# Newton's Laws problem

1. Aug 12, 2007

### Alyce777

1. The problem statement, all variables and given/known data
Peter and John are playing a game of tuf-of-war on a frictionless icy surface. Peter weighs 539N and John weighs 392N. DUring the course of the game, John accelerates toward Peter at a rate of 2.0m/s^2.
a) What is the magnitude of the force that Peter exerts on John?
b)What is the magnitude of the force that John exerts on Peter?
c) What is the magnitude of Peters acceleration toward John?

2. Relevant equations

F=ma

3. The attempt at a solution

so I'm really stuck with this one. Firstly, I'm not sure how to convert from weight to mass, I looked up a converter that said to multiply by 0.102 to get the weight in kg. ( did this, peter=55kg, john = 40kg). I'm not sure if that's right though. I also can't tell the difference between the questions, especially b and c. What are the variables in the first two questions? I think I should be solving for Newtons, but again, I'm just stuck. Any help would be appreciated

2. Aug 12, 2007

### rootX

-Go through the Newton's third law.
-mass(in kg) = W/g

3. Aug 12, 2007

### Alyce777

Yea I've got the weights right, with the 55 and 40kg, I figured that part out. What I can't get is what the three questions are asking. Part C i got as being 120N but don't know what to use in a) and b)

4. Aug 12, 2007

### rootX

ok, so acceleration of the john is given,
and thus using F=ma you can find the force that is being applied on him.
and that would be the answer to "a) What is the magnitude of the force that Peter exerts on John?"

and using newton's third law, you can find answer to the part b