Question

A ball is rolling to and fro in a smooth circular cup as shown in figure below . It goes up to either side of the lowest point A to point 10 cm high above A. what is the speed of the vall at A?(g = 9.8m/s-2)
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Answer 1

Potential energy at point 10cm high than A will be:

$P_E=mgh\\P_E=m(9.8)(10^{-1})\\P_E=0.98m$

At point A, this energy is converted to kinetic energy.

$K_E=P_E\\\\\frac{mv^2}{2}=0.98m\\\\v^2=1.96\\v=1.4m/s$

Answer 2

Answer:

U = mgh

U = m(9.8)(1/10)

U = 0..98m

KE = U

1/2mv2 = mgh

1/2v2 = 0.98

v2 = 1.96

v = 1.4 m/s2