Question

A rocket with a lift-off mass 20,000 kg is blasted upwards with an initial acceleration of 5.0 m s^–2. Calculate the initial thrust (force) of the blast.

Answer 1

Mass of the rocket, m = 20,000 kg
Initial acceleration, a = 5 m/s²
Acceleration due to gravity, g = 10 m/s²
Using Newton’s second law of motion, the net force (thrust) acting on the rocket is given by the relation:
F – mg = ma
F = m (g + a)
= 20000 × (10 + 5) = 20000 × 15 = 3 x10⁵ N