Ann is driving down a street at 60 km/h. Suddenly a child runs into the street.
If it takes Ann 0.72 s to react and apply the
brakes, how far will she have moved before
she begins to slow down?
Answer in units of 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?