Forces of 11.5 N north, 20.4 N east, and 15.7 N south are simultaneously applied to a 3.74 kg mass as it rests on an air table. What is the magnitude of its acceleration?

Answer 1

Total Force = mass*acceleration

Add the forces together by adding the horizontal and vertical components individual and then using the Pythagorean theorem to find the hypotenuse (a.k.a total force)

For the vertical components, let North be +, while South be -. For the horizontal component, let East be +.

vertical component (y):
11.5N -15.7N

horizontal component (x):
20.4 N

total force:
sqrt[(11.5N -15.7N)^2 + (20.4N)^2]

now plug it into newton's second law equation (see above)