Question

Blood squirts from a syringe at a speed of 5 m/s. the diameter of the needle opening is .002 centimeters. what is the pressure difference between the blood inside the syringe and the air outside? (assuming the syringe is horizontal and that the velocity inside is zero)

Answer 1

I would use Bernoulli's equation:

With the same level (so `y_1=y_2`) and `v_1=0`, giving:

and
`Deltap=v_2^2*rho/2` where `rho=10^3 (kg)/m^3` is the density of water (considering it as blood).
Giving: `Deltap=12500 Pa`

Check my maths!