Speed= distance/time
Speed= 150000m/7200s=20.83m/s(cor.to.2d.p.)
The headlamp's concave mirror is open on one end, and the light bulb's filament is placed at or near the focus. (Sorry if this is Wrong)
Answer:

Explanation:
In series combination, the equivalent resistance is given by :

Let the identical resistors be R. We have, 
So,

So, the resistance of each resistor is
.
Resistance is the ratio of
(voltage between two points in the circuit)
divided by
(current between the same points).
It's expressed in units of Ohms, so the correct choice is "none of the above".