Question

If the thrust force on a rocket which is ejecting gases with a relative velocity of 300 m/s is 210 N. Then the rate of combustion of the fuel will be:

• A. 10.7 kg/sec
• B. 0.07 kg/sec
• C. 1.4 kg/sec
• D. 0.7 kg/sec

Answer 1

The correct option is D 0.7 kg/sec

Relative velocity v$=$300m/s ; thrust foce F$=$210N mass of combustion of fuel $m=?$
thrust force$=$mv/t
210$=m\times 300$
m/t$=0.7kg/sec$
Hence,option D is correct.