Answer:
a.
b.
c. 
d. The angular acceleration when sitting in the middle is larger.
Explanation:
a. The magnitude of the torque is given by 
, being r the radius, F the force aplied and 
the angle between the vector force and the vector radius. Since 
and so 
.
b. Since the relation 
hols, being I the moment of inertia, the angular acceleration can be calculated by 
. Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is 
, being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by 
, being 
the mass of the person and 
the distance from the person to the center. Given all of this, we have
.
c. Similar equation to b, but changing 
, so
.
d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.
Efficiency = useful energy out / total energy in x 100
= 100/400 x 100
=0.25 x 100
= 25%
25%
Sonar<span> (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.</span>
Observe that the object below moves in the negative direction with a changing velocity. An object which moves in the negative direction has a negative velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a positive acceleration). The dot diagram shows that each consecutive dot is not the same distance apart (i.e., a changing velocity). The position-time graph shows that the slope is changing (meaning a changing velocity) and negative (meaning a negative velocity). The velocity-time graph shows a line with a positive (upward) slope (meaning that there is a positive acceleration); the line is located in the negative region of the graph (corresponding to a negative velocity). The acceleration-time graph shows a horizontal line in the positive region of the graph (meaning a positive acceleration).
I don't know how I can show you the figure
Tom used more Force but over a shorter distance. Tom and Claudia both did the same amount of work.
