Advertisements
Advertisements
Question
The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times in a minute.
Advertisements
Solution
P = `(W.D)/"time"`
W.D in 1 heartbeat = 0.5 J
W.D in 72 heartbeats = 0.5 × 72 = 36 J
Time = 1 minute = 60s
∴ P = `(WD)/t = 36/60 = 6/10` = 0.6 W
As a result, the power consumed by the heart is 0.6 W.
APPEARS IN
RELATED QUESTIONS
A body is moving unidirectionally under the influence of a source of constant power. Its displacement in time t is proportional to ______.
Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s-1. Calculate the power exerted.
The S.I. unit of power is ..........
Two coolies A and B do some work in time 1 minute and 2 minute respectively. The power spent is
The expression of power P is
A pump raises water by spending 4×105J of energy in 10s. Find the power of the pump.
Name the physical quantity which is measured in calorie. How is it related to the S.I. unit of the quality?
Differentiate between watt and watt hour.
An electric heater of power 3 kW is used for 10 h. How much energy does it consume? Express your answer in
- kWh,
- joule.
If a 1200 W electric iron is used daily for 30 minutes, how much total electricity is consumed in the month of April?
Choose one or more correct alternatives.
Power is a measure of the ______.
- The rapidity with which work is done.
- Amount of energy required to perform the work.
- The slowness with which work is performed.
- Length of time.
What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop?.
Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine? (g = 10 m/s2)
Unit of power used in mechanical engineering is ______.
Name the quantity which is measured in kWh.
Name the quantity which is measured in eV.
At any instant of time t, the displacement of any particle is given by 2t – 1 (SI unit) under the influence of force of 5N. The value of instantaneous power is (in SI unit):
