Which of the following is a poor conductor of heat?. A. silver. B. aluminum. C. gold. D. copper. E. air. How can you tell the di
2 answers:
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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:
2.00 m/s²
Explanation:
Given
The Mass of the metal safe, M = 108kg
Pushing force applied by the burglar, F = 534 N
Co-efficient of kinetic friction, = 0.3
Now,
The force against the kinetic friction is given as:
Where,
N = Normal reaction
g= acceleration due to the gravity
Substituting the values in the above equation, we get
or
Now, the net force on to the metal safe is
Substituting the values in the equation we get
or
also,
acceleration of the safe
Therefore, the acceleration of the metal safe will be
acceleration of the safe=
or
acceleration of the safe=
or
acceleration of the safe=
Hence, the acceleration of the metal safe will be 2.00 m/s²