Question

2 persons just manage to push a block from left to right direction along a horizontal level road with uniform velocity when the same block is pushed by 3 person in same direction a constant acceleration of 0.2 metre per second square is produced in the block if the 5persons push the block in same direction together then the magnitude of the acceleration of the Block will be

Answer 1

When 2 person pulls the box it will move to the right with constant speed

So applied force = friction force

$F_f = 2F$

When 3 person apply force on it

$3F - F_f = ma$

$3F - 2F = 0.2m$

Now when 5 person apply the same force then we have

$5F - F_f = ma$

$5F - 2F = ma$

$3F = ma$

from above equation F = 0.2m

$3*0.2m = ma$

$a = 0.6 m/s^2$

so acceleration will be 0.6 m/s^2

Answer 2

When 2 person pulls the box it will move to the right with constant speed

So applied force = friction force

F_f = 2FFf​=2F

When 3 person apply force on it

3F - F_f = ma3F−Ff​=ma

3F - 2F = 0.2m3F−2F=0.2m

Now when 5 person apply the same force then we have

5F - F_f = ma5F−Ff​=ma

5F - 2F = ma5F−2F=ma

3F = ma3F=ma

from above equation F = 0.2m

3*0.2m = ma3∗0.2m=ma

a = 0.6 m/s^2a=0.6m/s2

so acceleration will be 0.6 m/s^2