Calculation results of Moment of Inertia (in class example)

I=0.1052+7.378*0.3²+0.0504+2.901*0.45²+0.0038+0.883*0.53²=1.6589 kgm²

1) Yes r=891.947 kg/m³ W=769.1N

2) N=5

3) 0.0613m3

4) Increasing body volume caused decreasing body density.

5) Deep breath (see Question 4 for further explanation)

6) Skinny person, because the density of bone is higher than water.

7) Greater salt content increases the fluid density. The higher the fluid density, the more likely the body will float.

8) Initial position: Not on the same vertical line.

End position: both centres lie on one vertical line.

9) The centre of gravity moved towards thorax.

Float centre was relatively unchanged.

So both centres lie on one vertical line.

10) Reduce the turbulence range behind the helmets, so the drag force is reduced.

11) Slower because the lift force generated by backspin is upward.