AP EAMCET201823 Apr 2018Morning ShiftPhysicsWork, Power and EnergyActual
A particle is released from a height H . At a certain height, its kinetic energy is half of its potential energy with reference to the surface of the earth. Height and speed of the particle at that instant are respectively
Options
- AH 3 , 2 g H 3
- BH 3 , 2 g H 3
- C2 H 3 , 2 g H
- D2 H 3 , 2 g H 3
Correct answer
D. 2 H 3 , 2 g H 3
Step-by-step solution
Total mechanical energy of particle, i.e. Given, KE = 1 2 PE i.e. aligned & KE PE = 1 2 & PE =2 KE aligned or Substituting in this Eq. (i), we get aligned PE + KE & =m g H 2 KE + KE & =m g H 3 KE & =m g H KE & = m g H 3 PE & = 2 3 m g H aligned Similarly, So, height from ground at that instant, h= 2 H 3 So, speed of particle, v= 2 g h = 2 g H / 3