A rocket of mass 40 kg has 160 kg fuel. The exhaust velocity of the fuel is 2km s−1. The rate of consumption of fuel is 4kg s−1. Calculate the ultimate vertical speed gained by the rocket.
1) 2.82km s−1
2) 4.82km s−1
3) 3.61km s−1
4) 5.62km s−1
1) 2.82km s−1
2) 4.82km s−1
3) 3.61km s−1
4) 5.62km s−1