# A rocket of mass 20 kg has 180 kg of fuel.The exhaust velocity of fuel is 1.6km/sec.Calculate the ultimate velocity of the rocket gained,when the rate of consumption of fuel is 2kg/sec.

148 Points
12 years ago

Velocity of rocket is given as

v=u ln(M/M-rt)

wher M is the total mass of rocket + fuel at t=0 sec = 20 +180 =200 kg

and r rate of fuel consumption =2kg/sec

u is the velocity of gas ejection w.r.t rocket = 1.6 km/sec

ultimate velocity is achieved when all the fuel will burn

ie. M-rt =20 kg

so v= 1.6 ln(180/20)

=3.515 km/sec

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Pavithra
15 Points
4 years ago
A rocket having initial mass of 240kg ejects fuel at the rate of 6kg/s with a velocity of 2km/s vertically downward relative to itself. Calculate its velocity 25seconds after start taking initial velocity to be zero and neglecting gravity

KUMARI
13 Points
3 years ago
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