4 ms·
It's somewhat counterintuitive how much energy can be in something moving so slowly. I say somewhat, because when you're up close it's much more obvious, but yo
by danpalmer 3y ago
It's somewhat counterintuitive how much energy can be in something moving so slowly. I say somewhat, because when you're up close it's much more obvious, but you're right that on a video it doesn't look like much.
- major505 3y agoForce = mass * acceleration, it might be slow but how much does a container shop weighs? 100, 200 thousand tons?
- hangonhn 3y agoThe same go for cars. I was hit by a car which was already slowing down but over ran the line and hit me. The car couldn't have been going more than 10 mph but it was enough force to fracture my knee (the fracture type is also colloquially known as a bumper fracture).
- throw0101b 3y ago> It's somewhat counterintuitive how much energy can be in something moving so slowly. Reminder: Kinetic Energy = ½mv^2 Squaring numbers can make them big in a hurry.
- dweymouth 3y agoBut in this case with slow speed, it's the massive (literally) amount of mass of the cargo ship that gives it an un-intuitively large amount of energy.
- trilbyglens 3y ago8kn isn't super slow
- lupire 3y agosqrt of 100K times weight of a car is 300 cars worth.
- eternauta3k 3y agoNitpick: squaring makes numbers greater than 1 bigger, and numbers smaller than 1 smaller. In this case we're squaring something with units, and we can't say the input is greater or smaller than the output, because they have different units. What we can say, is that v^2 curves upward: it grows faster with increasing v, and slower with decreasing v.
- deltarholamda 3y agoThis disconnect happens with boats quite a lot. For example, I can, by myself, pull a 45 foot grand banks trawler in shallow water. I know because I've done so. But at even very low speeds, I cannot stop it from hitting a pier. I have not tried to do this, but every harbor master has a bunch of stories about people trying to do so and getting a leg or an arm or something squished and pulverized. People who are not boat people rarely recognize these sorts of dangers, which is why so many get hurt on boats. "I can push us off the dock, so I can definitely keep us from hitting it." Nope, Sir Isaac Newton says you're wrong.
- paddy_m 3y agoTo anyone reading this who isn't an experienced boater: If you are invited onto someone else's boat, sit down and shut up during docking, don't talk to friends, let the captain concentrate. Don't help, if the captain wants you to do something, they will let you know. If you think you know better than the captain, and this advice is unknown to you, you don't know better. Being a good guest during docking shows experience and helps get an invite back.
- imoverclocked 3y agoThis advice also translates for general aviation during takeoff, landing and taxiing.
- CIPHERSTONE 3y agoThis is great advice. For myself, docking in windy situations can be nerve racking. The old adage is to only dock as fast as your willing to hit the pier, and for me this means slow as hell. I always let guests know exactly what I want them to do, and to your point, it's mainly to sit tight and let me focus.
- EB-Barrington 3y agoWind, current, tides, your own boat at risk as well as other people's boats alongside... docking can certainly get the heart pumping. (Liveaboard cruiser here)