Question

a bicycle wheel of radius 35cm is making 25 revolutions in 10 seconds. at what speed in km/hr is the cycle moving.

Answer 1

distance=2πr*revolution
=2*22/7*35*25
=5500cm
=55m
speed=55/10*18/5
=19.8km/h

Answer 2

Answer:

19.8 km/hr.

Step-by-step explanation:

Radius of wheel = 35 cm

Circumference of wheel = $2\pi r$

                                        = $2 \times \frac{22}{7} \times 35$

                                        = $220$

Thus distance traveled in 1 revolution is 220 cm.

So, Distance traveled in 25 revolution = $220 \times 25$

                                                                = $5500$

So, it travels 5500 cm = 55 m in 10 seconds

Speed= $\frac{Distance}{Time}$

          = $\frac{55}{10}$

          = $5.5 m/sec$

1 m/s = 3.6 km/hr

So, 5.5m/s= $5.5 \times 3.6=19.8 km/hr$

So, Speed of cycle in km/hr is 19.8 km/hr.