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

Paragraph: A small block of mass $1\mathrm{kg}$ is released from rest at the top of a rough track. The track is a circular arc of radius $40\mathrm{m}$. The block slides along the track without toppling and a frictional force acts on it in the direction opposite to the instantaneous velocity. The work done in overcoming the friction up to the point $Q$, as shown in the figure below, is $150\mathrm{J}$. (Take the acceleration due to gravity, $g=10\mathrm{m}{\mathrm{s}}^{-2}$ ).

Question: The magnitude of the normal reaction that acts on the block at the point $Q$ is