Significant Figures — Prelims Questions

A student measures the length of a rod as $15.2,\text{cm}$ and its width as $2.5,\text{cm}$. What is the area of the rod, reported with the correct number of significant figures?

What is the number of significant figures in $0.005070,\text{kg}$?

Three measurements are taken: $12.5,\text{m}$, $1.25,\text{m}$, and $0.125,\text{m}$. What is their sum, reported with the correct number of significant figures?

The mass of an object is $4.237,\text{g}$ and its volume is $2.5,\text{cm}^3$. Calculate the density of the object to the correct number of significant figures.

Which of the following numbers has 5 significant figures?

A student measures the current as $0.50,\text{A}$ and the resistance as $12.3,Omega$. What is the power dissipated in the resistor, $P = I^2R$, reported to the correct number of significant figures?