A force of 5 N gives a mass m1, an acceleration of 10 m s–2 and a mass m2 , an acceleration of 20 m s-2 . What acceleration would it give if both the masses were tied together?

Solution:
m₁ = F/a₁ ; and
m₂ = F/a₂ . Here, a₁ = 10 m s^-2;
a₂ = 20 m s^-2 and F = 5 N.
Thus, m₁ = 5 N/10 m s^-2 = 0.50 kg; and
m₂ = 5 N/20 m s^-2 = 0.25 kg.
If the two masses were tied together,
the total mass, m would be
m = 0.50 kg + 0.25 kg = 0.75 kg.
The acceleration, a produced in the combined mass by the 5 N force would
be, a = F/m = 5 N / 0.75 kg = 6.67 m s^-2
.