Which is the wavelength of a wave that travels at a speed of 3.0 * 10^8 m/s and has a frequency of 1.5 x 10^16 Hz?

How is the gravitational force related to the distance between two objects?

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

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".