Answer:
the moment of inertia with the arms extended is Io and when the arms are lowered the moment
I₀/I > 1 ⇒ w > w₀
Explanation:
The angular momentum is conserved if the external torques in the system are zero, this is achieved because the friction with the ice is very small,
L₀ = L_f
I₀ w₀ = I w
w =
w₀
where we see that the angular velocity changes according to the relation of the angular moments, if we approximate the body as a cylinder with two point charges, weight of the arms
I₀ = I_cylinder + 2 m r²
where r is the distance from the center of mass of the arms to the axis of rotation, the moment of inertia of the cylinder does not change, therefore changing the distance of the arms changes the moment of inertia.
If we say that the moment of inertia with the arms extended is Io and when the arms are lowered the moment will be
I <I₀
I₀/I > 1 ⇒ w > w₀
therefore the angular velocity (rotations) must increase
in this way the skater can adjust his spin speed to the musician.
Answer:
A. kinetic energy
B. angular velocity
E. angular position
Explanation:
The quantities that cannot be constant if a constant net torque is exerted on an objecta are:
A. Kinetic energy. If a torque is applied, the linear or angular speed will be changing at a rate proportional to the torque, so the kinetic energy will change too.
B. Angular velocity. It will change at a rate equal to the torque.
C. Angular position. If the angular velocity changes, the angular position will change.
Answer: As Earth spins on its axis, we, as Earth-bound observers, spin past this background of distant stars. As Earth spins, the stars appear to move across our night sky from east to west, for the same reason that our Sun appears to “rise” in the east and “set” in the west.
Explanation:
The answer is food irradiation. This involves the brief exposure of food to gamma rays or X-rays to kill pathogens that may contribute to food spoilage. This increases the shelf-life of the food. Gamma rays and X-rays emanate from nuclear decay of radioactive materials such as uranium..