A car horn creates a 595 Hz tone at rest. Two cars pass on the
street, each going 20.0 m/s; the
first car honks. What frequency
does the other car hear after they
pass each other?
(Speed of sound = 343 m/s)
(Unit = Hz)

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".