Class 9 Exam  >  Class 9 Questions  >   A girl of mass 20 kg having velocity 2 m/sec... Start Learning for Free
A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts moving
  • a)
    2 m/s
  • b)
    54 m/s
  • c)
    0.95 m/s
  • d)
    1.81 m/s
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart...
To solve this problem, we can use the principle of conservation of momentum. This principle states that the total momentum before an event is equal to the total momentum after the event, as long as no external forces are acting on the system.

Let's break down the problem into two parts: before the girl jumps onto the cart and after she jumps onto the cart.

Before the girl jumps:
- Girl's mass (m1) = 20 kg
- Girl's velocity (v1) = 2 m/s
- Cart's mass (m2) = 2 kg (stationary, so its velocity is 0)

After the girl jumps:
- Girl's mass (m1) = 20 kg
- Girl's velocity (v1') = ?
- Cart's mass (m2) = 2 kg
- Cart's velocity (v2') = ?

Using the principle of conservation of momentum, we can write the equation:
(m1 * v1) + (m2 * 0) = (m1 * v1') + (m2 * v2')

Simplifying the equation, we get:
(m1 * v1) = (m1 * v1') + (m2 * v2')

Plugging in the values, we have:
(20 kg * 2 m/s) = (20 kg * v1') + (2 kg * v2')

Simplifying further, we have:
40 kg m/s = 20 kg * v1' + 2 kg * v2'

Since the cart starts moving, its velocity (v2') is not zero. Therefore, we can rewrite the equation as:
40 kg m/s = 20 kg * v1' + 2 kg * v2'

To find the velocity of the girl when the cart starts moving (v1'), we need to know the value of v2'. Unfortunately, the problem does not provide this information.

Therefore, we cannot determine the exact velocity of the girl when the cart starts moving. The correct answer should be option 'Cannot be determined' or 'Insufficient information provided'. The given options do not include this choice, so none of them is correct.
Free Test
Community Answer
A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart...
If the two bodies stick to each other after
collision, they will move with a common velocity v given by
V =maua + mbub/ma + mb
Here, ma = 20 kg, ua = 2 m/s, mb = 2 kg, ub = 0
∴ v = 20 × 2 +2 × 0/20+2 = 40/22 = 1.81 m/s
Explore Courses for Class 9 exam

Top Courses for Class 9

A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer?
Question Description
A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? for Class 9 2025 is part of Class 9 preparation. The Question and answers have been prepared according to the Class 9 exam syllabus. Information about A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Class 9 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer?.
Solutions for A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 9. Download more important topics, notes, lectures and mock test series for Class 9 Exam by signing up for free.
Here you can find the meaning of A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A girl of mass 20 kg having velocity 2 m/sec jumps on stationary cart of mass 2 kg. Find the velocity of the girl when the cart starts movinga)2 m/sb)54 m/sc)0.95 m/sd)1.81 m/sCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Class 9 tests.
Explore Courses for Class 9 exam

Top Courses for Class 9

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev