Question

If the force on a rocket, that releases the exhaust
gases with a velocity of 300 m/s is 210 N, then
the rate of combustion of the fuel is
(1) 0.07 kg/s
(2) 1.4 kg/s
(3) 0.7 kg/s
(4) 10.7 kg/s​

Answer 1

Answer:

0.7 kg/s

Explanation:

Force acting on the rocket,

F = 210 N

relative velocity =300 m/s

$f = \frac{d}{dt}(mv) \\ f=> v \frac{dm}{dt}$

$210 = 300 \times \frac{dm}{dt}$

$=> \frac{dm}{dt} = \frac{210}{300}$

$=> 0.7 \: kg /s$

hence rate of combustion of fuel is 0.7 kg/s

Hope it helps

Answer 2

Answer:

option ( 3 ) 0.7 kg/s

See the above mentioned attachment .