Question

Starting from the front door of your ranch house, you walk 55.0 mm due east to your windmill, turn around, and then slowly walk 40.0 mm west to a bench, where you sit and watch the sunrise. It takes you 25.0 ss to walk from your house to the windmill and then 37.0 ss to walk from the windmill to the bench.
Required:
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:

a) V = 0.24 m/s

b) v = 1.53 m/s

Explanation:

In this case, we are asked to find two values that are pretty similar and use the same units, however, there are differences between them.

The average velocity is often referred to a vector quantity, therefore, if time is a scalar magnitude, we need to find the vector quantity of distance. In this case, is the displacement, which is also referred as a vector.

So, to calculate the average velocity we need to determine first the displacement of the person. As the person heads east and then west, his total displacement (D) is:

D = 55 - 40 = 15 m

Now the total time would be the time taken to go to the windmill and then, to a bench:

t = 25 + 37 = 62 s

Finally, the average speed is:

V = D/t

V = 15 / 62

V = 0.24 m/s

The average speed is a scalar magnitude, so we use the covered distance by the person (d) and the total time:

d = 40 + 55 = 95 m

Then, the speed:

v = 95/62

v = 1.53 m/s

Hope this helps