Answer:
doesn't move, no work is done; if a force is applied and the object moves a distance d in a direction other than the direction of the force, less work is done than if the object moves a distance d in the direction of the applied.
Answer:

Explanation:
means initial angular velocity, which is 0 rev/min
means final angular velocity, which is 
t means time t= 3.20 s
one revolution is equivalent to 2πrad so the final angular velocity is:
= (2π/60) *2.513*10^{4} rad/s
= 2628.5 rad/s
so the angular acceleration, α will be:
α = 2628.5 rad/s / 3.20 s

so the rotational motion about a fixed axis is:
+ 2αΔTita where ΔTita is the angle in radians
so now find the ΔTita the subject of the formula
ΔTita = 


<h2>
Answer: By the double slit experiment applied to electrons</h2>
The French physicist Louis De Broglie proposed the existence of matter waves, that is to say that <u>all matter has a wave associated with it.</u>
On the other hand, Heisenberg enunciated the uncertainty principle, which postulates that the fact that <u>each particle has a wave associated with i</u>t, imposes restrictions on the ability to determine its position and speed at the same time.
These postulations were tested with the double slit experiment (formerly applied to photons) applied to electrons, and the result was: electrons (as well as the other particles different from the photons) are able to behave as waves.
B, good luck, hope this helps :)