A rocket with a lift -off mass 20 , 000 kg is blasted upwards with an initial acceleration of `5.0"ms"^(-2)` . Calculate the initial thrust (force) of the blast .

Explanation

Here , `m=20000kg=2xx10^(4)kg`
Initial acceleration , `a = 5 ms ^(-2)`,
Thrust , F = ?
Clearly , the thrust should be such that it overcomes the force of gravity besides giving it an upward acceleration of `5ms^(-2)` .
Thus the force should produce a net acceleration of 9.8+5.0 = `14.8ms^(-2)` .
As thrust = force = mass `xx` acceleration
`thereforeF=2xx10^(4)xx14.8=2.96xx10^(5)N`