Answer:
D.-1500Joules
Explanation:
The change in kinetic energy of the object s equivalent to the workdone by the body in the west direction (negative x direction)
Workdone = Force * Distance
Given
Force = 30N
Distance moved by the object = 30m
Required
Kinetic energy
Kinetic energy = 30 * 50
Kinetic energy = 1500Joules
Since the body moves in the negative direction, hence the kinetic energy will be -1500Joules