Advertisements
Advertisements
Question
What must be the radius of a circular running path, around which an athlete must run 5 times in order to describe 1 km?
Solution
Let the radius of the circular path be = r m.
Length of the circular path s = 1 km
s = 1000 m.
Athlete runs 5 times around the path to cover 1 k. m distance
∴ θ = 360° × 5
θ = 360° × 5 × `pi/180` radians
θ = 10 π radians
s = r θ
1000 = r 10 π
r = `1000/(10pi)`
r = `(1000 xx 7)/(10 xx 22) = 350/11`
r = 31 .818 meters
Radius of the circular path = 31 .82 meters
APPEARS IN
RELATED QUESTIONS
Express the following angles in radian measure:
– 205°
Express the following angles in radian measure:
150°
Express the following angles in radian measure:
330°
Find the degree measure corresponding to the following radian measures
`pi/3`
Find the degree measure corresponding to the following radian measures
`pi/9`
Find the degree measure corresponding to the following radian measures
`(2pi)/5`
Find the degree measure corresponding to the following radian measures
`(7pi)/3`
Find the degree measure corresponding to the following radian measures
`(10pi)/9`
In a circle of diameter 40 cm, a chord is of length 20 cm. Find the length of the minor arc of the chord
What is the length of the arc intercepted by a central angle of measure 41° in a circle of radius 10 ft?
If in two circles, arcs of the same length subtend angles 60° and 75° at the centre, find the ratio of their radii
The perimeter of a certain sector of a circle is equal to the length of the arc of a semi-circle having the same radius. Express the angle of the sector in degrees, minutes and seconds
An airplane propeller rotates 1000 times per minute. Find the number of degrees that a point on the edge of the propeller will rotate in 1 second
A train is moving on a circular track of 1500 m radius at the rate of 66 km/hr. What angle will it turn in 20 seconds?
A circular metallic plate of radius 8 cm and thickness 6 mm is melted and molded into a pie (a sector of the circle with thickness) of radius 16 cm and thickness 4 mm. Find the angle of the sector.
Choose the correct alternative:
A wheel is spinning at 2 radians/second. How many seconds will it take to make 10 complete rotations?
