Verified Solution • 2025–26 Session moderate

QJEEM22Ph1f41: JEE Main 2022 Physics - Class 11 JEEM22Ph1f41 Solution: A man of 60 kg is running on the road and suddenly jumps into a …

A man of 60 kg is running on the road and suddenly jumps into a stationary trolly car of mass 120 kg. Then, the trolly car starts moving with velocity 2 ms −- 1. The velocity of the running man was ___________ ms −- 1, when he jumps into the car.

Step-by-Step Verified Solution

Total momentum of (man + trolley) system is always conserved

Initially man was moving with velocity v1 and trolley was at rest, finally both were moving with velocity 2 ms −- 1 after man jumps on the trolley.

So,

⇒m1v1+0=(m1+m2)v2\Rightarrow \quad m_{1} v_{1}+0=\left(m_{1}+m_{2}\right) v_{2}

 Here, m1= mass of man =60 kg\text { Here, } m_{1}=\text { mass of man }=60 \mathrm{~kg}

m2= mass of trolley =120 kgm_{2}=\text { mass of trolley }=120 \mathrm{~kg}

v1= speed of  man v_{1}=\text { speed of } \text { man }

v2= speed of man and trolley =2 m/sv_{2}=\text { speed of man and trolley }=2 \mathrm{~m} / \mathrm{s}

⇒60×v1=(60+120)×2\Rightarrow 60 \times v_{1}=(60+120) \times 2

⇒v1=(60+120)×260=6 m/s\Rightarrow v_{1}=\frac{(60+120) \times 2}{60}=6 \mathrm{~m} / \mathrm{s}

Related Learning Resources & Exam Preparation

JEE Main PYQ Question Bank
Browse year-wise authentic previous years' questions with solutions
Authentic CBT Mock Tests
Simulate official exam environment with live timer and percentile scoring