a man running around a circle track of radius 20m covers one complete round in 40s. calculate the distance and displacement coverd by him in 3 minutes. please explain this question
Answers
Distance in circular motion = Circumference of the circle
As we know, circumference of the circle is denoted by
2 \pi r2πr
Distance=
2 × \frac{22}{7}
7
22× 20
= 125.7 metre
This means he completed one round in 40 seconds. Thus, he takes 40 seconds to complete one round
Now for 3 minutes= 180 seconds
now taking the ratio,
\frac{125.7}{40} = \frac{x}{180}
40
125.7
=
180
x
Thus,
\frac{125.7*180}{40}=x
40
125.7∗180
=x
Thus
x=565.7
Thus he covered a distance of 565.7 metre in 3 minutes
for displacement let's divide the covered distance by circumference
=565.7/125.7
=450
this means he has completed 4 rounds and have completed 1/2 round extra, he is on a point parallel to his starting point
Displacement= 2×20
= 40m
ANS Distance covered in 3 minutes is 565.7 m and displacement is 40m