Question

an athlete completes one round of a circular track of diameter 200m in 40 seconds.

Answer 1

Answer:

if u r looking for the speed or velocity of athlete probably, that would be

d= 200m

r= 100m

time= 40 seconds

total distance= 2πr

= 628.5 m. in 40 sec

so uniform velocity will be 942.8 metre/min. or 15.7 m/s.

Answer 2

➝ Solution :-

Time taken :- $140$ $seconds$

Radius (r) :- $100$ $metres$

$\underline\text{In\:\:40s\:\:the\:\:athlete:\:complete:\:one\:\:round:-}$

$\underline\text{so\:\:in\:\:140s\:\:athlete:\:will:\:complete:-}$ :-

➝$\frac{1400}{40}$

➝$3.5$ $rounds$

➝ Distance covered :-

➝ $2πr$ $×$ $3.5$

➝ $2$ $×$ $\frac{22}{7}$ $×$ $100$ $3.5$

➝ $2200m$

➝ At the end of his motion ,the athlete will be in the diametrically opposite position

➝$Displacement$ $=$ $Diameter$ $=$ $200m$

➝ $\frac{v^{2}-u}{2a}^{2}$

➝ $\frac{0^{2}-2}{2(-0.5)}^{2}$

➝ $625m$

∴ train will go 625 m before it brought to rest