Answer:
Frequency, 
Explanation:
Visible red light has a wavelength of 680 nanometers (6.8 x 10⁻⁷ m). The speed of light is 3.0 x 10 ⁸ m / s. What is the frequency of visible red light?
It is given that,
Wavelength of a visible red light is, 
Speed of light is, 
We need to find the frequency of visible red light. It can be calculated using below relation.

So, the frequency of visible red light is
.
Answer:
d)
Explanation:
Electrons are lost or gained when the ballon is rubbed with a PVC. As the rubber ballon lost electrons, it will have more protons, hence the positive charge. (More protons than electrons in the ballon).
Answer:
8.40 m/s
Explanation:
Slope of the plot is 0.119
Slope of a plot is given by the change in y direction divided by the change in x direction
Here, the y axis represents inverse wavelength and the x axis represents frequency.
f = Frequency (Hz, assumed)
v = Phase velocity (m/s, assumed)
λ = Wavelength (m, assumed)
So, slope

Now,


The speed of sound travelling in the tube is 8.40 m/s
Answer:
14 m/s
Explanation:
u = 0, h = 10 m, g = 9.8 m/s^2
Use third equation of motion
v^2 = u^2 + 2 g h
Here, v be the velocity of ball as it just strikes with the ground
v^2 = 0 + 2 x 9.8 x 10
v^2 = 196
v = 14 m/s