Question

Problem 3:
You start walking from a point on a circular field of radius 0.5 km and 1 hour later you
are at the same point.
a) What is your average speed for the whole journey?
b) What is your average velocity for the whole journey?​

Answer 1

Answer:

Step-by-step explanation:

Given,

Radius of the circular field = 0.5km

Time taken = 1hr

To Find :-

1) Average Speed

2) Average Velocity

Formula required :-

$Average\:speed=\dfrac{total\:distance}{time\:taken}$

$Average\:velocity=\dfrac{Total\:displacement}{time\:taken}$

Solution :-

1) Average Speed = ?

Total distance = Circumference of the circle = 2πr.

$= 2\times\dfrac{22}{7}\times0.5$

$=2\times\dfrac{22}{7}\times\dfrac{1}{2}$

$=\dfrac{22}{7}$

= 3.14km

Time taken = 1hr

$Average\:speed=\dfrac{3.14km}{1hr}\\\\= 3.14km/hr$

We know that :-

1km/hr = 5/18 m/s

$3.14km/hr=3.14\times\dfrac{5}{18}m/s$

$=\dfrac{22}{7}\times\dfrac{5}{18}m/s$

$=\dfrac{110}{126}m/s$

= 0.87 m/s

2) Average Velocity = ?

Total Displacement = 0

Reason :-

As we are started at the point and stopped at the same the displacement will be 0. Because displacement is the shortest path to travel.

Time taken = 1hr

$Average\:velocity=\dfrac{0}{1}$

= 0km/hr

Hence, the body not had velocity.