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Explain the photo-electric effect and how the particle theory of light explains the phenomena. State the equation used to the determine the kinetic energy of a photo-electron and explain the origin of the terms used in your equation.

The photoelectric effect is the stimulated emission of electrons due to the irradiation of photons onto the surface of a metal. The increase in the frequency of the photons doesn’t lead to an increase in the...
JG
Answered by Joseph G. • Physics tutor
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The radius of the Earth is 6,400km and has a mass of 6x10^24kg. Calculate the minimum velocity needed by a projectile, fired from the surface of the Earth in order to escape the Earths gravity.

First we write down the relevant information given in the question. R e = 6,400km = 6.4 x 10 6 m, M e = 6 x 10 24 kg.For the projectile to escape the Earths gravity, the projectile must be launched with a ki...
NC
Answered by Neil C. • Physics tutor
8053 Views

explain how a cyclotron produces a high energy electron

-cyclotron consists of 2 dees connected to an AC power supply. When an electron is released from a source in the centre of the cyclotron, it is initially attracted towards the positively charged dee, due to ...
TS
Answered by Toby S. • Physics tutor
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A fluorescent light uses a lining to emit visible light, explain why this is necessary and how it works.

The vapour inside a fluorescent tube is excited and ionised by the electrode either end of the tubes. The excited electrons inside of the vapour are unstable and so decay into lower energy states. The differ...
MC
Answered by Monty C. • Physics tutor
2649 Views

Find an expression for the escape velocity of a test object.

Escape velocity is the velocity required to just escape the gravitational pull of a body. The gravitational force of a body is given by Newtons Law: F = GMm / r 2 (where G is the gravitational constant, M is...
CN
Answered by Ciara N. • Physics tutor
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