Answer:
25m/sec
Explanation:
Speed of car in first 15 minutes = 40 km/h
Distance covered = speed × Time taken
60 minutes = 1 hour
15 minutes =
60
15
hour
Distance covered = 240×
60
15
=10km
Speed of car in next 15 minutes = 60 km/h
Distance covered = 60×
60
15
=15km
∴ Total distance covered = (10+15)km = 25 km
Answer:
The wavelength of next line in the series will be 397.05 nm
Explanation:
From Rydberg equation;

where;
λ is the wavelength
n lines in the series
RH is Rydberg constant = 1.097 x 10⁷ m⁻¹
Also at a given maximum wavelength, we can determine the first line n₁ in the series


Given;
maximum wavelength = 656.46 nm

Now, test for different values of n that will be equal to 7.2
let n₁ = 1

n₁(1) ≠ 7.2
Again, let n₁ = 2

∴ n₁(2) = 7.2
For the least wavelength given as 410.29 nm, n = ?

next line in the series will be 7
The wavelength of next line in the series will be;

Therefore, the wavelength of next line in the series will be 397.05 nm
I think the answer is B but not too sure.
To develop this problem we require the concepts related to wavelength and its expression to calculate it.
The wavelength is given by

Where,
light velocity
f = frequency.
Our values are given by,



Then,
Visible
Gamma Ray
Infrared
<em>*Note the designation on the type of rays that are, can be found in consulted via On-line or in the optical books referring to the electromagnetic spectrum table with their respective ranges.</em>