# Homework Help: Newton's First and Second Laws

1. Sep 29, 2010

### EndOfMemories

1. The problem statement, all variables and given/known data

A particle is traveling in a straight line at a constant speed of 25.0 m/s. Suddenly, a constant force of 15.0 N acts on it, bringing it to a stop in a distance of 62.5 m.
(a) What is the direction of the force?
(b) Determine the time it takes for the particle to come to a stop.
(c) What is its mass?

2. Relevant equations

F=ma

3. The attempt at a solution

Okay, I figured out that the direction of the constant force must be opposite of the particle, otherwise the particle will never stop. I am unable to come up with way to solve the problem so if you guys can shed light on what I can do, that will be awesome

2. Sep 29, 2010

### PhanthomJay

You have one of the equations; you need to use the kinematic equations of motion for constant acceleration to find the acceleration and time.

3. Sep 29, 2010

### EndOfMemories

Okay, thanks for the direction! I got it now.