Newton's Law of Gravitation can be used to show that if an object weighs w pounds on the surface of the earth, then its weight at a distance x from the center of the earth is W(x)=wR2x2 (for x≥R), where R=3960 miles is the radius of the earth. Estimate the altitude at which a 120- lb pilot would weigh 119.5 lb

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.

1) what is the power in horsepower of a 100 watt light bulb? what is the power in kilowatts of a 200 horsepower engine? 2) if a cars engine is providing 3000 n of force to keep the car moving at 5 m/s, what is the engine’s effective power? 3) how many gallons of water will be pumped from a well 30 feet deep by a 1/2 hp engine in 1 minute? (1 gallon weighs 8.34 pounds)