Question

A person is walking briskly in a straight line. The figure shows a graph of the person’s position as a function of time . What is the person’s average velocity between t = 6 s and t = 10 s?

Answer 1

We are given graph of position of a person

For finding velocity , we will have to find slope of the given curve

Since, we have to find average velocity between t=6s to t=10s

We can see that there are shape of curve between t=6 and t=10

t=6 to t=8:

There is a inclined line

we can select any two points on that line and find slope

(5,1) and (8,6)

now, we can find slope using formula

`m=(y_2-y_1)/(x_2-x_1)`

now, we can plug values

`m=(6-1)/(8-5)`

`m=(5)/(3)`

so, first velocity is

`v_1=(5)/(3) m/s`

t=8 to 10:

We can see that there is horizontal line

so, we can select any two points

(8,6) and (10,6)

now, we can find slope using formula

`m=(y_2-y_1)/(x_2-x_1)`

now, we can plug values

`m=(6-6)/(10-8)`

`m=0`

so,

`v_2=0m/s`

Average velocity between t=6 and t=10:

now, we can find average velocity

`v=(v_1+v_2)/(2)`

`v=((5)/(3)+0)/(2)`

`v=0.8`

so,

average velocity is 0.8m/s...........Answer