Physics · The potential energy of a spring, conservation of mechanical energy, conservative and non-conservative forces

A body is dropped from a certain height from the ground. When it is halfway down

A body is dropped from a certain height from the ground. When it is halfway down, it possess,

  • A. Only K.E.
  • B. Both K.E. and P.E.
  • C. only P.E.
  • D. zero energy

Step-by-step solution

When a body is dropped, it has initial potential energy (P.E. = mgh) and zero kinetic energy (K.E.). As it falls, its height decreases, so P.E. decreases while K.E. increases due to conservation of mechanical energy. At halfway down, height = h/2, so P.E. = mgh/2. Since total energy is conserved, K.E. = total energy - P.E. = mgh - mgh/2 = mgh/2. Thus, the body possesses both K.E. and P.E.
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