At the beginning of systole, when ventricular pressure exceeds atrial pressure, the AV valves close. However, initially the semilunar valves also remain closed since ventricular pressure is still not sufficiently strong enough to force them open (consequently at this point in the cardiac cycle there is no blood flow into or out of the ventricles). This phase is known as . A) isovolumetric relaxation (phase 4)
B) isovolumetric contraction (phase 2)
C) ventricular ejection (phase 3)
D) ventricular filling (phase 1)

i sometimes feel that way too. i feel that i should hurt someone because they hurt me, but i wouldnt do it. that would make things so much worse i have so much experience with this stuff

explanation:

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr