Answer:
E = 1.51 × 10²¹ J
Step-by-step explanation:
Given:
Rest mass of the spaceship, m = 120 metric tonn = 120 × 10³ kg
Speed, v = 0.481 c
Now,
the relativistic kinetic energy required is calculated as:

where, c is the speed of the light = 3 × 10⁸ m/s
on substituting the respective values, we get

or
E = 1.51 × 10²¹ J