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

Given: The mass of the rocket is 20,000 kg, the acceleration of the rocket is 5.0 m/ s 2 and the acceleration due to gravity is 10 m/ s 2 .

According to Newton’s second law of the motion, the net thrust force on the rocket is,

F−mg=ma F=m( g+a )

By substituting the given values in the above expression, we get

F=( 20,000 kg )( 10 m/ s 2 +5.0 m/ s 2 ) =3× 10 5  N

Thus, the thrust force on the rocket is 3× 10 5  N.