Question

A glass of water sits on a scale. The scale reads 4.78 N. A steel bolt weighs 2.07 N. The density of steel is 7.86 g/cm3. We tie the bolt to a string and lower the bolt into the glass of water so that the bolt is fully submerged in the water but is not touching the bottom or side of the glass.

Answer 1

The weight of water weight is 5.043 N.

Step-by-step explanation:

Given that,

Force = 4.78 N

Weight of steel bolt = 2.07 N

Density of steel = 7.86 g/cm³

Suppose determine how much does the glass of water weight.

We need to calculate the volume of bolt

Using formula of density

`\rho_(b)=(m)/(V)`

`V=(m)/(\rho_(b))`

Put the value into the formula

`V=(2.07)/(9.8*7860)`

`V=2.6873*10^(-5)\ m^3`

We need to calculate the force on bolt

Using buoyant force

`F=\rho gV`

Put the value into the formula

`F=1000*9.8*2.6873*10^(-5)`

`F=0.263\ N`

We need to calculate the new weight of glass of water

Using formula for weight of glass of water

`W'_(w)=W_(w)+F_(b)`

Put the value into the formula

`W=4.78+0.263`

`W=5.043\ N`

Hence, The weight of water weight is 5.043 N.