Question

A rocket of mass 6000 kg is set for vertical firing, if the exhaust speed be 1 km s-1, the gas must be ejected to give the rocket an upward acceleration of 20 ms-2 ​

Answer 1

Explanation:

Given, m=6000kg

v=900m/s

a=20m/s

2

dt

dm

=?

Here, upward thrust =F

th

=

dt

dm

v

Also, m(g+a)=F

th

=v

dt

dm

∴

dt

dm

=

v

m(g+a)

=

900

6000(10+20)

=

9

60×30

=20×10

∴

dt

dm

=200kg/s.