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QJEEM21Phd5e7: JEE Main 2021 Physics - Class 11 JEEM21Phd5e7 Solution: A ball of mass 10 kg moving with a velocity 10 3 m/s along the…

A ball of mass 10 kg moving with a velocity 103 m/s along the x-axis, hits another ball of mass 20 kg which is at rest. After the collision, first ball comes to rest while the second ball disintegrates into two equal pieces. One piece starts moving along y-axis with a speed of 10 m/s. The second piece starts moving at an angle of 30∘ with respect to the x-axis. The velocity of the ball moving at 30∘ with x-axis is x m/s. The configuration of pieces after collision is shown in the figure below. The value of x to the nearest integer is ____________.

JEE Main 2021 (Online) 18th March Morning Shift Physics - Center of Mass and Collision Question 54 English

Step-by-Step Verified Solution

Velocity of 10 kg ball = v10=103i^

initial total momentum of system = 10×103i^

Final total momentum of system

=10×10j^+10×x(cos⁡30∘i^−sin⁡30∘j^)

Now by conservation of momentum

10×103i^=10×10j^+10×x(32i^−12j^)

⇒ x = 20

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