Forces applied to Fiat to explain damage to roof.
I have put this back in for Bunnie. If the groyne was flat with no vertical rocks. Fiat driven off groyne at 60 km/hr and assuming it would take 4 sec to hit ocean.
F = m x a F = 1150 x 15 =
4791 N
Bad news (for explaining damage to Fiat), is entry to the water would generate approx. half to one third the force to the fiat than rolling at a speed of 100km/hr, with
resulting minimal structural damage.
Good news is it's possible the driver could escape out the window.
If there were large waves breaking onto Fiat trapped on shore there would be forces on Fiat as well, not shore if large breaking waves on day.
It's never been clear in newspaper reports how the car was towed from the water, but I've asked some knowledgeable mates. They suggest WAPOL would have contracted a tow truck to pull car to shore, whether or not they though this was part of a crime scene. Possible rope or chain. Connect through back door windows and tow to shore.
Assume car is upside down as in reports. Forces on the roof of the car when towed in. Assume some water in car and weight of water needs to be taken into account.
I am happy for anyone to jump in here and this is only my understanding of how to calculate this. I will get other mates in towing to check.
- Force is the horizontal tension on the tow rope to get it moving and keep moving at a constant velocity.
T = ma
T = 1000 - 2000 x 1
T = 1000 - 2000N
To keep this horizontal tension constant is what towie try to achieve, otherwise too much tension on rope or chain and may snap.
If Fiat was travelling along the ocean bottom at a
constant velocity no vertical forces would be applied.
However there If there were bumpy small start/ stop accelerations (or vertical forces), IMO force would then be applied to the roof when towing in to shore. It would be like a car tapping on the breaks repeatedly and can increase rope or chain tension enough to snap.
How many times might this have happened? And what was the resulting
vertical force on the Fiat roof?
My est. on forces on car roof as it was being pulled in is ......( subject to expert checking, and will post later)
Example from you tube. A car being towed out of water on it roof up a concrete boat ramp before being turned. No major damage from being dragged up concrete boat ramp (Concrete also under water).