Q129 / 160 · TS EAMCET 2019 (03 May Shift 2) · Physics

A solid spherical ball rolls on a horizontal surface at 10 m s-1 and continues to roll up on an inclined surface as shown in the figure. If the mass of the ball is 11 kg and frictional losses are negligible, the value of h, where the ball stops and starts rolling down the inclination is (Assume g=10 m s-2)

Figure

  • A
    8 m
  • B
    6 m
  • Correct answer
    C
    7 m
  • D
    10 m

Solution

Given,

Initial velocity of solid spherical ball is v=10 m s-1

Mass of ball rolling on the surface is m=11 kg

Applying work energy theorem,

W=∆KE

Wg=KEf-KEi    ...1

Now, initial kinetic energy of spherical ball is Ki=12mv21+k2R2

And final kinetic energy is given by

Kf=0

Work done due to gravity is 

Wg=-mgh

Substitute the values in equation (1) we get

⇒  -mgh=0-12×11×1021+25

Where, k2R2=25

⇒  h=35050=7 m

Hence, the correct answer is option: 'C'.

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