Posted by ashley on .
A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 12 m/s, skates by with the puck. After 2.0 s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 4.0 m/s2, determine each of the following.
(a) How long does it take him to catch his opponent?(b) How far has he traveled in that time?

physics 
Henry,
a. d1 = Vo*t + at^2,
d2 = 12(t+2),
d1 = d2,
0 + 0.5*4t^2 = 12(t+2),
2t^2 = 12t + 24,
2t^2  12t  24 = 0,
Divide both sides by 2:
t^2  6t  12 = 0.
Use Quadratic Formula to find t:
t = 7.58s.
b. d = 0 + 0.5*4*(7.58)^2 = 114.9s.