A racecar on a straight track, starting from rest*, steps on the accelerates towards the finish line at 10.0 m/s^2. If the finish line is
500.0m away, how yong does it take the car to cross the finish line?"
A 5.08
B 10.05
C 20.05
D 50.0s
E 100.0

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?