Hey bradyc12.

For Q2 you have to use the parameterization where ds^2 = dx^2 + dy^2 + dz^2. Now divide by dt^2 and take a square root to give you:

(ds/dt) = SQRT((dx/dt)^2 + (dy/dt)^2 + (dz/dt)^2).

Remember that the key thing with arc-length is that you finding infinitesimals of pythagoras' theorem where you are adding up the hypotenuses to get the final arc-length.