The table shows the object distance, u, and the corresponding image distance v, for an object placed in front of a concave mirror.
u (cm) | 20 | 25 | 30 | 40 | 50 | 70 |
v(cm) | 20 | 16.7 | 15 | 13.3 | 12.5 | 11.6 |
1/u (cm−1) | | | | | | |
1/v (cm−1) | | | | | | |
- Complete the table by filling in the values of 1/u and 1/v
- plot a graph of 1/u (y-axis) against 1/v (x-axis)
- From the graph, determine the focal length of the mirror.