Question 19M.2.SL.TZ1.d
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.SL.TZ1.d |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Determine | Question number | d | Adapted from | N/A |
A girl rides a bicycle that is powered by an electric motor. A battery transfers energy to the electric motor. The emf of the battery is 16 V and it can deliver a charge of 43 kC when discharging completely from a full charge.
The maximum speed of the girl on a horizontal road is 7.0 m s–1 with energy from the battery alone. The maximum distance that the girl can travel under these conditions is 20 km.
The bicycle and the girl have a total mass of 66 kg. The girl rides up a slope that is at an angle of 3.0° to the horizontal.
The bicycle has a meter that displays the current and the terminal potential difference (pd) for the battery when the motor is running. The diagram shows the meter readings at one instant. The emf of the cell is 16 V.
Determine the internal resistance of the battery.
[2]
V dropped across battery OR Rcircuit = 1.85 Ω ✔
so internal resistance = = 0.62«Ω» ✔
For MP1 allow use of internal resistance equations that leads to 16V − 12V (=4V).
Award [2] for a bald correct answer.
