Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 9 Answered

A boy of mass 45 kg running 6 m/s jumps onto a 30 kg trolley moving in the same direction at 1.5 m/s. Their common velocity will be: A. 4.0 m/s B. 4.2 m/s C. 6.5 m/s D. 8.3 m/  
Asked by nishitatrambadia | 21 Oct, 2021, 09:38: AM
answered-by-expert Expert Answer

Using conservation of momentum

MV+mv = (M+m)v'

Where :
M- Mass of the boy= 45 kg
m- mass of the trolley = 30 kg
V- velcoity of the boy = 6 m/s
v- velocity of the trolley= 1.5m/s
v' - common velocity = x

(45 + 30) x = (45 x 6 + 30 x 1.5)

v' = x= 4.2 m/s

Hence, the common velocity of the 4.2 m/s.

Correct option is B

Answered by Shiwani Sawant | 21 Oct, 2021, 11:56: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test Subjective Questions Webinar Subjective Questions Pre Board Assessment
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
A boy of mass 45 kg running 6 m/s jumps onto a 30 kg trolley moving in the same direction at 1.5 m/s. Their common velocity will be: A. 4.0 m/s B. 4.2 m/s C. 6.5 m/s D. 8.3 m/  
Asked by nishitatrambadia | 21 Oct, 2021, 09:38: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is linear momentum ?
Asked by frusbJusyktsnis | 17 Sep, 2021, 12:03: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
a bullet of mass 20 grams is horizontally fired with a volicity of 150 mls from pistal of mass 2 kg what is the recoil volicity of pistal
Asked by gaminggaming64738 | 28 Jun, 2021, 10:30: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Two hockey players of opposite teams, while trying to hit a hockey ball on the ground collide and immediately become entangled. One has a mass of 60 kg and was moving with a velocity 5.0 m s–1 while the other has a mass of 55 kg and was moving faster with a velocity 6.0 m s–1 towards the first player. In which direction and with what velocity will they move after they become entangled? Assume that the frictional force acting between the feet of the two players and ground is negligible.
Asked by sasikumarsarala2020 | 25 Jun, 2021, 04:37: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
vehicle stops on applying brakes does this phenomena violate the principle of conservation of momentum momentum momentum
question image
Asked by neeteshvarshney6 | 20 Jul, 2020, 04:20: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
please answer fast
question image
Asked by tapandash1974 | 16 Jul, 2020, 05:39: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
question number 33
question image
Asked by neha14072006 | 21 Jun, 2020, 08:15: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A bullet of mass 3 kg is fired with a velocity of 150 metre per second find its momentum  
Asked by pnegi9416 | 29 Apr, 2020, 10:00: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A ball moving at a constant speed 10m/s, hits normally on a wall (mass of ball is 50g) and rebounds with same speed. The change in momentum is
Asked by mohitdhoni706 | 03 Apr, 2020, 01:20: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
The mass of a cannon is 500 kg.  From this cannon a bullet of 10 kg mass was thrown at a speed of 20 m / s.  How long does a cannon retreat if the resistance of the land is one tenth the weight of the cannon?
Asked by asishsengupta51 | 20 Feb, 2020, 11:24: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt

Be a Top Scorer in the Exam with Test Series and Test Generator!

Enrol Now
×