Answer:
v = 1.2 m/s
Explanation:
The wavelength of the waves is given as the horizontal distance between the crests:
λ = wavelength = 5.5 m
Now, the time period is given as the time taken by boat to move from the highest point again to the highest point. So it will be equal to twice the time taken by the boat to travel from highest to the lowest point:
T = Time Period = 2(2.3 s) = 4.6 s
Now, the speed of the wave is given as:

where,
v= speed of wave = ?
f = frequency of wave = 
Therefore,

<u>v = 1.2 m/s</u>
Answer:
a)
s
b) 3.41 mm
Explanation:
a)
We take the speed of light, c =
m/s and the refractive index of glass as 1.517.
Speed = distance/time
Time = distance/speed
Refractive index, n = speed of light in vacuum / speed of light in medium






b)
We take the refractive index of water as 1.333.
Speed in water = speed in vacuum / refractive index of water
Distance = speed * time



d = 3.41 mm
I'm not exactly sure but I'm thinking that it's the last one. Sorry if I'm wrong
Answer:
False
Explanation:
As we know that, the Balmer series gives the n values as,
.
.
Now the value of wavelength can be calculated as,
.
Here,
.
And
.
Now,
.
Therefore,

Therefore, the wavelength of Balmer series lies in visible region which is 547 nm.
In an alpha decay, an atom emits an alpha particle. An alpha particle consists of 2 protons and 2 neutrons: this means that during this kind of decay, the original atom loses 2 protons and 2 neutrons from its nucleus.
This also means that the atomic number Z of the element (the atomic number is the number of protons in the nucleus) decreases by 2 units in the process, while the mass number A (the mass number is the sum of the number of protons and neutrons) decreases by 4 units.