Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by
For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
C and d have the same amount of protons and electrons
Answer:
The new length is 50.00885m
Explanation:
linear thermal expansion coefficient Fe 11.8e-6 /K
The new length can be determined using the following equation:
∆L/L = α∆T, where α is linear thermal expansion coefficient
∆L = Lα∆T = 50(11.8e-6)(35-20) = 0.00885 m
New length = ( 50.000 + 0.00885)m =
New length = 50.00885 m
Conduction. Because they are connected as they tranfer energy
Answer:
friction reduces the efficiency of machines, thus we must reduce the friction force that is acting upon it.