Kognity IB Physics A.0 Measurements & Uncertainty (id: 43662a57a)

[单选题]
By approximately how many powers of ten is the height of a humal:r pv+yut:f0gepe9j 5k4n 4an larger tl v1 tg4yiq ;w:fsba+7han the height of a graiylv+t :b g7fi ;wq4s1an of sand?

A. -3
B. 2
C. 3
D. 1000


参考答案:  C


本题详细解析:
A grain of sand is about a 1-3 millimetre long while human beings are - dg6s g8g9z;s8 nrtrukz(3 laabout $2 \mathrm{~m}$ tall (very roughly!). So: $\frac{\text { height of human }}{\text { size of a grain of sand }}=\frac{2 \mathrm{~m}}{0.002 \mathrm{~m}} \approx 1000$ So we are about $1000=10^3$ times taller than a grain of sand. If you chose #2, this answer implies that a human is $10^{1000}$ times bigger than a grain of sand. This is a huge number!