Question

While measuring the area of the top surface of a rectangular piece of wood, a child measures the length using a ruler, accurate to 1 mm. He measures the width using a micrometer screw gauge which is accurate to 0.01 mm. But his teacher tells him that there is not point in measuring the width so accurately if the length is not accurate, Why does his teacher say so?

Answer 1

Answer:

To make accurate measurements you must use appropriate measuring instruments and also know how to use these instruments properly

Explanation:

Answer 2

Screw Gauge and Ruler

Explanation:

• The child uses a ruler to measure the length of a rectangle. It is given that ruler is accurate to 1mm where as he uses a micrometer screw gauge to measure the width accurate to 0.01mm.
• Screw Gauge is a more accurate method for measurement of dimensions as compared to a ruler. As mentioned the accuracy of both instruments varies manifold.
• So the length will not be measured as accurately as the width because width will have much less error ( a screw gauge is used ) . Ruler only shows accuracy of 1mm hence it will give more error.