Advertisements
Advertisements
प्रश्न
An express train is running between two stations with a uniform speed. If the diameter of each wheel of the train is 42 cm and each wheel makes 1200 revolutions per minute, find the speed of the train.
उत्तर
radius of the wheel = `42/2` = 21 cm
Circumference of the wheel = 2π x 21 = 132 cm
Distance travelled in one minute
= 132 x 1200
= 158400 cm
= 1.584 km
Hence the speed of the train
= `[1.584 "km"]/[1/60"hr"]`
= 95.04 km/hr.
APPEARS IN
संबंधित प्रश्न
In Figure, find the area of the shaded region [Use π = 3.14]
In Fig 4, a circle is inscribed in an equilateral triangle ABC of side 12 cm. Find the radius of inscribed circle and the area of the shaded region.[Use π=3.14 and √3=1.73]
How many times a wheel of radius 28 cm must rotate to go 352 m? (Take `pi = 22/7`)
Find the circumference and area of circle of radius 4.2 cm
Find the area of the circle if its circumfence is 88 cm.
Find the area and perimeter of the following sector :
Diameter = 42 cm, angle at the centre is 100·.
If the perimeter of a semi-circular protractor is 36 cm. Find its diameter.
The speed of a car is 66km per hour. If each wheel of the car is 140cm in diameter, find the number if revolution made by each wheel per minute.
The circumference o a garden roller is 280cm. How many revolutions does it make in moving 490m?
The numerical value of the area of a circle is greater than the numerical value of its circumference. Is this statement true? Why?
