Top answers

Why is the index of refraction important for light passing between two materials?

It's important information as it tells you how fast light travels through the material. This can give you an insight into how the angle of refraction of the light is related to the angle of incidence at the ...
OP
Answered by Oliver P. • Physics tutor
2533 Views

Why does the equation for gravitational potential energy give a negative value if energy cannot be negative.

The equation is shown below as found in the IB Physcis Data Booklet. GPE = -G M m / r Where GPE is gravitational potential energy, G is the gravitational constant, M and m are the masses of the objects, and ...
WL
Answered by William L. • Physics tutor
6155 Views

Tritium is a radioactive nucleide with a half life of 4500 days, determine the time for 90% of it to decay.

We know that the number of undecayed nuclei, N, is given by N=N 0 e -lambda t . From this, by setting N=N 0 /2 we know at this point that t= T 0.5 (the half life) and can show that lambda =ln(2)/T 0.5 . Henc...
LC
Answered by Luke C. • Physics tutor
3897 Views

How does an object in circular motion experience acceleration when it is going at a constant speed?

Acceleration is defined as the rate of change of velocity. The important thing to realise here is that velocity is a vector quantity while speed is a scalar one. An object going in circular motion has consta...
LK
Answered by Loukas K. • Physics tutor
4995 Views

How do current and voltage vary in series and parallel circuits, respectively?

In a series circuit, the current is the same throughout; the voltage is split among the components (such as LEDs or resistors) in proportion to the resistance of the components (higher resistance means more ...
PM
Answered by Paul M. • Physics tutor
14802 Views