A particle is traveling in a straight line at a constant speed of 25.4 m/s. Suddenly, a constant force of 12.8 N acts on it, bringing it to a stop in a distance of 58.6 m.

Question

How long does it take to stop and what is the mass of the particle?

*Don't I need one of those two given to answer this question?*

Answer 1

Vf^2 = Vo^2 + 2ad = 0,
645.16 + 2 * a * 58.6 = 0,
645.16 + 117.2a = 0,
117a = -645.16,
a = -645.16 / 117.2 = -5.5m/s^2.

F = ma,
m = F / a = 12.8 / 5.5 = 2.32kg.