A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m . It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a

Question

A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m . It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is

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Answer:

B

Solution:

Using conservation of energy, $m (10 \times 100) = m (\frac{1}{2} v^{2} + 10 \times 20)$ or $\frac{1}{2} v^{2} = 800$ or $v = 1600 = 40 m / s$

TestHub · Accepted Answer

Using conservation of energy, m ( 10 × 100 ) = m ( 2 1 ​ v 2 + 10 × 20 ) or 2 1 ​ v 2 = 800 or v = 1600 ​ = 40 m / s

Physics - W.E.P. Question with Solution | TestHub

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