Answer:
Explanation:
fundamental frequency, f = 250 Hz
Let T be the tension in the string and length of the string is l ans m be the mass of the string initially.
the formula for the frequency is given by
.... (1)
Now the length is doubled ans the tension is four times but the mass remains same.
let the frequency is f'
.... (2)
Divide equation (2) by equation (1)
f' = √2 x f
f' = 1.414 x 250
f' = 353.5 Hz
The formula for force exerted on/by a spring is
F = k*e where k is the spring constant and x is the distance stretched from
unstrained position. This should allow you to find what you need.
Using F = k x e,
where k is the spring constant,
and e is the extension,
The F is her weight = 45 X 0.80
= 36 N
<span>Wind is nature's way of balancing the temperature between hot and cold. Wind always flows from heat to cool. When night falls, the air cools. And since it gets cooler at night it reverses.</span>
Answer: The major challenges are as
1) understanding of the plasma: Plasma is a soup like mixture of subatomic particles of different atoms nuclei and electrons that are shattered apart by the temperature at which plasma is formed. further research is needed to understand the behavior of plasma so that it can be put to a proper use.
2) Confinement of plasma: Once we get the plasma we need to hold it so that we can obtain heat from it to drive a steam turbine but the sheer temperature of plasma is in millions of Celsius thus currently making it impossible to confine conventionally. Scientists use a loop of electric and magnetic fields to keep it in circulatory like manner so that it can be studied.
3) finally to obtain electricity from the plasma it should be stable to produce electricity. But currently to obtain pressure, temperature so that we have a sustained supply is highly difficult in technical and economical aspects.
Inertial confinement: In order to get the nuclei of atoms close enough for fusion this type of method used compression of the nuclei into highly small volumes.This is accomplished by use of lasers which are directed towards the fuel pellets that implode and travel towards other nuclei making fusion possible. It's main advantage is that it requires lesser time to initiate fusion but the disadvantage being that a large power is used to fire the lasers and the lasers should all hit the small target.
Magnetic Confinement: In this method we use a magnetic and electric fields in a properly designed space to keep the plasma in motion. In motion the nuclei of the atoms come close enough to initiate fusion.It's advantage being less power is required to start the process as compared to inertial confinement and the disadvantage being that plasma confinement is currently not properly understood.
Explanation:
Speed is the rate of change of distance with time. It is a scalar quantity with magnitude both no direction.
Speed = 
The unit is m/s or km/hr or mile/hr
Distance covered is simply the length of the path traveled.
The unit is m or km or miles
Time taken is the duration of an event.
The unit is seconds or minutes or hour.
