+91-8076753736[email protected]
logo
logo
-->

Work, Energy And Power

Question
CBSEENPH11020649
Wired Faculty App

The heart of a man pumps 5 L of blood through  the arteries per minute at a pressure of 150 mm of mercury . If the density of mercury be 13.6 x 103 kg/ m3 and g = 10 m/s2, then the power of heart in watt is  

  • 1.70

  • 2.35

  • 3.0

  • 1.50

Solution

A.

1.70

 Given, pressure = 150 mm of Hg
Pumping rate of heart of a man
 = fraction numerator d straight V over denominator d straight t end fraction space equals space fraction numerator 5 space straight x space 10 to the power of negative 3 end exponent over denominator 60 end fraction space straight m cubed divided by straight s Power space of space heart space equals space straight P space. dV over dt space equals space ρgh space. space dV over dt space left square bracket space straight p equals space ρgh right square bracket rightwards double arrow space fraction numerator left parenthesis 13.6 space straight x space 10 cubed space kg divided by straight m cubed right parenthesis left parenthesis 10 right parenthesis space straight x 0.15 space straight x space 5 space straight x space 10 to the power of negative 3 end exponent space over denominator 60 end fraction space equals space 1.70 space straight W

Some More Questions From Work, Energy and Power Chapter

Does the body at rest possess energy?

By eating two apples, a person starts pushing the wall of room. If food value of apple is 100 calories per apple, how much work he will do in pushing the wall in one hour?

A man is rowing upstream and is at rest w.r.t. shore. Is he doing work w.r.t. shore?

Is frictional force conservative?

What is the work done by gravitational force in taking the mass m with constant velocity through height h?

A mass is tied with a string and whirled in horizontal circle. What is the work done by tension force?

Does the work done by force depend upon the velocity at that instant?

What is the work done by man against gravity when he is carrying a load on his head and walking on the horizontal road?

Are all central forces conservative?

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation