Question

A rocket has a mass of 100 kg. 90% of this is fuel. It ejects fuel vapors at the rate of 1 kg/sec with a
velocity of 500 m/sec relative to the rocket. It is supposed that the rocket is outside the gravitational field. The initial upthrust on the rocket when it just starts moving upwards is:
​

Answer 1

Dear Student,

◆ Answer -

Initial upthrust = 500 N

◆ Explanation -

Let dm/dt be rate of ejection of gas and v be initial velocity.

# Given -

dm/dt = 1 kg/s

v = 500 m/s

# Solution -

Initial upthrust that beed to be provided is -

F = v.(dm/dt)

F = 500 × 1

F = 500 N

Therefore, 500 N of initial upthrust is provided.

Thanks dear...