Question

The mass of a solid iron cube of side 3 cm is to be determined using a spring balance. If the density of iron is approximately 8.5 g/cm³, the best-suited spring balance for determining weight of the solid would be of

• A. range 0-250 gwt; least count 1 gwt
• B. range 0-250 gwt; least count 5 gwt
• C. range 0-1000 gwt; least count 5 gwt
• D. range 0-1000 gwt; least count 10 gwt

Answer 1

The correct option is B

range 0-250 gwt; least count 5 gwt

Edge = 3 cm, Density = $8.5g/c{m}^3$,
Mass = density $\times$ volume $=8.5\times (3\times 3)=229.5gwt$
Therefore, second spring balance of range 0-250 gwt with least count 5 gwt will be suitable.