wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Scientists of ISRO want to achieve a velocity of rocket 100 m/s after time t=5 sec. Velocity of ejected burnt fuel is 20 m/s w.r.t the rocket. What should be the rate of consumption of fuel (approximately) so that the rocket will achieve the desired velocity?
Initial mass of rocket is 2000 kg. [Take g=10 m/s2]

A
300 kg/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
400 kg/s
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
100 kg/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
200 kg/s
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 400 kg/s
Given,
Initial mass of rocket m0=2000 kg.
Velocity of rocket after 5 sec v=100 m/s
Initial velocity u=0 m/s
Velocity of ejected burnt fuel vr=20 m/s
As we know, v=ugt+vrln(mom)
Here m=m0μt
=2000μ×5 ...(1)
Then,
100=010×5+20×ln(200020005μ)
7.5=ln(200020005μ)
1808.04=200020005μ
μ=399.78 kg/s400 kg/s

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
How Do Rockets Fly in Space?
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon