True or false: friction, gravity, and walking forces

[cash.money]

Homework Statement

1. The force that propels you forward as you walk across the floor is the force that is exerted by the floor itself. T or F

2. If you were sitting half as far from your nearest classmate, the gravitational force of attraction between the two of you would be four times as strong. T or F

3. For any pair of surfaces, the coefficient of static friction between the surfaces is less than the corresponding coefficient of sliding friction. T or F

Homework Equations

The Attempt at a Solution

 

[musiliu]

1. Hint: This depends on friction or frictionless surface.
2. Hint: Gravity acts downward.
3. Hint: It is harder to get past static friction than kinetic or sliding friction.