Explanation:
It is given that,
Length of the helicopter, l = 3.1 m
The helicopter rotates, the length of helicopter will become the radius of circular path, r = 3.1 m
Angular speed of the helicopter, 
(a) The centripetal acceleration in terms of angular velocity is given by :



(b) Let v is the linear speed of the tip. The relation between the linear and angular speed is given by :


v = 90.89 m/s

Hence, this is the required solution.
When water soaks into the ground fast it means the soil is very moist
Answer:
D. Because mass and energy are both conserved, the total amounts of mass and energy are the same before and after impact.
Explanation:
As we know that, the energy in motion is Kinetic Energy mathematically given as:

<u>Now, according to the law of conservation of energy:</u>

where:
mass of racquet and ball respectively and
are their respective initial velocities.
are the respective final velocities.
<u>Also the law of conservation of momentum is applicable in this case:</u>

In this case the velocity of the lighter mass will get increases in the final condition.
Answer:
The difference between P-N junction diode and extrinsic semiconductor is the allowable direction of flow of current
The extrinsic semiconductor can allow current to flow in both directions while the P-N junction diode permits only a unidirectional flow of current
Explanation:
A semiconductor is a substance that has an intermediate conductivity between that of conductors and non conductors
Examples of semiconductors include germanium and cadmium selenide
A semiconductor to which impurities has been added (an activity known as doping) is an extrinsic semiconductor
Based on the functioning of a semiconductor, doping result in the formation of one of two types of semiconductors including;
1) N-type semiconductor that has an extra electron and the charge carriers are electrons
2) P-type semiconductor that has one less (-e⁻) electron and holes are the charge carriers
An extrinsic semiconductor can conduct allow the flow of electricity in both ways
A P-N junction diode consists of both the P and N-type extrinsic semiconductors arranged such that current can flow in only one direction.
Therefore, the difference is that the extrinsic semiconductor can allow current flow in both directions while the P-N junction diode permits only a unidirectional flow of current.