Question

An athlete runs along a circular track of radius 100m . Calculate the displacement of the athlete and the distance travelled by him When he covers 3/4th of the track CBSE board

Answer 1

Answer:

distance = 471 metre, displacement = 100*2^1/2

Explanation:

first find the circumference of the circle and take pie as 3.14 so,

circumference = 2*3.14*radius

                         = 2*100*3.14

                         = 628 metre

when the athlete covers 3/4 of the track then its,

distance is,

3/4* circumference of circle

= 3/4 * 628

= 471 metre

displacement is,

for finding the dispalcement we will have to divide the circle into four equal parts and then form a right angled triangle in each of those parts,

then we will have a chord having unknown length as our hypotenuse and the height and base of our triangle will be the radius of the circle i.e. 100 metre

by pythagoras theorem,

(base)^2 + (height)^2 = (hypotenuse)^2

(100)^2 + (100)^2 = (hypotenuse)^2

therefore, hypotenuse = 100*2^1/2

i would have explained it more clearly on a paper

well hope it helps!!