if the error in the measurement of momentum of a particle is 10% and mass is known exactly,the permissible error in the determination of kinetic energy is

Here , K.E- 1/2mv^2Mass is known exactly but there is always a minimum error in any calculation so, Here we let the minimum in mass =1% Now, ∆K/K=∆ M/M +2∆V/V = 1% + 2(10%) = 1% + 20% = 21%