Joe13
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We all know that gravity is the reason for things falling but nobody really knows why. We do know how to find and calculate gravity which helps us understand it better. Newtons law of universal gravitation helps to understand a little more of how gravity works. It states that any two things with mass have a gravitational force between them. The more mass and the closer they are means the more gravity they have. So all of us are pulling on everything with mass all the time but our masses are so small compared to the mass of the earth that it does not have an effect. The Law of Universal Gravitation does not just apply to objects on earth but the entire universe thats why its called universal. Using this law we can discover the gravitational force on any planet that we know the mass of before we even go there.
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We can explain the physics of running in a circle using the laws of centripetal acceleration and centripetal force. When we move in a circle we are always accelerating even if we move at constant acceleration. This happens because acceleration is the rate of change of velocity and velocity is a vector which means it has maginitude and a direction. So even if you do not change your speed when moving in a circle you are still accelerating because you change your direction. The word centripetal means "center-seeking" So the direction of the acceleration is always pointing toward the center of the circle.
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There is a lot of physics when two cars crash into each other. The crash invloves all of newtons three laws. It also involves momentum and friction. There are two diffrent types of collisions they are ellastic and inelastic. Ellastic is when the two objects bounce off of each other and inelastic is when they dont. In a car crash it is neither completley ellastic or completley inelastic but a combination of both. If a car brakes before the collision then you can use friction to find how much force it had on impact. You can also use momentum to see which car should have done more dammage. The law of momentum states that momentum is connserved in a collision.
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Straws are everywhere and everyone sees them and knows what they are and everyone uses them. A lot of people dont know how a straw actually works. You may think that you are actually sucking hard enough to pull the liquid up but thats not actually what happens. Air pressure is pressing down through the straw and holding the liquid in the cup. but when you suck the air out of the straw you change the air pressure making it lower inside the straw than outside of the straw and the liquid is drawn upward. when you suck the air out you create a vaccume were there is no air and the liquid is free to move upward just as if it were still in the cup.
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At some time in everybodys life they will probably hammer a nail into something but what you may never think about is how much physics there is when you hammer a nail. When you strike a nail you apply a force and even when you hit it hard the nail applys the same force back on the hammer as the hammer did to the nail. this may be weird to think about. In order to transfer the most energy from the hammer to the nail you must hit it right on the head or some of the energy may be lost. also depending on how dense the wood is there may be more or less friction acting on the nail when it is driven into the wood. if it is more dense then it will have more friction and you will have to apply a larger force to transfer the most energy and drive the nail further.
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Every time you throw a base ball you are using physics. When the ball is launched at an angle it is given a horizontal and vertical velocity. The force of gravity pulls on it at -9.81m/s^2 the entire time it goes up and pulls on it a positive 9.81m/s^2 the entire time it comes down. This force only works in the vertical direction the acceleration in the horizontal direction is zero. If the ball is timed from the time it left your hand to the time it hit the ground you can find the angle it was launched at which was hopefully 45 degrees because that gives it the maximum distance. and you can also find how high it flew. there is a lot of physics in baseball