Three blocks `A` , `B` and `C` of masses `4kg` , `2kg` and `1kg` respectively are in contact on a frictionless surface, as shown. If a force of `14N is applied on the `4kg` block, then the contact force between `A` and `B` is.

Options

A. 6 6N
B. 8 N
C. 18 N
D. 2 N

Answer

a

Explanation

Here, `F = 14N`
`m_(A) = 4kg, m_(B) = 2kg, m_(C) = 1kg`
Total mass `m =m_(A) + m_(B) + m_(C)`
`= 4+ 2 + 1 = 7 kg`
Acceleration of the system
`a =(F)/(m) = (14)/(7) = 2m//s^(2)`
The contact force between `4kg` and `1kg` block with the same acceleration Let `F_(1)` be the contactv force
`:. F_(1) = (m_(B) + m_(C)) a = (2+1) = 6N`
.