Mass of the box which contains books (m) = 9.5 kg
Acceleration required (a) = 1 m/s^2
Let the force applied by the teacher and student be F.
The only force acting in the horizontal direction is F and it will produce an acceleration of 1 m/s^2
According to Newton's Seconds law:
F(net) = ma
F = ma
F = 9.5 × 1
F = 9.5 Newtons
Hence, the sideways force applied by teacher and the students is equal to 9.5 Newtons
