Block A as shown in figure weight `1.40 N` and block B weight `4.20 N` The coefficient of kinetic friction between all surface is `0.30` Find the magnitude of the horizontal force necessary to drag block B to the left at constant speed if A and B are connected by a light , fiexible cort passing around a fixed , frictionless pulled.

Options

A. `2 N`
B. `3 N`
C. `4 N`
D. `5 N`

Answer

d

Explanation

`F = f_(l_1) + f_(l_2) + T, T = f_(l_1)`
`F = 2f_(l_1)+ f_(l_2) = 3 N`