A jogger runs in a straight line with an average velocity of 4.7 m/s for 3.3 min, and then with an average velocity of 5.8 m/s for 4.4 min. What is her average velocity?

1 Answer
Apr 13, 2017

Answer:

#5.32857142857/sec) = color(red)("average velocity")#

Explanation:

Take #v_1# as 4.7m/s
#t_1# = 3.3m

Use this equation to calculate the distance

#v_1xx t_1 = d/cancel(t)*cancel(t_1)#

#v_1 xx t_1 = d#

Where dis distance
t is time
v is velocity

Plug in the variables
3.3min must be converted to secs

#3.3cancel(min) xx (60sec)/cancel(min) = 198sec#

#(4.7m)/cancel(sec) xx 198cancel(sec) = 930.6m = d_1#

Do the same for #v_2# that is the another velocity

= #(5.8m)/sec xx (4.4min xx (60sec)/(1cancel(min)))#

= #(5.8m)/cancel(sec) xx 264cancel(sec) =1531.2m = d_2#

#(Deltad)/(Deltat) = "average velocity"#

#Deltad = d_1 + d_2 = 930.6m + 1531.2m = 2461.8#

#Deltat = t_1 + t_2 = 198sec + 264sec= 462sec#

#(Deltad)/(Deltat) = (2461.8m)/(462sec) = 5.32857142857/sec#

#5.32857142857/sec) = color(red)("average velocity")#