A jogger jogs around a circular track with a diameter of 325 m in 12 minutes. What was the jogger's average speed in m/s?

Question

help with is question

Answer 1

All circles are similar (same shape) so linear dimensions are in proportion; the constant of proportionality is defined as pi so that C/D = pi for all circles.

 

avg speed =(circumference)/(time)

 

= ((325 m)(pi)/(12 minutes))(1 minute/60 seconds)

 

= 5*65(pi)/(12*5*12) m/s

 

= 65(pi)/144 m/s

 

≈ 1.41808001724539 m/s

 

 

Answer 2

Hi Whitney;

AS PER MICHAEL'S CORRECTION, I ADDED THE 3.14 INTO THE EQUATION.  SORRY!

diameter=325 m

perimeter=325(3.14) m

[(325 m)(3.14)/(12 minutes)][(1 minutes)/(60 seconds)]

The unit of minutes is in the denominator and numerator.  It cancels...

[(325 m)(3.14)/(12 minutes)][(1 minutes)/(60 seconds)]

[(325 m)(3.14)/(12)][(1)/(60 seconds)]

(325 m)(3.14)/(720 seconds)

(1021 m)/(720 seconds)