[填空题]
The density of a solid sphere is measured w*/wzg;eg.a q aith percentage unc;-c pnp1e7w)tj k(lyj bb7yvlog8g ;7ertainty of 5%. The radius of the sphere is 4.0 ± 0.2 cm. What is the percentage uncertainty in the mass of the sphej;c-y(l17yb 7;8l ne)gbvkwgo t7p pj re? % (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 iwo p(c:h6j5lmultiplying its volume by the density of lj 6op wci(h5:the material of which it is 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