Find the kinetic energy of a block twice as massive (30kg) moving at the same speed (20m/s). (show the equation, show your work and answer with units.)

Asher cycles 12 miles in 16 hours. what is his speed?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)