Question

4. The second needle of a clock is 7 cm. How much distance is covered
by its outer edge in 24 hours?
(Hint: there are 1440 minutes in a day and night)​

Answer 1

Answer:

63360 cm

Step-by-step explanation:

find the circumference using 2πr

u will get 44cm

multiply that by 1440 u GT the required answer

Answer 2

Step-by-step explanation:

When you said, seconds hand has a length of 10 cm, that means the seconds hand rotates along the circle with a radius of 10cm.

So, in 15 seconds, it travels quarter of the circle or 90 degrees. Forming a right isosceles triangle with sides of 10 cm and an unknown Hypotenuse x.

Using Pythagorean Theorem,

x^2 = 10^2 + 10^2 [Side^2 + Side^2 = Hypotenuse^2]

x = 10 Sqrt(2) = 14.1421 cm

Distance is the actual distance traveled through the path taken. And Displacement is the distance in the shortest path.

So distance traveled by seconds hand is the perimeter/4 = 2(Pi)*Radius/4

= 2 (3.1415)*10/4 = 5*3.1415 = 15.7075 cm

And Displacement = 14.1421 cm