Question

The earth rotates $360°$about its axis in about $24hours$. By how much degree will it rotate in $4hours$ ?

Answer 1

Given, the earth rotates $360°$about its axis in about $24hours$ i.e.

Rotation by the earth in $24hours$ $=360°$

Using the unitary method in which first we find the value of one unit and then the value of the required number of units.
Rotation by the earth in $1hour$$=\frac{360°}{24}=15°$
$\therefore$Rotation by the earth in $4hours$$=15°\times 4=60°$
Hence, the Earth will rotate by $60°$ in $4hours$.