Answer:

Explanation:
Given that:
- area of concrete slab,

- thickness of the layer of air,

- temperature difference between the air and the concrete,

We have:
- thermal conductivity of air at S.T.P.,

<u>Now, according to Fourier's Law of conduction:</u>

putting the respective values:


Answer:
The wave length of the string = 10 cm or 0.1 m
Explanation:
Wave: A wave can be defined as a disturbance, which travels through a medium and transfer energy from one point to another, without causing any permanent displacement of the medium itself.
The velocity, frequency and wavelength of a wave is related as shown,
v = λf ........................ Equation 1
Where v = velocity of the wave, λ = wave length, f = frequency.
λ = v/f ..................... Equation 2.
Given: v = 10 cm/s,
T = 2t, where t = 0.5 s, (This is half of one cycle)
T = 2×0.5 = 1 s,
But T = 1/f = 1/1 = 1 Hz.
Substituting these values into equation 2
λ = 10(1)
λ = 10 cm. or 0.1 m
Thus the wave length of the waves = 10 cm or 0.1 m
Potential energy is given as

now as we know that force is related by potential energy by the formula

So it is gradient of energy with position in Y


Now at y = 0

at y = 1


at y = 2


so above is the forces at given positions
Answer:
part (a). 176580 J
part (b). 197381 J
Explanation:
Given,
- Density of the chain =

- Length of the chain = L = 60 m
- Acceleration due to gravity = g = 9.81

part (a)
Let dy be the small element of the chain at a distance of 'y' from the ground.
mass of the small element of the chain = 
Work done due to the small element,

Total work done to wind the entire chain = w

part (b)
- mass of the block connected to the chain = m = 35 kg
Total work done to wind the chain = work done due to the chain + work done due to the mass

Answer:
confounding cause they had exposure to many programmes