Question

Heather is sitting on her car at a spotlight. At the instant light turns green, she starts accelerating at 2.2 m/s/s. At the same moment a truck rumbles past her car going a constant speed of 12.2 m/s. Heather is infuriated at being passed by a truck and she keeps accelerating until she gets ahead of the truck.
A) How much time will it take her to catch up with the truck?
B) How far down the street will she will catch up with the truck?
C) How fast will she be moving at this point?

Answer 1

solve for t when the distances are equal:

0 + 1.1t^2 = 12.2t

Now recall that since she started from a dead stop,

s = 1/2 at^2
v = at