# Homework Help: Find the new blood pressure

1. Oct 19, 2004

### HeatherMrkr

I am not great at physics and am in an intro class for health sciences.....here is my problem.
A person with a blood pressure of 160/100 takes a drug that causes a 6% increase in the radius of the arterioles. Find the new blood pressure assuming no change in heart output or stroke volume.
I tried 160/.06 and 100/.06 don't I have to do something with r^4? If I do that, I still come up with the wrong answers.
thanks!
Heather

Last edited: Oct 19, 2004
2. Oct 20, 2004

### kenhcm

Pressure is defined by the force per unit area. The force is the same since no change in heart output has been assumed. The area concerned here is the area of the asterioles and is proportional to r^2. Since the radius increases, the area increases too and hence the pressure drops. The new pressures will be 160/(1.06)^2 and 100/(1.06)^2.

I am not very sure whether I answer your question correctly. Sorry if I did it wrongly.

Best regards,
Kenneth

3. Oct 20, 2004

thanks