KVPY2011PhysicsMotion in Two Dimensions
The surface of a planet is found to be uniformly charged. When a particle of mass m and no charge is thrown at an angle from the surface of the planet, it has a parabolic trajectory as in projectile motion with horizontal range L . A particle of mass m and charge q , with the same initial conditions has a range L / 2 . The range of particle of mass m and charge 2 q with the same initial conditions is-
Options
- AL
- BL / 2
- CL / 3
- DL/4
Correct answer
C. L / 3
Step-by-step solution
For uncharged particle L = u ² 2 g ...(i) Range for particle of mass m and charge q . L 2 = u² 2 g+ q E m ...(ii) From (i) and (ii) array l u² 2 2 g = u² 2 g+ q E m m g=q E array Range of particle of mass m & charge 2 q . R = u ² 2 g + 2 q E m = u ² 2 g (1+ 2 qE mg ) = L 3