Top answers

What's the difference between Potential Difference and Electromotive Force

Although both are measured in volts, there is a subtle difference in their respective definition. Electromotive Force is the transfer of chemical energy in a battery (multiple single cells) into electrical e...
JJ
Answered by Joseph J. • Physics tutor
4601 Views

Why does Lenz's law have a minus sign?

The minus sign shows that the direction of induced current always opposes the change that created it. So when certain metals are cropped through say a copper tube they slow down. Show video of Lenz's law in ...
JJ
Answered by Joseph J. • Physics tutor
2413 Views

Sphere A (mass m), moving with speed 3v, collides with sphere B (mass 2m) which is moving in the opposite direction with speed v. The two spheres then combine, calculate the resulting velocity of the combined spheres.

Sphere A has mass m and velocity +3v so its initial momentum is 3mv. Sphere B has mass 2m and velocity -v so its initial momentum is -2mv. Therefore we can say:3mv - 2mv = M c v c , where M c and v c are the...
TS
Answered by Ted S. • Physics tutor
3180 Views

Why is it important that the baryon and lepton numbers of an interaction are conserved?

Conservation Laws are useful because they establish fixed rules that physical interactions must follow, which helps physicists to better understand these processes. In particular, they provide a picture of w...
TS
Answered by Ted S. • Physics tutor
3899 Views

What is EMF? How do we test for it?

Electromotive Force (EMF) is the measure of how much energy a source like a battery gives to the charges in a circuit. As with most things, this energy source is not 100% efficient, and has an associated int...
KM
Answered by Kieran M. • Physics tutor
4822 Views