Answer:
572.3 nm
Explanation:
= refractive index of the oil film = 1.48
= thickness of the oil film = 290 nm
= wavelength of the dominant color
m = order
Using the equation

For m = 0

= 1716.8 nm
For m = 1

= 572.3 nm
For m = 2

= 343.4 nm
Hence the dominant color wavelength is 572.3 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
Velocity = displacement (distance)/time
v=80m/4s
v=20m/s
velocity = 20 meters per second
I think the correct answer would be that because electromagnets are powerful and can be turned off and on anytime. Electromagnet is a magnet in which the magnetic field is made by the electric current that is induced to the system.
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).