A penguin has a mass of 13 kg. The penguin slides over the ice for a distance of 50.7 m in 1.7 s before coming to a complete stop. The penguin uniformly accelerates during the entire time period. What is the net force exerted on the penguin?

Answer 1

a = (final velocity-initial velocity) / time

a = (0 - Vi)/1.7

so a = -Vi/1.7

d = Vi t + (1/2) a t^2

50.7=Vi(1.7) -(1/2)(Vi/1.7)(1.7)^2

50.7 = (1/2)(1.7)Vi

Vi = 59.6 m/s
then
a = - Vi/1.7 = -35.1 m/s^2

so F = m a = 13(-35.1)
= - 456 N

Answer 2

Damon,

Thanks for answering my question. What I don't understand is why gravity is not an issue in this problem? Could you please explain?