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What is the standard model?

The standard model is a 'catalogue' of subatomic particles (the smallest building blocks of everything in the universe). It categorises these subatomic particles based on their properties and has predicted t...
SL
Answered by Scott L. • Physics tutor
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What is the Centripetal force, and how does it keep objects in circular motion?

The Centripetal Force is not a new force which begins to act on an object as it moves in a circle. It is in fact the result of an imbalance of the forces acting on an object i.e the net force. This net force...
SB
Answered by Shaurya B. • Physics tutor
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Uranium -238 has a half life of 4.5 billion years. How long will it take a 2g sample of U-238 to contain just 0.4g of U-238?

Radioactive decay is a process where the nucleus of an unstable atom, such as Uranium-238 loses energy by emitting radiation. The half life is the average time it take for half the nuclei in a sample to unde...
RE
Answered by Robert E. • Physics tutor
15321 Views

What is escape velocity?

This is the minimum initial velocity required to move from a point to infinity in a gravitational field. Infinity is defined to have a potential, V of zero; this is the point where the gravitational field ha...
AP
Answered by Ashkan P. • Physics tutor
8356 Views

Derive the escape velocity from the surface of a planet with radius, r, and mass, M.

This question is about converting kinetic energy into gravitational potential energy. Escape velocity is the speed required to leave the gravitational field of a mass, in this case it's a planet. In other wo...
TR
Answered by Thomas R. • Physics tutor
22418 Views