Answer:
[tex]\large \boxed{\text{1. Veins; 2. 600 W; 3. 45 N}}[/tex]
Explanation:
1. Arteries are the tubes responsible for the movement of blood from the heart to other parts of the body.
2. Power
(a) Work performed
w = mgh = 12 kg × 9.807 m·s⁻² × 15 m = 1800 J
(b) Power level
P = w/t = 1800 J/3 s = 600 W
3. Machine load
The formula for mechanical advantage (MA) is
[tex]MA = \dfrac{F_{o}}{ F_{e}}[/tex]
where
Fₒ = the force of the object
Fₑ = the force exerted to overcome that of the object
[tex]\begin{array}{rcl}MA & = &\dfrac{F_{o}}{ F_{e}}\\\\6 & = &\dfrac{F_{o}}{ \text{7.5 N}}\\\\F_{o} & = & \text{45 N}\\\end{array}\\\text{The machine can carry a maximum load of $\large \boxed{\textbf{45 N}}$}[/tex]