Adding force vectors and then calculating acceleration.

1. Jul 18, 2013

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

Two forces act simultaneously on a body of mass 15 gram. The magnitudes of the
forces are 1 Newton and 3 Newton, and the angle between them is 60° as shown. Find the
magnitude of the acceleration of the body. Express your answer in m/s2 and to the nearest
integer.

2. Relevant equations

F = ma

3. The attempt at a solution

The sum of the two force vectors is √{1+9+(6*1/2)} =√13 .
Thus a =√13/(15/1000 kg) = ~240 .

2. Jul 18, 2013

barryj

I think you are correct.

3. Jul 18, 2013

haruspex

So do I. What answer is given?

4. Jul 19, 2013

The answer given is 67 .

5. Jul 19, 2013

haruspex

You'd get that acceleration from a force of 1N on 15g.

6. Jul 19, 2013