Question

A rocket of mass 6000 kg is set for vertical firing. If the exhaust speed be 1 km/s, how much gas must be ejected to give the rocket an upward acceleration of 20 m s-2 ? (Take g = 10 m s-2)​

Answer 1

Explanation:

Answers

Answer:60kg

Explanation:

You have everythig to be put in the formula

F=V.dm/dt

F=m.g (here)

I.e.6000*10=60000

60000=1000*dm/dt

Therefore dm/dt = 60 kg/sec

We are now just asked how much weight to be ejected per sec .

Which is 60kg

Answer 2

Explanation:

Given A rocket of mass 6000 kg is set for vertical firing. If the exhaust speed be 1 km/s, how much gas must be ejected to give the rocket an upward acceleration of 20 m s-2 ?

• To push an object in the upward direction by upward force is the thrust.
• Therefore thrust = v.dm / dt
• Given gas ejected  m = 6000 kg
• The exhaust speed V = 1 km / s = 1000 m/s
• So acceleration of the rocket a = 20 m/s^2
• Also acceleration due to gravity g = 10 m / s^2
• We need to find dm / dt.
• So upward thrust = v . dm / dt
• Now v.dm/dt = m (g + a)
•       1000 . dm/dt = 6000 (10 + 20)
•       1000. dm/dt = 6000 x 30
•       Or dm/dt = 180000 / 1000
•      Or dm/dt = 180 kg / s

So amount of gas need to be ejected will be 180 kg / s  

Reference link will be

https://brainly.in/question/2215278