Question

An Athlete Runs two and half round on circular track.Find distance and displacement.Radius is 140m

Answer 1

$\huge\underline\mathbb\pink{Answer-}$

$</p><p>point\:A = starting\: point.\\ \\ \\</p><p>point\: B= ending \: point.\\ \\ \\</p><p>distance = \\ \\ \\</p><p>cirumference= 2πr\\ \\ \\</p><p>2 \:rounds= 2× 2πr\\ \\ \\</p><p>= 4πr\\ \\ \\</p><p>4× \frac{22}{7} × 140\\ \\ \\</p><p>= 4×22×20= 1760m\\ \\ \\</p><p>for\: \frac{1}{2}\:round- \\ \\ \\</p><p>\frac{circumference}{2}= \frac{2πr}{2}\\ \\ \\</p><p>= πr</p><p>= \frac{22}{7}× 140= 440m\\ \\ \\</p><p>total \:distance = 1760+440= 2200m\\ \\ \\</p><p>displacement = \\ \\ \\</p><p>after \: two \:rounds\: it \: will\: be \\ \\ \\</p><p>in\: same \: position.\\ \\ \\</p><p>shortest\: distance \: between \: point\\ \\ \\ A and \: B \:is \: diameter.\\ \\ \\</p><p>diameter= 2\: r\\ \\ \\</p><p>therefore\: displacement= 2\:r= 2×140\\ \\ \\</p><p>= 280m.$

Answer 2

Answer:

Explanation:

RADIUS OF THE TRACK = 140 M

CIRCULAR TRACK IMPLIES DISTANCE COVERED IN ONE ROUND EQUALS THE CIRCUMFERENCE OF THE TRACK.

COMPLETES 2 AND 1/2  ROUND IMPLIES

DISTANCE TRAVELLED = 2*2πR+2πR/2

[ IN THE SECOND HALF THE DISTANCE TRAVELLED IS EQUAL TO THE DISTANCE BETWEEN TO OPPOSITE POINTS IN THE TRACK ALONG THE CIRCUMFERENCE]

DISTANCE TRAVELLED = 4 π R+π R

                                        = 5 π R

                                        = 5*3.14*140

                                        = 2,198 M

DISPLACEMENT = SHORTEST DISTANCE BETWEEN THE FINAL AND INITIAL POSITION

WHILE COMPLETING THE TWO FULL CIRCLES THE ATHLETE COMES BACK TO THE SAME INITIAL POSITION

THAT IS THE INITIAL AND FINAL POSITION OF THE ATHLETE THE END OF TWO CIRCLES IS THE SAME AND THE DISPLACEMENT IS ZERO

IN THE JOURNEY THROUGH THE HALF CIRCLE , HE / SHE COMES TO THE DIAMETRICALLY OPPOSITE POINT .

HENCE THE DISPLACEMENT  = DIAMETER = 2*R = 2*140=280 M

DISTANCE = 2,198 M

DISPLACEMENT = 280 M.

HOPE THIS HELPS.