Two brothers, frank and dion, are on roller skates and standing still when they push off from one another. frank's mass is 103.4 kg. dion's mass is 51.6 kg. after they push off, frank has a velocity of -7 m/s. what will dion's velocity be?

The experiments with static charges were done by:

Ascientific blank must be testable and capable of being proven false?

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".