WAEC - Physics (2015 - No. 30)
A girl standing some distance from the cliff claps her hands and hears the echo 0.8s later. calculate her distance from the cliff. [speed of sound in air = 320 ms-1]
23m
128m
288m
298m
Giải thích
V = \(\frac{2nx}{E}\)
= \(\frac{2 \times 1 \times X}{0.8} = 320\)
2x = 0.8 x 320
x = \(\frac{0.8 \times 320}{2}\)
= 128m
= \(\frac{2 \times 1 \times X}{0.8} = 320\)
2x = 0.8 x 320
x = \(\frac{0.8 \times 320}{2}\)
= 128m