How can I calculate the net force of an object?
What is the meaning of net force?
Net force means the resultant.
It’s very easy to find resultant , if you have knowledge in trigonometry.
Here you can see where the resultant force of each object acts
In below image consider the object in left hand .(Here you have to deal with angles)
In first image all forces are act in vertical direction, but in situation ##A## It’s not, so we have to get the resultant .
Resolving forces to the horizontal direction
##150N cos ## ##30^.##- ##60N##
Resolving forces to the vertical downward direction
##196N## – ##121N##.
Why we resolved it horizontal direction & vertical direction?
When finding resultant we should resolve forces into perpendicular direction.Why we should resolve forces into perpendicular direction?
Consider the image below,
##F##= Resultant force.
In situation ##A## , what is ##F_x## and ##F_y## ?
##F_x## = ##60N##
##F_y## = -##121N##,
So to find the resultant force we need both direction and magnitude ,because force is a vector quantity
So here
Magnitude of resultant here is ##(18241)^(1/2)##= ##135N##
Direction of resultant= ##arctan##(2) = ##63.43.## degrees to the horizontal.
Then in situation ##A## magnitude of net force is 135N and it is inclined ##63.43.## degrees to the horizontal.
Likewise you can calculate resultant.