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?
Advertisements
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
A room 4.9 m long and 3.5 m board is covered with carpet, leaving an uncovered margin of 25 cm all around the room. If the breadth of the carpet is 80 cm, find its cost at ₹ 80 per metre.
In the following figure, the square ABCD is divided into five equal parts, all having same area. The central part is circular and the ines AE, GC, BF and HD lie along the diagonals AC and BD of the square. If AB = 22 cm, find:
the circumference of the central part.
Write the area of the sector of a circle whose radius is r and length of the arc is l.
In a circle of radius 10 cm, an arc subtends an angle of 108° at the centre. what is the area of the sector in terms of π?
The area of a circular path of uniform width h surrounding a circular region of radius r is
Find the area of the shaded region in the given figure, where a circular arc of radius 6 cm has been drawn with vertex of an equilateral triangle of side 12 cm as centre and a sector of circle of radius 6 cm with centre B is made.
In the given figure, O is the centre of the circle with AC = 24 cm, AB = 7 cm and ∠BOD = 90°. Find the area of shaded region.
A circular disc of radius 6 cm is divided into three sectors with central angles 90°,120° and 150°. What part of the whole circle is the sector with central angle 150°? Also, calculate the ratio of the areas of the three sectors.
A square tank has an area of 1600 cm2. There are four semicircular plots around it. Find the cost of turfing the plots at Rs 12.50 per m2
Find the diameter of a circle whose area is equal to the sum of the areas of the two circles of radii 24 cm and 7 cm.
