Numerical Problems

Numerical Problems

* Look at a meter scale carefully and answer the following:

* How many mm are there in a cm?

Solution: 10 mm = 1 cm

* How many cm are there in a m?

Solution: 100 mm = l m

* Complete the following:

• 7875 cm = 78 m  75 cm

• 1195 m = 1 km 195 m

• 15 cm 10 mm = 160 mm

• 45 km 33 m = 45033 m.

A Quick Look

* The comparison of an unknown quantity with some known quantity is known as measurement.

* All physical quantities have standard units for the sake of uniformity.

* Length, mass and time are some of the fundamental physical quantities.

* The SI units for

Length - metre

Mass - kilogram

Time - second

Volume - litre (or) cm³

* While using ruler, the accurate measurement can be arrived by avoiding three types of possible errors.

* Volume of solids, liquids and regular objects is measured by direct measurement.

* Volume of irregular objects can be measured by water displacement method.

* Electronic balance is an instrument to provide accurate measurement of mass correct up to milligram.