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

[单选题]
By approximately how many powers of te3seeh)n; zcla dht8 ,i81dk(lve a /9rn is the height svv lr2svv3z k*c)+9fof a human larger than the height ofv2 )v9+vz*srsv 3 lckf a grain 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 a* 5f)pvqs8s1zwe auu0re about $2 \mathrm{~m}$ 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!