A stone of mass 1kg is dropped from a height of 10m above...
A stone of mass 1kg is dropped from a height of 10m above the ground and falls freely under gravity. Its kinetic energy 5m above the ground is then equal to
its kinetic energy on the ground
twice its initial potential energy
its initial potential energy
half its initial potential energy
Correct answer is D
At the height of 10m, its total energy is potential, given by P.E. = mgh = 1 x 10 x 10 = 100J.
But as the stone descends, its potential energy decreases, while its kinetic energy increases.
Half way during the fall, (h = 5m), its P.E. = 50J, and consequently, its K.E. should be 50J, such that from the principle of conservation of energy, the total energy of the stone at any instant should be conserved.
The plane mirrors in a kaleidoscope are usually placed ...
An object of mass 5.0 kg moves with a velocity of 10ms-1. Calculate its momentum....
Steel bars each of length 3m at 28°C are to be used for constructing a rail line. If the linear ...
What is the least possible error encountered when taking measurement with a meter rule? ...
Which of the following is not a mechanical wave?...
Which of the current-voltage characteristics shown below is that exhibited an ohmic conductor? ...