Apiece of concrete pipe being stored at a construction site is shaken loose in an earthquake and rolls down a hill. The pipe is a cylindrical shell 2.0 m is diameter, 3.2m long and 5 cm thick. Concrete has a density of roughly 2300 kg/m3. When the pipe reaches the street after descending a vertical distance of 45m, how fast is it going?
A cylindrical section of tree trunk 50 cm in diameter and 75 cm long is seen rolling down a road below a saw hill at a speed of 12 m/s. (wood has a density of about 750 kg/m3) Assuming that the road has an incline 5% (meaning that if you travel 100 m along the slope of the road, you go up 5 m), at least how far up the road is the sawmill? Describe any assumptions or approximations that you make.
A basketball with a mass of 0.15 kg and a radius of 0.15 m is thrown to you rotating at 5 times per second. What is the magnitude of the frictional force that you have to exert on it with your hands to stop it rotating within 0.1s when you catch it? (Hint: the moment of inertia of a spherical shell is 2/3 MR2, where M and R are the shells mass and radius, respectively.)