Science Buddies: "Ask an Expert"

sir can you tell me the relation between time,resistivity and length
i got
t=Rl

Hello,

I'm not sure if this relates to a science project, but we may consider resistance across (for example) a wire,

R = p*L/A

where R is resistance, p is resistivity, L is length, and A is cross-sectional area. Expand all the units of these terms (e.g. R = ohm = kg*m^2/(s^3*A^2) )

If you like, from here, we may substitute this expression for R into V=IR

and note that I is current (Coulomb/second) and V = voltage (Joules/Coulomb.)

-John