Calculate the momentum of the cart at time t=5

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

What is the rate of 12 liters of water moving through a water hose in 4.0 minutes?

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.)