KCET2011PhysicsWork, Power and Energy
A body of mass 5 ~kg is thrown vertically up with a kinetic energy of 490 ~J . The height at which the kinetic energy of the body becomes half of the original value is (acceleration due to gravity =9.8 ~ms ⁻² )
Options
- A5 ~m
- B2.5 ~m
- C10 ~m
- D12.5 ~m
Correct answer
A. 5 ~m
Step-by-step solution
Given, m=5 ~kg and KE =490 ~J By the law of conservation of energy aligned 1 2 m u² &= 1 2 m v²+m g h 490 &=245+5 9.8 h h &= 490-245 5 9.8 h &= 245 49 &=5 ~m aligned