A cart is moving along a positive direction with a velocity of 4 m/s. a person on the cart throws a stone with a velocity of 6 m/s with respect to himself. in the frame of reference of the cart the stone iss thrown in the y=z plane making an angle of 30 degrees with the verticalz axis. then with respect to an observer on the ground

a) the initial velocity of the stone is 10 m/s

b) the initial velocity of the stone is 2 * root of 13 m/s.

c)the velocity at the highest point of motion is zero.

d)the velocity at the highest point of its motion is 5 m/s

Assuming that the cart is moving in the positive x direction (Pls write the question carefully),

Only option (b) is correct. Option (c) is not correct because even at the highest point the velocity of the stone is 4m/s in the positive x direction. Option (a) is not correct as the vectors cannot be simply added as they r perpendicular to each other. Option(d) is incorrect as velocity at highest point is 4 m/s not 5m/s 

Srry fr a slight mistake in the prev reply.

Actually the option(d) is also correct. At its highest point it has a velocity of 5m/s. This is becoz it has a velcoity of 3m/s in the y direction and 4m/s n the x direction