JAMB - Physics (2019 - No. 52)
When a girl moves towards a plane mirror at a speed of 4.0m/s, the distance between the girl & her image reduces at a speed of
2 m/s
4 m/s
8 m/s
12 m/s
คำอธิบาย
| v | = | d
t |
or | v | α | d |
d = x, v = 4m/s
d = 2x, v = ? (girl & image)
| v | = | 2 × 4
x |
= | 8 | m
s |