An unhappy individual is trying to slide a 100 kg desk across a wood floor. He pushes with a force of 800 N but the desk does not move. One can conclude that the force of friction (relative to the applied force of 800 N) is:kg m/s2 is a valid unit for what measurement?

The experiments with static charges were done by:

What is the single most important equation in all of physics?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".