Question Detail

PHY 101 PHY 101 Past Questions Objective Question
Take CBT

Question

Newton's second law for a system of particles states that the net external force on the system equals:
Options
A The sum of all internal forces.
B The total mass multiplied by the acceleration of the center of mass.
Correct Answer
C The rate of change of the system's total potential energy.
D Zero, if the system is in equilibrium.
Correct Answer

Option B is the correct answer.

Detailed Explanation

The lecture gives ΣF_ext = M a_CM. Internal forces cancel out in pairs and do not affect the motion of the center of mass. The center of mass accelerates as if it were a single particle of mass M under the influence of the net external force.

Hint

This is why the motion of a firework's center of mass is unaffected by its explosion.

Question Info

Course: PHY 101
Topic: PHY 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 498 of 1250
Previous Course Details Next