Question

A rocket is ejecting 1.2 kg of fuel per second at a velocity of 80km/s. The accelerating force on thr rocket will be?

Answer 1

Answer:

Mass ejection rate = 1 kg/s

Velocity of ejected mass = 60km/s = 60000 m/s

Accelerating force = 1×60000 kg.m/s^2 = 60000 N = 60 kN

The accelerating force on rocket is 60kN

Answer 2

Given :

mass of gas ejecting per sec = 1.2 Kg

Velocity of exhaust = 80 Km/sec

To Find :

The Accelerating Force on the rocket

Solution :

If the mass of gas ejected in time dt is dm, then the force is given as -

Force (F) = velocity of exhaust × $\frac{dm}{dt}$

              = 80×1000 × 1.2                (1km = 1000 m)

              = 80000 × 1.2

              = 96000 N

              = 9.6 × 10⁴ N

Therefore, the accelerating force on the rocket is 96000 N or 9.6 × 10⁴ N.