What is the correct definition of speed.
distance (miles or meters)
time per distance (hours per mile or seconds per meter
distance per time (miles per hour or meters per second)
time (hours or seconds)

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.