IB HL Physics Time Dilation

The new HL Physics course includes special relativity for all students. Below is a tutorial sheet on time dilation.

1. Do moving clocks run slower?
2. Define proper time.
3. A particle has a lifetime of 2.0 µs in its rest frame. The particle moves at 0.8c relative to a laboratory. Find the lifetime of the particle according to an observer in the laboratory reference frame.
4. Two detectors in a laboratory are 20.0 cm apart. A particle moving at a constant speed of 0.9 c relative to the laboratory passes through the detectors. What is the time of passge between the detectors as measured in the reference frame of the particle?

IB Physics EMF of a cell

Which of the following is/are correct regarding the emf of a cell?

1. The voltage of the battery.
2. The potential difference across the terminals of the cell when zero current passes through it.
3. The work done in moving unit charge through the cell.
4. The work done in moving unit charge around the circuit.
5. The chemical energy changed to thermal energy when unit charge moves through the cell.
6. The power per unit current passing through the cell.