Question

Blood is accelerated from rest to 30.0 cm/s in a distance of 1.80 cm by the left ventricle of the heart. How long does the acceleration take?

Answer 1

Acceleration will take for 0.12 seconds.

Step-by-step explanation:

Given:

Initial velocity of the blood,
`v_i` = 0 m/s

Final velocity of the blood,
`v_f` = 30 cm/s = 0.3 m/s

Distance to be considered,
`x` = 1.80 cm = 0.018 m

We have to find the time taken to covered the said distance.

Let the time taken be "t" seconds.

Equation of motion:

⇒
`v_f=v_i+at` ...equation (i)

⇒
`x=v_it+(at^2)/(2)` ...equation (ii)

Now,

Using equation (i) we can say that:

⇒
`v_f=v_i+at`

⇒
`0.3=0+at`

⇒
`0.3=at` ...equation (iii)

Plugging x = 0.018 m in equation (ii).

⇒
`x=v_it+(at^2)/(2)`

⇒
`0.018=0+((at)(t))/(2)` ...breaking at^2 as (at)(t)

⇒
`0.018=((at)(t))/(2)`

⇒
`0.018=(0.3* (t))/(2)` ...plugging at=0.3 from equation (iii)

⇒
`0.018* 2=(0.3* (t))/(2)* 2`

⇒
`0.036=0.3* (t)`

⇒
`(0.036)/(0.3) =(0.3* t)/(0.3)`

⇒
`0.12\ s = t`

The acceleration will take for 0.12 seconds.