Chapter 8, Problem 34RE

Hydraulic pressure of 705.0 pounds per square inch is exerted on a 3.150-inch diameter piston. Find the total force exerted on the piston. Round the answer to the nearest pound.

A strong wind holds a kite 30 ft above the earth in a position 40 ft across the ground. How much string does the girl let out to the kite?

When the Radius Increases a. A rope is wrapped tightly around a wheel with radius of 2 feet. If the radius of the wheel is increased by 1 foot to a radius 3 feet, by how much must the rope be lengthened to fit around the wheel? b. Consider a rope wrapped around the Earths equator. We noted in Exercise 17 that the radius of the Earth is about 4000 miles. That is 21,120,000 feet. Suppose now that rope is to be suspended exactly 1 foot above the equator. By how much must the rope be lengthened to accomplish this? The Size of the Earth The radius of the Earth is approximately 4000 miles. a. How far is it around the equator? Hint: You are looking for the circumference of a circle b. What is the volume of the Earth? Hint: The volume of a sphere of radius r is given by 43r3. b. What is the surface area of the Earth? Hint: The surface area of a sphere of radius r is given by 4r2.