Work Energy And Power Question 245

Question: When a body is projected vertically up from the ground with certain velocity, its potential energy and kinetic energy at a point A are in the ratio 2 : 3. If the same body is projected with double the previous velocity, then at the same point A the ratio of its potential energy to kinetic energy is

Options:

A) 9 : 1

B) 2 : 9

C) 1 : 9

D) 9 : 2

Show Answer

Answer:

Correct Answer: C

Solution:

[c] Let E be the total energy then

P.EK.E=mghEmgh=23E=52mgh

When velocity is double then inital energy becomes 4E.

So, mgh4Emgh=NL=mgh10mghmgh

On solving we get P.EK.E=19 .



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