Answer:
The work efficiency formula is efficiency = output / input, and you can multiply the result by 100 to get work efficiency as a percentage. This is used across different methods of measuring energy and work, whether it's energy production or machine efficiency.
Explanation:
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Answer:
140 J
Explanation:
From the the question, the mass of the man =70.0 kg and the speed at which the man is walking =2.0 m/s.

where K.E = the kinetic energy, m=mass and v= speed.
By substitution,



Hence the kinetic energy of the man is 140J
When the velocity increases, then the acceleration will be positive and when the velocity decrease then the acceleration will be negative.
During the first hour, the velocity was 70 mph and during the seconds hour the velocity was 60 mph. Hence, the velocity decrease in the seconds hour. So, the acceleration will be negative during the second hour.
Now, during the third hour the velocity increases as it is 80 mph. Hence, the acceleration will be positive during the third hour.
Can you reword the sentence?
We know that the Pythagorean theorem applies only to right triangles, therefore the original vectors must be parallel to the legs of a right triangle.
In other words, they must be orthogonal (i.e. perpendicular to each other) in order that the Pythagorean theorem applies.