A 55 kg cheerleader uses an oil-filled hydraulic lift to hold four 110 kg football players at a height of 1.0 m. If her piston is 16 cm in diameter, what is the diameter of the football players’ piston?

Respuesta :

Answer:

[tex]D = 55.2 cm[/tex]

Explanation:

As we know that the total mass of the all four players is given as

[tex]M = 4\times 110[/tex]

[tex]M = 440 kg[/tex]

diameter of the piston of cheer leader is given as

[tex]d_1 = 16 cm[/tex]

are of cross-section is given as

[tex]A_1 = \pi r^2[/tex]

[tex]A_1 = \pi(0.08)^2 = 0.02 m^2[/tex]

mass of the cheer leader is given as

m = 55 kg

so the pressure due to cheer leader is given as

[tex]P_{in} = \frac{mg}{A_1}[/tex]

[tex]P_{in} = \frac{55 \times 9.81}{0.02}[/tex]

[tex]P_{in} = 26835 Pa[/tex]

Now on the other side pressure must be same

so we have

[tex]\frac{Mg}{A} + \rho gH = P_{in}[/tex]

[tex]\frac{440 \times 9.8}{A} + (900)(9.8)(1) = 26835[/tex]

[tex]A = 0.24 m^2[/tex]

[tex]\pi r^2 = 0.24[/tex]

[tex]r = 0.276 m[/tex]

so diameter on the other side is given as

[tex]D = 2 r[/tex]

[tex]D = 55.2 cm[/tex]