Speed of particle increases by 20%.How many percent its kinetic energy increases

Asked by lovemaan5500 | 26th Dec, 2017, 11:23: AM

Expert Answer:

let the initial velocity be V
 
20 % increase will be  V + 20% of V
 
= 1.2V
 
KEi = 1/2 m v2
 
KEf = 1/2 m (1.2v)2
 
     = 1.44 x 1/2 m v2
 
 
 
increase in KE= KEf  -  KEi  = 1.44 x 1/2 m v2  -  1/2x m v= 0.44 x 1/2 m v2
 

 
 
percent increase in kinetic energy 
 
begin mathsize 20px style equals fraction numerator i n c r e a s e space i n space K E over denominator K E subscript i end fraction space equals space fraction numerator 0.44 space x 1 divided by 2 space m space v squared over denominator 1 divided by 2 space m space v squared end fraction space equals space 0.44 space end style
 
Answer is 44 %

Answered by Gajendra | 27th Dec, 2017, 04:49: PM