a student attaches a 0.5 kg object to a 0.7 m string and rotates the object around her head and parallel to the ground. how much tension force is required to make the object rotate with a speed of 12 m/s?

Explain earth's motion, using the terms "precession" and "rotation" in your answer.

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".

Photons with the highest energy have the longest period