Question

A wheel of a cycle with diameter 56 takes 45 revolutions in 10 sec what is th speed of the cycle in km/hr

Answer 1

Diameter = 56 cm
radius = D / 2 = 28 cm
no. of revolutions (n) = 45
time ( t) = 10 sec
revolutions per second = 45 / 10 = 4.5 revolutions per second
Distance(D) covered per second = Perimeter of the wheel × 4.5
Speed = Distance / Time
S = 2πr × 4.5
⇒ S = 176 cm × 4.5 per sec
⇒ S = 1.76 metre × 4.5 per sec
⇒ S = 7.920 metre/sec