Question

approximate average speed of the hour hand of a clock.if its length is 100mm

Answer 1

Answer:

We know,

Speed =

Time

Distance

Here distance will be the circumference of the circle that second-hand makes in one complete revolution. Therefore, Distance = 2πr(circumference)

r (radius) = 10 cm (length of second hand)

Distance =2×3.14×10cm

Distance = 62.8 cm

Now, the time it takes to complete one full revolution by second hand = 60 seconds

Speed =

60

[62.8cm]

seconds

Speed = 1.0466

second

cm

Therefore, Speed of the tip of 10 cm long second hand of a clock is 1.0466

second

cm

Answer 2

As We know that  

Speed =$\frac{distance}{time}$

so here  distance will be the circumference of the circle that second-hand makes in one complete revolution.

Therefore,

formula : Distance = 2πr

given :

r  = 100 mm length

convert 100 mm  into Cm i.e 10 cm

Distance = 2 x 3.14 x  10  

Distance = 62.8 cm

the time it takes to complete one full revolution by second  = 60 sec.

Speed = $\frac{6.28}{60}$ seconds

Speed = $1.0466$ cm/second

Therefore, the Speed of the tip of the 10 cm long second hand of a clock is 1.0466 cm/second .