Question

What is the magnitude of the resultant force, in newtons, acting on an object that has two forces acting in the same direction having magnitudes of 15 newtons and 25 newtons and a third force acting perpendicular to the first two having a magnitude of 30 newtons?

Answer 1

Imagining that the forces form a right triangle (since the 3rd force is acting perpendicularly) then the resultant force can simply be calculated using the hypotenuse formula:

c^2 = a^2 + b^2

Where a and b is equivalent to:

a = 15 N + 25 N = 40 N

b = 30 N

Therefore the resultant force is then calculated:

c^2 = (40 N)^2 + (30 N)^2

c^2 = 1,600 + 900

c^2 = 2,500

c = 50 N