As the Wikipedia entry above explains, velocity is the rate of change of the position of an object. What does that mean? Well, basically it means how far an object is going in a set amount of time. Velocity is measured in meters per second (m/s) and is also a vector quantity (meaning that it has a magnitude AND direction.) So, if a person is watching a car that is stationary (perpendicular from one side of the car) and the car moves in reverse, the velocity would generally be considered negative. However, this depends on the viewer's perspective. As an example, let's say that a car traveled 48 kilometers in 55 seconds. What is its velocity? First, let's convert 48 kilometers into meters. 48 km = 48,000 m Then, we would simply divide the distance the car traveled by the time it took to travel that far. 48,000m/55s = 872.727m/s (That's one fast car!)
Posted in Velocity
Tip: Usually the goldfish you win from carnivals are already in poor health and diseased. So, it's not wise to add a goldfish won from a carnival to a tank of healthy fish, for it can introduce illnesses to healthy and sometimes sensitive/susceptible fish. In my experience, it's best to keep goldfish you get from the carnival in a separate tank.
Posted in Goldfish
Physics explains how cats rotate their bodies to land on their paws every time they fall at an adequate distance from the ground. I apologize if this was already posted -- I scrolled down pretty far and hadn't seen it. I thought it was a very cool video. We can all learn a lot from this YouTube channel.
Posted in Cat
Studies show that teens need to be sleeping at least an hour more than the recommended time for adults (6-8 hours). Most teens need even more than that, putting them at needing 9+ hours of sleep every night. However, about 90 percent of teens aren't getting this amount of sleep in every night and about 10 percent of those teens said they get less than 6 hours of sleep. The reason for this can be linked to an overbooked schedule consisting of school, clubs and organizations, part-time jobs, etc. Also, teenagers' "natural clocks" (circadian rhythms) shift during this time of life. Therefore, melatonin is released until much later than when it would be in adults. This lack of melatonin at earlier hours leaves teens not feeling very sleepy until after 11 at night. So, it's not an act, parents! This leaves schools as the main cause of sleep deprivation among teens because of the early starting hours. The sleep deprivation of teens can lead to poor grades, traffic accidents, moodiness, and bad decision making.
Posted in Sleep