# How to find net force?

## Homework Statement

Find the magnitude of net force on the following object a 725 gram block that is accelerating at 8.10 m/s2 at an angle of 18.0 degree relative to horizontal.

F=m*a

## The Attempt at a Solution

I first converted the 725 grams to kilograms but then after that I am unsure of what to do. Having information about the angle is throwing me off because I don't know what equation to use.

PhanthomJay
Homework Helper
Gold Member
Read up again on Newton's 2nd law, the part about where it talks about the direction of the net force.

Well I did read that if you know the direction of acceleration, you know the direction of the net force. But I am still confused as to how this helps. Would you please explain more? Thank you!

What you have to do is find your force for your x-component and your force for your y-component and then find the magnitude of these. because its asking for magnitude.
so..
F_x = ma_x
and
F_y = ma_y

so for these equations obviously your mass will be the same value, but you must find your x and y component of accleration, which is an easy trig problem (draw a triangle)

you should be able to then easily solve for you F_x and F_y
once you find these you should know how to find the magnitude, its the square root of (F_x)^2 + (F_y)^2

PhanthomJay