Advertisements
Advertisements
प्रश्न
A bicycle wheel, diameter 56 cm, is making 45 revolutions in every 10 seconds. At what speed in kilometre per hour is the bicycle traveling?
उत्तर
Diameter = 56 cm
∴ Radius, r = 28 cm
∴ Distance travelled in 1 revolution
i.e. circumference = `2pir = 2 xx 22/7 xx 28 = 176` cm
∴ Distance travelled in 45 revolution
= `176 xx 45 = 7920 "cm" = 7920/(100 xx 1000)`km
Time = 10 sec = `10/(60 xx 60)` hr.
Speed = `(7920/(100 xx 1000))/(10/(60 xx 60))`m
= `7920/(100 xx 1000) xx (60 xx 60)/10 = 28512/1000` km/hr
= 28.512 km/hr
APPEARS IN
संबंधित प्रश्न
The perimeter of a rectangular plot of land is 80 m and its breadth is 16 m. Find the length and area of the plot.
The area of a square filed is 8 hectares. How long would a man take to cross it diagonally by walking at the rate of 4 km per hour?
Find the area of the quadrilateral ABCD in which in AB=42 cm, BC=21 cm, CD=29cm, DA=34 cm and diagonal BD = 20 cm.
Prove that the area of a circular path of uniform width h surrounding a circular region of radius r is `pih(2r+h)`
In the following figure, shows the cross-section of railway tunnel. The radius OA of the circular part is 2 m. If ∠AOB = 90°, calculate:
the height of the tunnel
An arc subtends an angle of 90° at the centre of the circle of the radius 14 cm. Write the area of minor sector thus formed in terms of π.
The diameters of three circles are in the ratio 3: 5: 6. If the sum of the circumferences of these circles is 308 cm; find the difference between the areas of the largest and the smallest of these circles.
The circumference of a circular table is 88 m. Find its area.
The sum of the radii of two circles is 10.5 cm and the difference of their circumferences is 13.2 cm. Find the radii of the two circles.
The area of a circle is 154 cm2. Its diameter is ____________.
