Question
Blood is flowing 0.1 cm long and $2 \times 10^{-4}$ cm radius in the tube. The pressure difference at the ends of this tube is 20 mm mercury. Coefficient of viscosity of blood is $0.5 \times 10^3 kg m ^{-1} sec ^{-1}$. Find the rate of blood flow in the tube.

Answer

Given :
$l=0.1 cm=10^{-3} m,$
radius $r=2 \times 10^{-4} cm=2 \times 10^{-6} m$
Pressure difference $P =20 mm$ mercury
$\begin{aligned}& =20 \times 10^{-3} m \text { mercury } \\& =20 \times 10^{-3} \times\left(13.6 \times 10^3\right) \times 9.8 N / m^2 \\\eta & =0.5 \times 10^{-3} kg / m-sec\end{aligned}$
Hence, rate of blood flow in the tube
$\begin{array}{l}Q=\frac{\pi Pr^4}{8 \eta l} \\Q=\frac{3.14 \times\left(20 \times 10^{-3} \times 13.6 \times10^3 \times 9.8\right) \times\left(2 \times 10^{-6}\right)^4}{8 \times 0.5 \times 10^{-3} \times10^{-3}} \\Q=3.42 \times 10^{-15} m^3 / sec .\end{array}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Spring fitted doors close by themselves when released. You want to keep the door open for a long time, say for an hour. If you put a half kg stone in front of the open door, it does not help. The stone slides with the door and the door gets closed. However, if you sandwitch a 20g piece of wood in the small gap between the door and the floor, the door stays open. Explain why a much lighter piece of wood is able to keep the door open while the heavy stone fails.
Establish that work done is the product of the displacement and the force in the direction of displacement.
A simple pendulum performs S.H.M. about x = 0 with an amplitude a and time period T. What is the speed of the pendulum at $\text{x}=\frac{\text{A}}{2}?$
A transmission wire carries a current of 100A. What would be the magnetic field B at a point on the road if the wire is 8m above the road?
A 2 kg block is kept at rest on a flat surface. A horizontal force $F$ on the block is gradually increased. When the value of $F$ becomes 8 N the block starts moving. Once the motion starts, it starts moving at a uniform speed only with the help of 7N force. Find out :
(i) Static and dynamic friction coefficient.
(ii) When the value of $F$ is 5 N , then the static friction force acting on the block is.
(iii) When the value of $F$ is again 8 N the acceleration of moving block. ( $g = 9 . 8 ~ m / s ^2$ )
Find the maximum angular speed of the electron of a hydrogen atom in a stationary orbit.
A spring of mass 2.50kg is under a tension of 200N. The length of the stretched string is 20.0m. If a transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end?
Because of the friction between the water in oceans with the earth's surface, the rotational kinetic energy of the earth is continuously decreasing. If the earth's angular speed decreases by 0.0016rad/ day in 100 years, find the average torque of the friction on the earth. Radius of the earth is 6400km and its mass is $6.0 \times 10^{24}kg$.
A person of mass 50 kg stands on a weighing scale on a lift. If the lift is descending with a downward acceleration of $9 \mathrm{~m} \mathrm{~s}^{-2}$, what would be the reading of the weighing scale? $\left(\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}\right)$
Find the value of 60 W on a system having 100 g, 20 cm and 1 min as the fundamental units.