A typical helicopter has four blades that rotate at 313 rpm and have a total kinetic energy of 4.20 * 10^5 J. What is the magnitude of the total angular momentum of the blades about the axis of rotation?
The total kinetic energy of the helicopter blades is given by

The angular velocity of the blades is

Putting it in the equation above


The angular momentum is given by

So, the answer is 2.56 x 104 kg.m2/s.
A typical helicopter has four blades that rotate at 313 rpm and have a total kinetic...
A helicopter has two blades (see figure), each of which has a mass of 250 kg and can be approximated as a thin rod of length 6.7 m. The blades are rotating at an angular speed of 53 rad/s. (a) What is the total moment of inertia of the two blades about the axis of rotation? (a) Determine the rotational kinetic energy of the spinning blades.
A helicopter has two blades (see figure), each of which has a
mass of 240 kg and can be approximated as a thin rod of length 6.7
m. The blades are rotating at an angular speed of 43 rad/s.
(a) What is the total moment of inertia of the two
blades about the axis of rotation? (a) Determine
the rotational kinetic energy of the spinning blades.
Two equal spheres, one has a hole and the other is completely solid rotate with the same angular velocity on its axis of rotation. If both have the same mass and radius. Which of them has the highest kinetic energy of rotation or have the same kinetic energy of rotation? Select one and explain.
The tail rotor section of a Black Hawk helicopter consists of four blades, each has a mass of 2 [kg), and a gear box that weights 38 [kg]. The center of gravity of each blade is 0.4 [m] from the rotational axis. The tail section is connected to the main body of the helicopter by an elastic structure. The natural frequency of the tail section is observed as 135 [rad/s]. During flight, the rotor operates at 850 [r/min). 1- Calculate...
Given
• Hollow hoop has a mass M and radius R. It is free to rotate about
an axis perpendicular to the page and the edge of the hoop.
Released frm rest, passes through horizontal in final state, and
rotates right
Question
A. Direction of final angular velocity and acceleration
vector?
B. Rotational inertia of hoop about axis before it is released
Do the following increase, decrease,, or remain the
same (Between final and initial)
C. Magnitude of gravitational PE...
What is the angular kinetic energy of the Earth due to its orbit around the sun? In Homework 10, you found the two main angular velocities of the Earth: one due to the Earth's motion around the sun, and one due to its rotation about its own axis. Now let's figure out the energy and momentum associated with that motion. IVO ALV O a ? For the purposes of this problem, treat the Earth as a solid, uniform sphere with...
2. A rigid sphere with mass 20 Kg and radius 0.6 m is free to rotate around a fixed axis passing through its center (I = 2/5 mR2). The sphere is initially at rest. A force of 4 N is applied at the edge (or equator) of the sphere, tangent to the sphere and perpendicular to the sphere radius, generating a constant torque for 3 s. (i) Calculate the magnitude of the angular acceleration of the sphere. (ii) Calculate the...
1a. A cockroach of mass m lies on the rim of a uniform
disk of mass 9.00 m that can rotate freely about its
center like a merry-go-round. Initially the cockroach and disk
rotate together with an angular velocity of 0.456 rad/s. Then the
cockroach walks halfway to the center of the disk.
(a) What then is the angular velocity of the
cockroach-disk system?
(b) What is the ratio
K/K0 of the new kinetic energy of the
system to its...
(10) Problem i Aanhas four blades attached to a central shaft. The blades are distributed mass of 0.17 kl. The fan spins up from rest to an angular speed of y 15 cm long o have en forma 339 Part (a) Treat each fan blade as a uniform rod of length le rotating about its end. Enter an expression for the total change in the angular momentum AL of the fan during the spin up. Assume the angular momentum of...
Assume that the earth is a uniform sphere and that its path around the sun is circular.(a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. For comparison, the total energy used in the United States in one yearis about 9.33 109 J.J(b) Calculate the kinetic energy that the earth has because of its motion around the sun.J