The figure shows two forces acting on an object,with magnitudes F₁ = 78 N and F₂ = 26 N.What third force will cause the object to be in equilibrium? A)52 N pointing down B)52 N pointing up C)82 N pointing down D)82 N pointing up

Question

Quizplus · Accepted Answer

To achieve equilibrium, the net force acting on the object must be zero. Therefore, the third force must be equal in magnitude and opposite in direction to the vector sum of the first two forces. Using the Pythagorean theorem and trigonometry, we can find that the vector sum of the two forces has a magnitude of 85 N and points 19.1 degrees below the horizontal. Thus, a third force with a magnitude of 52 N and pointing downward (in the opposite direction of the vector sum) will balance out the system and create equilibrium. Therefore, the answer is choice A.

The Figure Shows Two Forces Acting on an Object,with Magnitudes