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

Question

The heart of a man pumps 5 litres of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be 13.6 × 103 kg/m3 and g = 10 m/s2 then the power (A) 3.0 (B) 1.50 (C) 1.70 (D) 2.35

Tardigrade Admin · Accepted Answer

Here,
Volume of blood pumped by man's heart,

V = 5

litres

= 5 \times 1 0^{- 3} m^{3} (∵ 1

litre

= 1 0^{- 3} m^{3})

Time in which this volume of blood pumps,

t = 1 min = 60 s

Pressure at which the blood pumps,

P = 150 mm

of

H g = 0.15 m

of

H g

= (0.15 m) (13.6 \times 1 0^{3} k g / m^{3}) (10 m / s^{2})

(∵ P = h ρ g)

= 20.4 \times 1 0^{3} N / m^{2}

∴

Power of the heart

= \frac{P V}{t}

= \frac{( 20.4 \times 1 0 ^{3} N / m ^{2} ) ( 5 \times 1 0 ^{- 3} m ^{3} )}{60 s} = 1.70 W

Q. The heart of a man pumps 5 litres of blood through the arteries per minute at a pressure of 150mm of mercury. If the density of mercury be 13.6×103 kg/m3 and g = 10m/s2 then the power

3.0

1.50

1.70

2.35

Q. The heart of a man pumps $5$ litres of blood through the arteries per minute at a pressure of $150 mm$ of mercury. If the density of mercury be $13.6 \times 1 0^{3}$ $k g / m^{3}$ and $g$ = $10 m / s^{2}$ then the power