energy of a particle is 5J if unit of length and time are double and unit of mass is - Physics - Units And Measurements

Question

energy of a particle is 5J if unit of length and time are double
and unit of mass is halved then numerical value of energy in this
new system will be 5n Value of n is

Jyoti Pant · Accepted Answer

Original unit of energy, E=[ML2T-2]Now according to question,L'=2L, T'=2T and M'=M2Then,E'=[M2(2L)2(2T)-2]=[ML2T-22]=12EThus, 12×5=2
5 J=5nSo, n=0 5

energy of a particle is 5J. if unit of length and time are double and unit of mass is halved then numerical value of energy in this new system will be 5n. Value of n is