The difference in weight is due to the
displacement of water (the buoyancy of water is acting on the athlete thus
giving her smaller weight).<span>
The amount of weight displaced or the amount of buoyant force
is: </span>
Fb = 690 N - 48 N
Fb = 642 N
From newtons law, F = m*g. Using this formula, we
can calculate for the mass of water displaced:
m of water displaced = 642N / 9.8m/s^2
m of water displaced = 65.5 kg
Assuming a water density of 1 kg/L, and using the
formula volume = mass/density:
V of water displaced = 65.5kg / 1kg/L = 65.5 L
The volume of water displaced is equal to the
volume of athlete. Therefore:
V of athlete = 65.5 L
The mass of athlete can also be calculated using,
F = m*g
m of athlete = 690 N/ 9.8m/s^2
m of athlete = 70.41 kg
Knowing the volume and mass of athlete, her
average density is therefore:
average density = 70.41 kg / 65.5 L
<span>average density = 1.07 kg/L = 1.07 g/mL</span>
