# physics

posted by .

Some special vehicles have spinning disks (flywheels) to store energy while they roll downhill. They use that stored energy to lift themselves uphill later on. Their flywheels have relatively small rotational masses but spin at enormous angular speeds. How would a flywheel’s kinetic energy change if its rotational mass were 7 times larger but its angular speed were 7 times smaller?

KE2/KE1 =

• physics -

Ke = (1/2) I w^2

KEmodified = (1/2)(7I)(w^2/49) = original Ke/7

• physics -

77

## Similar Questions

1. ### physics.

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible …
2. ### Physics

Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released quickly to accomplish a task that demands high power. An industrial flywheel has a 1.5 m diameter and a mass …
3. ### Physics

Two disks of identical mass but different radii (r and 2r) are spinning on frictionless bearings at the same angular speed ω0, but in opposite directions. The two disks are brought slowly together. The resulting frictional force …
4. ### physics

Flywheels are large massive wheels (disks) used to store energy. They can be spun up slowly, and then the wheel’s energy can be released quickly to accomplish a task that demands high power. A large flywheel has a 2.4 m diameter …
5. ### physics

There are two spinning disks A and B arranged so that they initially are separated but can be pushed into contact. Disk A is made of a lighter material, so it has a moment of inertia that is one third that of disk B. Disk A starts …
6. ### Physics

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible …
7. ### school

Two disks are spinning freely about axes that run through their respective centres (see figure below). The larger disk (R1 = 1.42 m) has a moment of inertia of 1180 kg · m2 and an angular speed of 4.0 rad/s. The smaller disk (R2 = …
8. ### physics

The flywheel of a motor is connected to the flywheel of an electric generator by a drive belt. The flywheels are of equal size each of radius . While the flywheels are rotating the tension in the upper and lower portions of the drive …
9. ### Physics

Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released quickly to accomplish a task that demands high power. An industrial flywheel has a 1.7 m diameter and a mass …
10. ### physics

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible …

More Similar Questions