How much force must be applied to accelaerate a 40 kg chair at 2.8m/s2?

Recall that force is mass times the acceleration:

F = m*a
where
m = mass (kg)
a = acceleration (m/s^2)

Substituting,
F = 4 * 2.8
F = ?

Solve for F. Units in Newtons.
Hope this helps~ `u`