Question

Minimum force required to move a block of mass 10 kg on a horizontal surface whose co efficient of friction is just sufficient to prevent slipping on an inclined of angle 37 degrees with horizontal

Answer 1

Block will begin to slide before being lifted.

Explanation:

There is minimum a magnitude of forces required, both in horizontal and vertical direction, either to slide or lift up the block. The block will first slide or lift up depending on which force is more.

For the block to lift up,

F sin 37 + n - Mg >= =

N becomes zero on just lifting condition.

Flift >= 10g/ (3/5) = 500/3 N

For the block to slide,

F cos 27 >= UsN

F cos 37 . 0.5 [ 10g - F sin 37]

F slide > 50 / (cos 37 + 0.5 sin 37)

F slide > 500 / N

F lift > 500 / 3 N

We get that F slide  is less than F lift.

So the block will begin to slide before being lifted.