mgh
    After the body has fallen freely through a distance x (say),
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