Helicopter

Definition

A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors. It can take off, land vertically, and hover due to its rotating blades.

5 Must Know Facts For Your Next Test

1. Helicopters exhibit fixed-axis rotation where the main rotor acts as the axis of rotation.
2. The moment of inertia for a helicopter's rotor is crucial for determining its rotational kinetic energy.
3. Rotational kinetic energy of a helicopter rotor can be calculated using $KE_{rot} = \frac{1}{2} I \omega^2$, where $I$ is the moment of inertia and $\omega$ is angular velocity.
4. The distribution of mass in the helicopter's rotor blades significantly affects its moment of inertia.
5. Gyroscopic effects from the spinning rotor impact the stability and control mechanisms of helicopters.

Review Questions

• What formulas are used to calculate the moment of inertia and rotational kinetic energy for a helicopter's rotors?
• How does mass distribution in helicopter blades influence its moment of inertia?
• Explain how gyroscopic effects impact a helicopter’s stability during flight.

Related terms

Moment of Inertia:

A measure of an object's resistance to changes to its rotation. For a system with discrete masses, it's calculated as $I = \sum m_i r_i^2$.

Rotational Kinetic Energy:

$KE_{rot}$ is the energy due to rotational motion, given by $\frac{1}{2} I \omega^2$, where $I$ is moment of inertia and $\omega$ is angular velocity.

Angular Velocity:

$\omega$ represents how fast an object rotates or revolves relative to another point, often measured in radians per second.