Answer: the minute hand travel 39.6 cm
Step-by-step explanation:
Length of minute hand of a clock = 9 cm
Central angle made by the minute hand = 252°
To find: how far the minute hand travel
Therefore
Length of minute hand is equal to the radius of circle
As we know the circumference of a circle is given by
[tex]C= 2\pi r \dfrac{\theta}{360^\circ}[/tex] where C is circumference , r is radius and ∅ is the central angle
So we have
[tex]C= 2 \times \dfrac{22}{7} \times 9 \times \dfrac{252^\circ}{360^\circ} \\\\\Rightarrow C= 2 \times \dfrac{22}{7} \times \dfrac{252^\circ}{40^\circ} \\\\\Rightarrow C= \dfrac{11}{7} \times \dfrac{252^\circ}{10^\circ} = 39.6[/tex]
Hence, the minute hand travel 39.6 cm in 42 minute period
