Question

Starting from the front door of your ranch house, you walk 50.0 m due east to your windmill, and then you turn around and slowly walk 40.0 m west to a bench where you sit and watch the sunrise. It takes you 28.0 s to walk from your house to the windmill and then 42.0 s to walk from the windmill to the bench.
(a) For the entire trip from your front door to the bench, what is your average velocity?
(b) For the entire trip from your front door to the bench, what is your average speed?

Answer 1

Answer:

Average velocity

$v=\frac{d}{t}\\ v=\frac{10m}{70s}\\v=.1428 \frac{m}{s}$

Average speed,

$S=\frac{D}{t}\\ S=\frac{90}{70}\\ S=1.29\frac{m}{s}$

Explanation:

(a)Average velocity

We have to find the average velocity. We know that velocity is defined as the rate of change of displacement with respect to time.

To find the average velocity we have to find the total displacement.

since displacement along east direction is 50m

and displacement along west=40m

so total displacement,

$d=50m-40m\\d=10m$

total time,

$t=28 s+42 s\\t=70 s$

therefore, average velocity

$v=\frac{d}{t}\\ v=\frac{10m}{70s}\\v=.1428 \frac{m}{s}$

(b)Average Speed:

Average speed is defined as the ratio of total distance to the total time

it means

Average speed= total distance/total time

here total distance,

$D= 50m+40m\\D=90m$

and total time,

$t= 28s+40s\\t=70s$

therefore,

Average speed,

$S=\frac{D}{t}\\ S=\frac{90}{70}\\ S=1.29\frac{m}{s}$