Question

Which one of the following statements is not true about Newton’s second law of motion $\vec{F}=m\vec{a}$ ?

• A. The second law of motion is consistent with the first law
• B. The second law of motion is a vector law
• C. The second law of motion is applicable to a single point particle
• D. The second law of motion is not a local law

Answer 1

Answer: (D)

The second law of motion is a local law which means that force $\vec{F}$ at a point in space (location of the particle) at a certain instant of time is related to $\vec{a}$ at that point at that instant. Acceleration here and now is determined by the force here and now, not by any history of the motion of the particle.