Adisc on a frictionless axle, starting from rest (0 rpm) can spin up to a rotation rate of 3820 rpm in a period of 2 seconds. (this is equivalent to angular acceleration of 200 rad/s.) moment of inertia of disc = 5 kg-m. a) how much net torque was applied to the disc during the 2-s period?b) how much net torque would be needed to change the angular acceleration to 400 rad/s"?c) if the angular acceleration is 400 rad/s, how long will it take to spin up from 0 to 3820 rpm?

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?