A student connects an object with mass m to a rope with a length r and then rotates the rope around her head parallel to the ground. the object takes 0.5 seconds to complete one rotation. mass= 50 kg. length of the rope = 1.2 m
what is the objects speed of rotation?

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.

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".

Select all the correct answers. which two statements are true? a moving magnetic field creates an electric field. a constant magnetic field creates an electric field. a constant electric field creates a magnetic field. a moving electric field creates a magnetic field. resetnext