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JEE Main 20238 AprilEvening Shift
Exam
JEE Main
Year
2023
Date
8 April
Shift
Evening Shift
Subject
Physics
Chapter
Work, Power and Energy

JEE Main 2023 · 8 April · Evening Shift · Physics · Work, Power and Energy

A hollow spherical ball of uniform density rolls up a curved...

A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity 3ms−13m{s}^{- 1} (as shown in figure). Maximum height with respect to the initial position covered by it will be _____ cmcm
(take, g=10ms−2g = 10m{s}^{- 2})

A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity 3m s ^ - 1 (as shown in

Correct answer

0

Step-by-step solution

A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity 3m s ^ - 1 (as shown in

The total kinetic energy of the ball at the bottom of the curve can be calculated as follows:

{K=12Mv2+12⋅23MR2ω2=12Mv2+13M(Rω)2=12Mv2+13Mv2[∵v=\omegaR]=56Mv2...(1)\begin{cases}K & = & \dfrac{1}{2}M{v}^{2} + \dfrac{1}{2} \cdot \dfrac{2}{3}M{R}^{2}{\omega}^{2} \\ & = & \dfrac{1}{2}M{v}^{2} + \dfrac{1}{3}M{\left(R\omega\right)}^{2} \\ & = & \dfrac{1}{2}M{v}^{2} + \dfrac{1}{3}M{v}^{2}\left[∵ v = \omegaR\right] \\ & = & \dfrac{5}{6}M{v}^{2} . . . \left(1\right)\end{cases}

The formula to calculate the potential energy acquired by the ball when it attains the maximum height is given by

U=Mgh...(2)U = Mgh . . . \left(2\right)

Equate equation (1) and (2) and simplify to obtain the required height.

{Mgh=56Mv2⇒h=5v26g...(3)\begin{cases}Mgh & = & \dfrac{5}{6}M{v}^{2} \\ & ⇒ & h = \dfrac{5{v}^{2}}{6g} . . . \left(3\right)\end{cases}

Substitute the values of the known parameters into equation (3) to calculate the required height attained by the ball.
{h=5×(3ms−1)26×10ms−2=0.75m×100cm1m=75cm\begin{cases}h & = & \dfrac{5 \times {\left(3m{s}^{- 1}\right)}^{2}}{6 \times 10m{s}^{- 2}} \\ & = & 0 . 75m \times \dfrac{100cm}{1m} \\ & = & 75cm\end{cases}

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