The emf produced in a generator is Vemf = 25 sin 377t. What is the frequency of rotation of the circular coil?

50 Hz
60 Hz
25 Hz
15 HZ

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?