Answer:
The density of the rock is
(D) is correct option.
Explanation:
Given that,
Force = 20.0 N
Density = 1000 kg/m³
Suppose the scale new reads 12.5 N
We need to calculate the mass of rock
Using formula of force
Put the value into the formula
Scale reads 12.5 N after rock is totally submerged so mass of rock after submerged
We need to calculate the mass of rock
Using formula of force
Put the value into the formula
The scale reads 12.5 N = 1.25 kg so it is displacing 0.75 kg of water
We need to calculate the volume of rock using volume of water it displaces:
Using formula of volume
We need to calculate the density of the rock
Using formula of density
Put the value into the formula
Hence, The density of the rock is