A 2 g ball of glass is released from the edge of a hemispherical cup whose radius is 20 cm. What is the speed of the ball when it reaches the bottom of the cup? (Take g = 10 m s^(-2))

A 2 g ball of glass is released from the edge of a hemispherical cup w

1.	A 2 g ball of glass is released from the edge of a hemispherical cup whose radius is 20 cm. What is the speed of the ball when it reaches the bottom of the cup? (Take g = 10 m s^(-2))
Answer» `2 m s^(-1)` `4 m s^(-1)` `8 ms^(-1)` `10 m s^(-1)` Solution :According to the conservation of ENERGY , kinetic energy at A + potential energy at A = kinetic energy at B + potential energy at B `:. 0 + mgh = 1/2 mv^2 + 0` or `v^2= 2gh = 2 XX 10 xx 0.20 = 4` `[ :. h = "RADIUS" = 20 cm = 0.2 m]` or `v = 2 ms^(-1)`