Question

A. An object weighs 7.84 N when it is in air and 6.86 N when it is immersed in water. What is the specific gravity of the object?

b. How much pressure does it take for a pump to supply a drinking fountainwith 300 kPa, if the fountain is 30.0 m above the pump?

Answer 1

a

`W_s = 8`

b

`P = 594 000 \ Pa`

Step-by-step explanation:

Considering question a

From the question we are told that

The weight of the object in air is
`W_1 = 7.84 \ N`

The weight of the object in water is
`W_2 = 6.86\ N`

Generally the specific gravity of the object is mathematically represented as

`W_s = (W_1 )/(W_1 - W_2 )`

=>
`W_s = (7.84)/(7.84 -6.86 )`

=>
`W_s = 8`

Considering question b

From the question we are told that

The pressure required is
`P_r = 300 \ kPa = 300 *10^(3) \ Pa`

The height is
`h = 30.0 \ m`

Generally the pressure require to get the water to the given height is mathematically represented as

`P_h = \rho * g * h`

Here
`\rho` is the density of water with value
`\rho = 1000 \ kg / m^3`

So

`P_h = 1000 * 9.8 * 30`

=>
`P_h = 294000 \ Pa`

Generally the pressure require to pump the water to the given height at the require pressure is mathematically represented as

`P = P_h + P_r`

=>
`P = 294000 + 300*10^(3)`

=>
`P = 594 000 \ Pa`