Answer: <u>To establish a point from which to measure a future distance, or if movement has occurred.</u>
Explanation:
A reference point is a point with respect to which one comes to know whether any movement has occurred or not. A still point is required. When the object changes distance from that point, it means that object has moved. The distance can be calculated from one point to another.
Therefore, A reference point is used to establish a point from which future distance or if movement has occurred is detected.
As electrons move through the conductor, some collide with atoms, other electrons, or impurities in the metal.
Answer:
a)
, b) 
Explanation:
The magnitude of torque is a form of moment, that is, a product of force and lever arm (distance), and force is the product of mass and acceleration for rotating systems with constant mass. That is:



Where
is the angular acceleration, which is constant as torque is constant. Angular deceleration experimented by the unpowered flywheel is:


Now, angular velocities of the unpowered flywheel at 50 seconds and 100 seconds are, respectively:
a) t = 50 s.


b) t = 100 s.
Given that friction is of reactive nature. Frictional torque works on the unpowered flywheel until angular velocity is reduced to zero, whose instant is:


Since
, then the angular velocity is equal to zero. Therefore:

To solve this problem it is necessary to address the concepts related to Torque as a function of the force and distance where it is applied and the moment of inertia from which the torque, moment of inertia and angular acceleration are related.
By definition the torque is defined as

Where,

F = Force
r = Radius
For our values we have:



Consequently the calculation of the moment of inertia would then be given by the relationship


Replacing with our values


The moment of inertia of the boxer's forearm 