Question

The left ventricle of the heart accelerates blood from rest toa velocity of +26 cm/s.

a) If the displacement of the blood during the acceleration is+2.0 cm, determine its acceleration (in cm/s^2).
b) How much time does blood take to reach its finalvelocity?

Answer 1

a) We can use the following kinematic equation to solve for acceleration:

v^2 = u^2 + 2as

where:

v = final velocity = +26 cm/s (taking upward as positive direction)

u = initial velocity = 0 cm/s (since the blood is starting from rest)

s = displacement = +2.0 cm (taking upward as positive direction)

Substituting the given values, we get:

(26)^2 = 2(2)(a)(2)

a = 169/4 cm/s^2

Therefore, the acceleration of the blood is 169/4 cm/s^2.

b) We can use the following kinematic equation to solve for time:

v = u + at

Substituting the values of v, u, and a from part (a), we get:

26 = 0 + (169/4)t

t = 104/169 s

Therefore, the blood takes 104/169 seconds to reach its final velocity of +26 cm/s.