Physics Work, Energy, Power and Collision NTA Abhiyas Question - Center of Mass and Momentum Conservation (Collision) MCQ (Single Correct)

A ball starts falling under the effect of gravitational force from a height of 45 m. When it reaches a height of 25 m it explodes into two pieces of mass ratio 1:2. There is no change in the vertical motion of the pieces after the explosion but they acquire horizontal velocity. If the heavier piece gains a horizontal velocity of 10 ms -1 , then the distance between the two pieces when both of them strike the ground is

A
30 m
B
10 m
C
20 m
D
15 m

Share this question

For Instagram sharing, use “Apps” on mobile or copy the link.

Text Solution

Verified by Experts
The correct answer is:
A

Let us assume the mass of the ball is 3m and the velocity of the lighter piece in horizontal direction after the explosion is v. We know that just after the collision, the horizontal velocity of the heavier piece is 10ms -1 . Using conservation of momentum in the horizontal direction we get

mv = 2m x 10

v = 20ms -1

Since there is no change in vertical motion, the time taken by the pieces to reach the ground can be

calculated in the following way.

Total time to fall through 45 m is

The time taken to fall through first 20 m is

Hence time taken by the pieces to fall from 25 m height to ground is

T 40 - T 20 = 3 - 2 = 1 s

The relative velocity of the pieces in the horizontal direction is

v rel = v - (-10) = 30ms -1

The horizontal distance between the two pieces at the time of striking the ground is

x = 30 x 1 = 30 m

Prepare Smarter with CGP Edu

Get practice questions, solutions, and test series in one place.

Write a Review

Share your experience with this question and solution.

Commentary

Send your comment, doubt, correction, or feedback to admin.

Student Reviews

What students say about this solution

No reviews yet. Be the first to write a review.

Similar Questions

Explore conceptually related problems

CG
CGP Question Assistant Question Bank + AI Help
Hi! Type your question or upload one screenshot. First I will search related questions from CGP Edu Question Bank. If none match, type YES and I will solve it with AI.
Upload only one screenshot at a time. Flow: Question Bank first → If not matched, type YES for AI solution.