# Analyzing Force vs. Time graphs

1. Oct 30, 2007

### physics_wtf

1. I REALLY need help here! I've been doing pretty good in physics so far this year, but a new quiz devastated me. Here's the problem:
I was given a Force vs. Time graph and a lot of the questions pertained to the mass of the object. How do I find the mass only given a F vs T graph?

2. Relevant equations
Is there any other data I can obtain from a Force/Time graph? (like acceleration, velocity, or something to do w/ friction)?

2. Oct 30, 2007

### Kurdt

Staff Emeritus
A force time graph is all about impulse, and impulse is the change in momentum of an object.

3. Oct 30, 2007

### tyco05

Impulse is given by the area under an F-t graph.

As Kurdt said, impulse is the change in momentum of an object. ie. p2 - p1 or m(v2 - v1) [for constant mass].

4. Oct 31, 2007

### FrixioN911

If you're solely given the Force of an object over Time... I don't see how you could find the mass of the object unless you were somehow able to calculate the acceleration.

If the object was traveling around a circular path, and you were given the velocity or able to calculate the velocity and the radius of the circle, then you could substitute (v^2)/r as the acceleration...

But I believe, as in introductory physics, the equation F=ma has to come into play here.
(or F=(mv^2)/r)

NOW, you might have been told that this was a free-falling object, or a nuance similar. In which case, that gives you the acceleration (9.8 m/s^2)- so it may be tricky.

5. Oct 31, 2007

### tyco05

If it is analysing a collision, which F-t graphs are so often used for, and you know the initial and final velocities, then the mass can be found from the relationship in my last post.