Question

68. The coefficient of static & kinetic
friction are 0.6 & 0.3 The minimum
horizontal force required to start the
motion is applied and if it is continued, the
distance travelled by the body in 4 sec is
(g=10ms-2)
1) 6 m 2) 24 m 3) 2.4 m 4) 5m​

Answer 1

Explanation:

Static friction is a self-adjusting force.

The limiting value of friction up to which the body stays at rest till it starts moving is given by, Fs=μmg

where μ is the coefficient of static friction.

Below that limit, the frictional force is equal to the force applied.

Here Fs=0.8×4×10=32N ;   g=10m/s2

Whereas force applied is 19N less than the limiting value of friction.

Hence Frictional force is 19N.