Question

Two charged particles of mass m and 2m have charges +2q and +q respectively. They are kept in a uniform electric field far away from each other and then allowed to move for some time t. Find the ratio of their kinetic energy.

Answer 1

Dear Student,

◆ Answer -

E1 : E2 = 8 : 1

● Explaination -

Velocity of mass m after time t is -

v1 = 2qε/m × t

v1 = 2qεt/m

Velocity of mass 2m after time t is -

v1 = qε/2m × t

v1 = qεt/2m

Kinetic energy of mass m is -

E1 = 1/2 m1.v1^2

E1 = 1/2 × m × (2qεt/m)^2

E1 = 2(qεt)²/m

Kinetic energy of mass 4m is -

E2 = 1/2 m2.v1^2

E2 = 1/2 × 2m × (qεt/2m)^2

E2 = (qεt)²/4m

Ratio of kinetic energies is -

E1/E2 = [2(qεt)²/m] / [(qεt)²/4m]

E1/E2 = 8

Therefore, ratio of kinetic energies is 8:1.

Thanks dear...