Question

A small block is released from rest inside a cylinderical [fixed] pipe of radius R = 3m as shown in the figure. Speed of the block when it reaches B from A is (coefficient of friction between block & cylinder is $\mu =0.7$ and $g=10m/s^2$). Write the answer until two digits after the decimal point.

Answer 1

By work energy theorem $\text{/}mgR-\mu \text{/}mgR=\frac{1}{2}\text{/}m{v}^2$
$gR(1-\mu )=\frac{v^2}{2}$
$v=\sqrt{2gR(1-\mu )}=\sqrt{2\times 10\times 3(1-0.7)}$
$v=3\sqrt{2}=4.242m/s$