# Homework Help: Person's acceleration and object's acceleration

1. Oct 16, 2007

### pebbles

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

A man with mass 80 kg exerts force of 150 N on 500 kg object. What is his accleration and what is the acceleration of the object? (assume no external forces)

2. Relevant equations
a=f/m

3. The attempt at a solution

not sure how to calculate the acceleration of object, but would i calculate the acceleration of the man like this--> a=150 N/80 kg...?

Last edited: Oct 16, 2007
2. Oct 16, 2007

### thylow

Draw a Free body diagram. Mass of man, force horizontal on the 500kg object. With every action there is an equal and opposite reaction. When the forces have been solved and equal to each other. Solve the acceleration using a = 150 N/500kg for the acceleration of the object. The acceleration of the man is right what you put down. Just make sure you have it in the right direction

I'll answer other questions on my website listed in my profile.

3. Oct 16, 2007

### pebbles

accel. for object, would i put a negative sign in front of the answer since it's a problem dealing with newton's third law..?

4. Oct 16, 2007

### thylow

Well yea.. but draw your coordinate system in your Free body diagram. so that your teacher knows.