Physics question about speed in three dimensions?

Question

A 3.90 kg penguin runs onto a huge horizontal sheet of frictionless ice. The sheet lies on the xy-plane. At t = 0 s it is at x = 0 m and y = 0 m with an initial speed of 0.71 m/s along the positive x-axis. It slides while being pushed by the wind with a force of 0.53 N directed along the positive y-axis. Calculate the penguin's speed at t = 7.43 s.

Answer 1

Its x velocity will stay the same, and it's y velocity will increase with an acceleration of F/m=a=.53/3.9=.136 m/s². So, at t=7.43 s it will have a y velocity component of v=at=.136*7.43=1.01 m/s. That, with its initial x velocity will give a speed of
s=√(vx²+vy²)=√(.71²+1.01²)=1.235 m/s.

HTH

Doug

Answer 2

a. 1.2343542181898930575016723040587 by Doug's method
b. Trick question. You said "question about speed in three dimensions" but only have information about two.
c. Due to global warming, the ice melts and the penguin falls into the water. Speed becomes zero.