Answer:
0.714 m
Explanation:
From the question,
v = λf......................... Equation 1
Where v = velocity of visible light, f = frequency of visible light, λ = wave length of visible light.
make λ the subject of the equation
λ = v/f.................. Equation 2
Given: f = 4.2×10⁸ Hz
Note: Light is an electromagnetic wave, and all electromagnetic waves travels with the same speed (3×10⁸ m/s)
Constant: v = 3×10⁸ m/s
Substitute these values into equation 2
λ = 3×10⁸/4.2×10⁸
λ = 0.714 m
The question is poorly worded, and makes it harder for the student to learn the basics of the subject. "Potential Difference" is the difference in electrical potential between two places in an electric field ... not in electrical potential energy.
Answer:
540 nm
Explanation:
According to the question,
The refractive index of the soap bubble, 
.
The thickness of the soap bubble wall is, 
.
Now, for constructive interference of soap bubble.
.
Now for first order m=1.
Therfore,
Substitute all the variables in the above equation.
.
Therefore,
.
Therefore the visible light wavelength which is strongly reflected is 540 nm.
Potential energy is defined by formula
here
m = mass
g = acceleration due to gravity
h = height
Now here two different stones are located at same height
while mass of stone A is twice that of stone B
so here we can say potential energy of A is
Similarly potential energy of B is
now if we take the ratio of two energy
so we can say potential energy of stone A is two times the potential energy of B
From the equations of linear motion,
v² = u² + 2as where v is the final velocity, u is the initial velocity and a is the gravitational acceleration, and s is the displacement,
Thus, v² = u² -2gs, but v=0
hence, u² = 2gs
= 2×9.81×0.43
= 8.4366
u = √8.4366
=2.905 m/s
Hence the initial velocity is 2.905 m/s
Then using the equation v= u +gt .
Therefore, v = u -gt. (-g because the player is jumping against the gravity)
but, v = 0
Thus, u= gt
Hence, t = u/g
= 2.905/9.81
= 0.296 seconds
