6. Intro to Forces (Dynamics)

According to Newton's First and Second Laws, the distance required for a vehicle to stop safely depends on which of the following factors?

A simple elevator ride can teach us about Newton's First and Second Laws. When an elevator accelerates upward, what happens to the normal force exerted by the floor on a person standing inside compared to when the elevator is at rest?

According to Newton's Second Law, if an object of mass $m$ is accelerating at a rate $a$, what is the magnitude $F$ of the net force acting on the object?

For an ideal pulley (negligible mass and friction), which of the following can the pulley change?

A person is running on a track. Which of the following forces propels the runner forward?

Why does bending your legs when running enable you to swing your legs to and fro more rapidly?

According to Newton's First Law, what will a baseball that is standing still on a table do if no net force $F\_\mathrm{net}$ acts on it?

According to Newton's Second Law, which force is responsible for causing the acceleration of an object ($F=ma$)?

Which of the following is the best example of an unbalanced force acting on an object?

Which of the following equations correctly expresses Newton's Second Law, relating force, mass, and acceleration?

A horizontal shaft is supported by a smooth thrust bearing at point A and a smooth journal bearing at point B. If a force $F$ is applied perpendicular to the shaft at its midpoint, which statement best describes the reaction forces at the supports according to Newton's First and Second Laws?

When switch S in the figure is closed at time $t=0$, which of the following best describes the motion of a block of mass $m$ attached to a horizontal frictionless surface and pulled by a constant force $F$?

Which of the following explanations is contrary to Newton's first law of motion?