A hockey puck sliding on a frozen lake comes
to rest after traveling 207 m.
If its initial velocity is 4 m/s, what is its
acceleration (assumed constant)?
Answer in units of m/s
2
.
change in velocity / change in time = (0-4) / time = -4 / time
207 = average speed * time
average speed = (4+0)/2 = 2 m/s
so time = 207/2 =103.5 s
so
a = - 4/103.5 m/s^2
(not much friction :)