During the winter vacation, children use snow and water to build frictionless slides of different shapes in order to conduct various experiments. The sides view of one of them is shown in the figure. The linear segments of the slide is smoothly transfered to a circle with a of radius R . A puck starts sliding down from rest at initial height of 2R. the acceleration of the puck at the lowest point of its trajectory is

Options

A. g
B. 2g
C. 4g
D. 0

Answer

C

Explanation

`mgxx2R=1/2 mv^(2)`
`v^(2)=4gR`
`a_(N)=(v^(2))/R= 4g`