Question

A rocket has total mass 1000 kg with fuel of 900 kg it ejects fuel at the rate of 1kg/s with an exhaust velocity of 2km/s relative to rocket the maximum velocity attained by rocket is

Answer 1

Answer:celerated is continuously decreasing (fuel is being ejected from the rocket).

Solution

The momentum of the ejected fuel gas is

p=mgv.

The ejection velocity v=2.5×102m/s is constant, and therefore the force is

F=

dp

dt

=v

dmg

dt

=−v

dm

dt

.

Now,

dmg

dt

is the rate of change of the mass of the fuel; the problem states that this is 2.0×102kg/s. Substituting, we get

F =v

dmg

dt

=(2.5×102

m

s

)(2.0×102

kg

s

) =5×104N.

Explanation: