Learning Introductory Physics with Activities

An Olympic high diver in midair pulls her legs inward toward her chest. Doing so changes which of these quantities?

A typical small rescue helicopter has four blades. Each blade is \(4.0 \mathrm{~m}\) long and has a mass of \(50.0 \mathrm{~kg}\text{.}\) The blades can be approximated as thin rods that rotate about one end of an axis perpendicular to their length. The helicopter has a total loaded mass of \(1000 \mathrm{~kg}\text{.}\) Calculate the rotational kinetic energy in the blades when they rotate at \(300 \mathrm{~rpm}\text{.}\)

A typical small rescue helicopter has four blades. Each blade is \(4.00 \mathrm{~m}\) long and has a mass of \(50.0 \mathrm{~kg}\text{.}\) The blades can be approximated as thin rods that rotate about one end of an axis perpendicular to their length. The helicopter has a total loaded mass of \(1000 \mathrm{~kg}\text{.}\) What is the ratio of translational kinetic energy of the helicopter over the rotational kinetic energy of its blades when it flies at \(20.0 \mathrm{~m/s}\text{?}\)

A typical small rescue helicopter has four blades. Each blade is \(4.00 \mathrm{~m}\) long and has a mass of \(50.0 \mathrm{~kg}\text{.}\) The blades can be approximated as thin rods that rotate about one end of an axis perpendicular to their length. The helicopter has a total loaded mass of \(1000 \mathrm{~kg}\text{.}\) To what height could the helicopter be raised if all of the rotational kinetic energy could be used to lift it?