Which sentence is a correct statement of Newton's second law? An object in motion stays in motion, and an object at rest stays at rest unless acted upon by a net force.

Every mass in the universe is attracted to every other mass in the universe.

Every action has an equal and opposite reaction.

When an object experiences a net force, it will accelerate at a rate determined by its mass.

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

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.)

A75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. the motor operates 4368 hours a year at a load factor of 0.75. taking the cost of electricity to be $0.12/kwh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. also, determine the simple payback period if the pu