The potential difference does work on the electron. The work is given by:
W = Vq
W = work, V = potential difference, q = electron charge
Given values:
V = 6V, q = 1.6x10^-19C
Plug in and solve for W:
W = 6(1.6x10^-19)
W = 0.96aJ
This is best explained through the use of an optics diagram, this is a little too complicated to explain in a short answer, and as I can't draw an appropriate diagram in this answer, I will point you to this excellent resource which explains what you have asked very well!
Go onto the BBC website (you should have access to it even if you aren't in the UK) and paste this after the BBC url,
/bitesize/intermediate2/physics/waves_and_optics/image_formation_from_lens/revision/1/
When you sweat due to heat your sweat evaporates off your body taking the heat away
almost everything artafitial would have been made because of science. However nothing natural would exist because of science. All science does is look around and see what's up.
Answer:
1. Torque → F. Study of forces
2. C.O.G → D. Point of action of weight.
3. Plumb line → A. Line of C.O.G
