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.

According to the Newton’s second law of motion, the net force on the rocket can be given as,

F – mg = ma


F = m (g + a)


Where,


‘m’ is the mass of the rocket,


a is the acceleration of the rocket


g is the acceleration due to gravity= 10 m/s2


Given,


Mass of the rocket, m = 20,000 kg


Initial acceleration of the rocket, a = 5 m/s2


Thus, the initial thrust can be calculated as,


F= 20000 kg×(10+5) m/s2


F = 20000 kg × 15 m/s2 = 3 × 105 N


The initial thrust of the blasted rocket is 3 × 105 N.


13