Answer:
60 N.C
Explanation:
The box will move in the direction of the push and pull with a force of 60 N. C.
The net force acting on the object perpendicular to the table is
∑ F[perp] = F[normal] - mg = 0
where mg is the weight of the object. Then
F[normal] = mg = (15 kg) (9.8 m/s²) = 147 N
The maximum magnitude of static friction is then
0.40 F[normal] = 58.8 N
which means the applied 40 N force is not enough to make the object start to move. So the object has zero acceleration and does not move.
