Question

Q. Newton's second law is summarized in the equation F=ma. Which of the following is true regarding this equation?

A. To use this equation, you need to add all the forces together, accounting the different directions, before knowing what to put for F.

B. It's impossible to get any information from this equation until you know, ahead of time, exact values for F, m, and a.

C. To use this equation, you need to add all the forces together numerically, ignoring direction, before knowing what to put in for F.

D. To figure this out, you need to evaluate F=ma for each separate force acting on an object, and then average the results.

Answer 1

Answer: A. To use this equation, you need to add all the forces together, accounting the different directions, before knowing what to put for F.

Explanation: In Newton's second law the quantity F and a are vector quantity. So to write the equation we have to add all the forces acting on the body accouting the different directions along which the forces are acting ( i.e. We have to do the vector addition). The resultant direction of the forces is the direction of acceleration a (along which the particle is moving) .

so the correct answer is option A.

Thank You.