Question

Given

g-10 m/s

Problem

Without using a calculator

A) draw and label free body diagrams for both masses after the rod is removed

B) if the coefficient of static friction us= 0.5, find the minimum pushing force required to keep the 1-kg mass from sliding down the face of the cart

Answer 1

A)

1Kq FeD vo nara

B) To prevent the mass from sliding down, force must be balanced in the vertical direction.

where fr is the frictional force on the mass and mg is the gravitational force.

now

$fr = \mu N$ , N is the normal reaction force.

$\therefore \mu N = mg$

$\therefore N = mg/\mu$

Now we write the force equation of the cart

as we need to find the minimum force required to prevent the sliding of the mass, the acceleration of the cart should be 0.

$\therefore F = N$

$\therefore F =mg/\mu$

Put the values given m = 1kg. g = 10 m/s²$\mu$ = 0.5

$\therefore F =1*10/.5$

$\therefore F = 20 N$