You are wearing skates and standing on a frictionless ice rink. Strapped to your back is jet pack that can produce a constant horizontal force of 75 lbf = 334 N. If you switch on the jet pack, what is your speed after 5 seconds?

23.2 m/s

Explanation:

A jetpack appliang a force on a body would result in an acceleration following Newton's equation:

f = m * a

Rearranging:

a = f / m

The problem doesn't state a mass, so I'll use mine, which is

m = 72 kg

Then:

a = 334 / 72 = 4.64 m/s^2

The equation for speed under constant acceleration is:

V (t) = V0 + a * t

Since I was standing before turning the jetpack on

V0 = 0

So:

V (5) = 0 + 4.64 * 5 = 23.2 m/s