Answer:
3.679 × 
Explanation:
Let's assume that average lifespan for normal human being is 70 years.
In 70 years there are 365 days in each year.
70 years = 70 × 365 days
In one day there are 24 hours.
70 years = 70 × 365 × 24 hours
In one hour there are 60 minutes.
70 years = 70 × 365 × 24 × 60 minutes
we estimate an average respiration rate of about 10 breaths per minute. ... (Given)
Thus, for 70 years number of breath are,
n = 70 × 365 × 24 × 60 × 10
n = 3.679 ×
Hence, estimate number of breath over a period of life is 3.679 × .
Imagine a ball is moving on the following horizontal line.
. . . . . . . . . . . . . . . . . . . O. . . . . . . . . . . . . . . . . .
Take right as positive. O is the starting point of the ball. Denote the ball by o.
. . . . . . . . . . . . . . . . . . . O. . . . . . . ... . . o . . . . . .
Assume the ball is moving to the right. It has positive displacement since it is on the right of O, and positive velocity since its positive displacement is increasing.
.ñ
. . . . . . . . . . . . . . . . . . . O. . . . o . . . . . . . . . . . . .
Now the ball is returning to O. It still has positive displacement since its current position is still on the right of O. However, its velocity is negative since its positive displacement is decreasing and the direction of the velocity vector points left, which is the negative side.
By now you should be able to come up with a scenario where the ball has negative displacement and positive velocity.
You can observe the same phenomenon in daily life. Say, as a stretched spring bounces to its starting position, if we let the returning direction be positive, the string has negative displacement since it is on the negative direction, but has positive velocity. Bungee jump can also used to illustrate the phenomenon.
