The radius of a wheel is 35 cm and it takes 5 minutes to make 250 rotations .find the speed of the wheel in km per hour ?
Answers
Answer:
Radius = 35 cm
Circumference = 2πr = 2 ×22/7×35 = 220 cm
5 min -- 250 rotations
So, 0.8333 rotation = 1 seconds
So , speed = 0.833*220 cm/s = 183.26 cm/s
= 659736 cm / hr (*3600)
= 6.59736 km/hr
Step-by-step explanation:
The speed of the wheel is 16.5 km/hr.
Explanation:
The radius of the wheel is 35 cm.
∴ Circumference of the wheel = 2πr
= 2×(22/7)× 35
= 44×5
= 220 cm
In 1 rotation it covers a distance of 220 cm.
∴ In 250 rotations it covers a distance of = (220×250) cm
= 55000 cm.
= (55000/100) m [∵1m = 100 cm]
= 550 m
1 minute = 60 seconds
∴ 5 minutes = (60×5) seconds
= 120 seconds
∴ According to problem,
Time taken by the wheel = 120 seconds
Distance covered = 550 m
∴ Speed = distance/time
= (550/120) m/s
= 4.58333333 m/s
= 4.6 m/s
Hence the speed in km/hr = (4.6× 18/5)
= 16.5 km/hr.
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