The net force in box 1 is determined as 5 N.
The acceleration of box 1 is determined as 5 m/s².
How to calculate the net force in box 1?
The net force in box 1 is calculated by applying Newton's second law of motion as shown below;
F(net) = thrust force - friction force
The given parameters include;
thrust force = 7 N
friction force = 2 N
F(net) = 7 N - 2 N
F(net) = 5 N
The acceleration of the box is calculated as follows;
a = F (net) / mass
a = 5 N / 1 kg
a = 5 m/s²