The earth exerts a gravitational force of F(r)=2.99×1016r2 (in Newtons) on an object with a mass of 75 kg, where r is the distance (in meters) from the center of the earth. Find the rate of change of force with respect to distance at the surface of the earth, assuming the radius of the earth is 6.77×106 m.

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?

Aboat radioed a distress call to a coast guard station. at the time of the call, a vector a from the station to the boat had a magnitude of 45.0 km and was directed 15.0° east of north. a vector from the station to the point where the boat was later found is = 30.0 km, 15.0° north of east. what are the components of the vector from the point where the distress call was made to point where the boat was found? in other words, what are the components of vector c = b - a?

Avoltaic cell converts chemical energy to