Laws of Motion - Result Question 30

30. A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block ( g is acceleration due to gravity) will be

[2004]

(a) mg/cosθ

(b) mgcosθ

(c) mgsinθ

(d) mg

Show Answer

Answer:

Correct Answer: 30. (a)

Solution:

  1. (a) According to the condition,

N=masinθ+mgcosθ

Also, mgsinθ=macosθ

From (1) & (2), a=gtanθ

N=mgsin2θcosθ+mgcosθ.

=mgcosθ(sin2θ+cos2θ)=mgcosθ or, N=mgcosθ

The condition for the body to be at rest relative to the inclined plane, a=gsinθbconθ=0 Horizontal acceleration, b=gtanθ.



NCERT Chapter Video Solution

Dual Pane