Something hot like a fire , an eye of a stove , and the sun
Answer:
A. 2.82 eV
B. 439nm
C. 59.5 angstroms
Explanation:
A. To calculate the energy of the photon emitted you use the following formula:
(1)
n1: final state = 5
n2: initial state = 2
Where the energy is electron volts. You replace the values of n1 and n2 in the equation (1):

B. The energy of the emitted photon is given by the following formula:
(2)
h: Planck's constant = 6.62*10^{-34} kgm^2/s
c: speed of light = 3*10^8 m/s
λ: wavelength of the photon
You first convert the energy from eV to J:

Next, you use the equation (2) and solve for λ:

C. The radius of the orbit is given by:
(3)
where ao is the Bohr's radius = 2.380 Angstroms
You use the equation (3) with n=5:

hence, the radius of the atom in its 5-th state is 59.5 anstrongs
Answer:
(a). The reactive power is 799.99 KVAR.
(c). The reactive power of a capacitor to be connected across the load to raise the power factor to 0.95 is 790.05 KVAR.
Explanation:
Given that,
Power factor = 0.6
Power = 600 kVA
(a). We need to calculate the reactive power
Using formula of reactive power
...(I)
We need to calculate the 
Using formula of 

Put the value into the formula


Put the value of Φ in equation (I)


(b). We draw the power triangle
(c). We need to calculate the reactive power of a capacitor to be connected across the load to raise the power factor to 0.95
Using formula of reactive power


We need to calculate the difference between Q and Q'

Put the value into the formula


Hence, (a). The reactive power is 799.99 KVAR.
(c). The reactive power of a capacitor to be connected across the load to raise the power factor to 0.95 is 790.05 KVAR.
Answer:
Acceleration will be equal to
Explanation:
We have given mass of the object m = 0.4 kg
Spring constant k = 8 N/m
Maximum displacement of the spring is given x = 0.1 m
From newton's law force is equal to
.....eqn 1
By hook's law spring force is equal to
.....eqn 2
From equation 1 and equation 2



So acceleration will be equal to 
Answer: 71 J
Explanation: The formula for gravitational potential energy is Epg= mgh.
So you plug in 2.2 as m, 3.3 as h and 9.81 as g. Once you do that you should get an answer of 71.2206. But because there are only two significant digits in the question, your answer must also have two significant digits.