A displacement sensor records the motion of one point on a metal rod as a wave passes. The readings are shown in the table.
| Time / s | Displacement / mm |
|---|---|
| 0.00 | 0.0 |
| 0.10 | +2.0 |
| 0.20 | 0.0 |
| 0.30 | -2.0 |
| 0.40 | 0.0 |
| 0.50 | +2.0 |
| 0.60 | 0.0 |
The displacement varies from +2.0 mm to -2.0 mm, a total range of 4.0 mm. Which pair gives the period and amplitude of the wave at the sensor?
0.60 s0.60\ \mathrm{s}0.60 s and 2.0 mm2.0\ \mathrm{mm}2.0 mm
0.40 s0.40\ \mathrm{s}0.40 s and 4.0 mm4.0\ \mathrm{mm}4.0 mm
0.20 s0.20\ \mathrm{s}0.20 s and 2.0 mm2.0\ \mathrm{mm}2.0 mm
0.40 s0.40\ \mathrm{s}0.40 s and 2.0 mm2.0\ \mathrm{mm}2.0 mm