Correct option: (B) 960 J
Explanation:
Because the acceleration of wedge is zero, the normal reaction exerted by wedge on block is N = mg cos 37°.
The acceleration of the block is g sin 37° along the incline and initial velocity of the block is v = 10 m/s horizontally towards right as shown in figure.
The component of velocity of the block normal to the incline is v sin 37°. Hence the displacement of the block normal to the incline in t = 2 second is
S = v sin 37° × 2 = 10 × 3/5 × 2 = 12 m.
∴ The work done by normal reaction
W = mg cos 37° S = 100 x 4/5 × 12 = 960 J