19. A spacecraft which is moving with a speed u relative to

Last updated: 7/10/2022

19. A spacecraft which is moving with a speed u relative to the earth in the x-direction, enters the gravitational field of a much more massive planet which is moving with a speed 3u in the negative x-direction. The spacecraft exits following the trajectory as shown below. The speed of the spacecraft with respect to the earth a long a time after it has escaped the planet's gravity is given by (a) u (b) 4u (c) 2u (d) 7u