<h2>
Answer: 10615 nm</h2>
Explanation:
This problem can be solved by the Wien's displacement law, which relates the wavelength 
where the intensity of the radiation is maximum (also called peak wavelength) with the temperature 
of the black body.
In other words:
<em>There is an inverse relationship between the wavelength at which the emission peak of a blackbody occurs and its temperature.</em>
Being this expresed as:
(1)
Where:
is in Kelvin (K)
is the <u>wavelength of the emission peak</u> in meters (m).
is the <u>Wien constant</u>, whose value is 
From this we can deduce that the higher the black body temperature, the shorter the maximum wavelength of emission will be.
Now, let's apply equation (1), finding :
(2)
Finally:
This is the peak wavelength for radiation from ice at 273 K, and corresponds to the<u> infrared.</u>
Answer:
909.1 m
Explanation:
Rate of temperature increase with 100 m elevation = 1°C
h = Maximum Height
Adiabatic lapse rate = -0.65°C/100 m
We have the relation
The maximum height is 909.1 m
Electrical energy is used to run the fan
Here as per given condition 750 J of electrical energy is used to run the fan which is converted into Kinetic energy as 400 J
So here we can see that 350 J of energy is lost against many other type of frictional and resistive loses.
So here we can say that out of 750 J of energy only 400 J is used to run the fan and rest amount of energy is lost against friction.
also we can say that efficiency of this fan will be
Answer:
It determines how long you do a certain workout.
Answer:
26b) 66.7%
27) 500 N
Explanation:
26.a) In a two pulley system, the load is attached to one of the pulleys. The other pulley is attached to a fixed surface, as well as one end of the rope. The other end of the rope goes around moving pulley, then around the fixed pulley.
26.b) Mechanical advantage is the ratio between the forces:
MA = load force / effort force
Efficiency is the ratio between the work:
e = work done on load / work done by effort
Work is force times distance.
e = (F load × d load) / (F effort × d effort)
Rearranging:
e = (F load / F effort) × (d load / d effort)
e = MA × (d load / d effort)
In a two pulley system, the load moves half the distance of the effort. So the efficiency is:
e = (4/3) × (1/2)
e = 2/3
e = 66.7%
27) In a three pulley system, the load moves a third of the distance of the effort.
e = (F load / F effort) × (d load / d effort)
0.40 = (600 N / F) × (1/3)
F = 500 N
