A uniform bridge span of weight 1200 kN and of length 17.0 m rests on a support of width 1.0 m at
either end. A stationary lorry of weight 60 kN is the
only object on the bridge. Its centre of mass is 3.0m
from the centre of the bridge.
15.0 m

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

Which of the following is not an appropriate unit for acceleration? (kg/12 mihr? m/min/sec cm/30c?

What happens when the number of protons in an atom changes