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:
the number of photons of yellow light does the lamp generate in 1.0 s is 7 x 
Explanation:
given information:
power, P = 25 W
wavelength. λ - 580 nm = 5.80 x
m
time, t = 1 s
to calculate the number of photon(N), we use the following equation
N = λPt/hc
where
λ = wavelength (m)
P = power (W)
t = time interval (s)
h = Planck's constant (6.23 x
Js)
c = light's velocity (3 x
)
So,
N = λPt/hc
= (5.80 x
)(25)(1)/(6.23 x
)(3 x
)
= 7 x 
First, let's put 22 km/h in m/s:

Now the radial force required to keep an object of mass m, moving in circular motion around a radius R, is given by

The force of friction is given by the normal force (here, just the weight, mg) times the static coefficient of friction:

Notice we don't use the kinetic coefficient even though the bike is moving. This is because when the tires meet the road they are momentarily stationary with the road surface. Otherwise the bike is skidding.
Now set these equal, since friction is the only thing providing the ability to accelerate (turn) without skidding off the road in a line tangent to the curve:
Answer:
82.7 kg
Explanation:
the mass of the boxer remains unchanged, this is because mass is a measure of the quantity of matter in an object irrespective of its location and the gravitational force acting at its location. this means mass is independent of the gravitational acceleration hence it remains the same 82.7 kg. its unit is in kilograms (Kg).