Question

$\ \textless \ br /\ \textgreater \ \huge\mathbb\purple{BONJOUR}$
An athlete completes one round of a circular track of diameter 200m in 40 s. what will the distance covered and the displacement at the end of 2 m 20 s.
$\huge\mathbb\pink{thanks in advance}$​

Answer 1

Answer:

Explanation:

Diameter = 200m

Radius = 100m

Time of one rotation = 40s

Time after 2m 20 s =  140 s

Displacement after 2 m 20 s i.e. in 140 s

Since,rotatin in 40 s = 1

Therefore, rotation in   1 s  =  1/ 40

∴ rotation in   140 s  =  1/ 40  ×  140

                              = 3.5

Distance covered in 2 m 20 s = circumference of circle × no of rotations

                                                  =  2πr × 3.5

                                                 = 2 × 3.14×100×3.5

                                                 = 2198m

Therefore, in 3.5 rotations athlete will be just at the opposite side of the circular track, i.e. at a distance equal to the diameter of the circular track which is equal to 200 m.

hence, displacement after 2 m 20 s = 200m

hope it helps

kindly mark it brainliest.

Answer 2

length AB=200m=2R

time taken to complete one round=40 sec

let the starting point be A

in 140 sec or 2 min 20 sec number of rounds completed=14040=3.5

distance traveled=3.5 * (2*π*R)=3.5*2*π*100 m=2200 m (approx)

displacement refers to change in position from the starting point.the final point is B

as after 3.5 revolutions(starting from A) the athlete will be at B.

displacement=200m