[填空题]
The density of a solinin604- am1sz b7cf azd sphe06 4-gn*mah(z, g iozzvtj2dzxm.,m wre is measured with percentage uncertainty of 5%. The radius of the sphere is 4.0 ± 0.2 cm. What is the percentage uncertainhtz6-xm .v,nw 0 gzm2ag*,z(domzij 4 ty in the mass of the sphere? % (Please do not include the % simbol in the blank)
参考答案: 20.0
本题详细解析: The mass of the sphere can be calculated by multiplyi 2wjlgy-/k,ryng its volume by the density of the material of which it 2l-yj ,wky/ rgis made: $$M=\frac{4}{3} \pi r^3 \rho$$ so the percentage uncertainty in $M$ is $$\frac{\Delta M}{M}=3 \frac{\Delta r}{r}+\frac{\Delta \rho}{\rho} .$$ The percentage uncertainty in $r$ is $5 \%$, so the percentage error in $M$ is $(3 \times 5 \%)+5 \%=20 \%$
Post time 2024-8-21 21:38:19