Best Results From Yahoo Answers Encyclopedia

From Encyclopedia


acceleration change in the velocity of a body with respect to time. Since velocity is a vector quantity, involving both magnitude and direction, acceleration is also a vector. In order to produce an acceleration, a force must be applied to the body. The magnitude of the force F must be directly proportional to both the mass of the body m and the desired acceleration a, according to Newton's second law of motion, F = ma. The exact nature of the acceleration produced depends on the relative directions of the original velocity and the force. A force acting in the same direction as the velocity changes only the speed of the body. An appropriate force acting always at right angles to the velocity changes the direction of the velocity but not the speed. An example of such an accelerating force is the gravitational force exerted by a planet on a satellite moving in a circular orbit. A force may also act in the opposite direction from the original velocity. In this case the speed of the body is decreased. Such an acceleration is often referred to as a deceleration. If the acceleration is constant, as for a body falling near the earth, the following formulas may be used to compute the acceleration a of a body from knowledge of the elapsed time t, the distance s through which the body moves in that time, the initial velocity vi , and the final velocity vf :

From Omilili

Newton's Second Law Problem?

Force = mass x acceleration F = m*a Acceleration is rate of change of velocity Acceleration Ft = MV this is the same as F = MA because V/T is acceleration. so by plugging in: 3100N x 6.5s Force = mass x acceleration F = m*a Acceleration is rate of change of velocity Acceleration a = Velocity v / Time t Therefore...

Accelerated c++ example problem - C++

Hello guys, sorry if it's wrong topic name but in accelerated c++ book and in chapter 2 exactly ; This is where you're calculating the row and column sizes The first line --> rows = pad * 2 + 3, comes out in the code the placement of the greetings text is not centred. cols on the other hand is a calculated

From Yahoo Answers

Question:Can anyone give me good creative examples of Newton's 3 laws. I need them for my project. For the third law, I don't want to hear the rocket example again. Please, thanks

Answers:Inertia: If you shoot a bullet, it keeps moving until gravity causes it to sink a hole in the ground or until it gets stopped by some poor soul. F=ma: Say the engine of a car and that of a motorcycle are equally powerful. If both provide the same force, the motorcycle will speed up at a faster rate than the car because the motorcycle is less massive and will therefore have a greater acceleration. Action-Reaction: You punch a wall. The wall punches you back. The wall doesn't move because it is much more massive than you are. Your punch recoils.

Question:I just need 1 for every law.

Answers:1st Law: Objects do not accelerate (speed up, slow down, change direction) unless an unbalanced external force is applied. Three examples (pick your favorite): A) The planets would all fly off in a straight line if the Sun's gravity weren't constantly pulling them into an elliptical orbit. B) That couch isn't going to move itself! A motionless couch will remain motionless unless you apply enough force to overcome the static friction holding it in place. C) In the absence of gravity, a spaceship would continue traveling in a straight line forever at a constant speed unless the ship's pilot turned the ship around and fired his thrusters in the opposite direction. The only way to change an object's speed or direction is to apply an unbalanced force. 2nd Law: The magnitude of an object's acceleration is direction proportional to the amount of force applied and inversely proportional to the object's inertia (mass). Two examples here: A) You're pushing a kid on a swing. Give him a weak push and he barely moves, but if you give him a STRONG push he's going for quite a ride. B) Say you apply equal force to two boxes. One has a mass of 10 kg and the other has a mass of 1000 kg. The 10-kg box will accelerate much faster than the 1000-kg box due to its lower mass (and decreased resistance to acceleration). 3rd Law: Forces come in pairs; for every force there is an equal force applied in the opposite direction (or, it is impossible to push without being pushed) Two examples here: A) You fire a rifle and feel the recoil. The explosion inside the gun pushed the bullet forward, but it also pushed the gun back with equal force. Because the bullet was tiny, its acceleration was huge, but the much bigger rifle experienced a much smaller acceleration (Newton's 2nd law). B) We can detect distant planets because they cause their parent star to wobble. The star attracts the planet through gravity, but the planet also attracts the star. As the planet swings around the star in a big orbit, the star swings around in a tiny circle. I hope this helps. Good luck!

Question:One is defined as = / t The other as: a = v^2/r Whats the difference in a more conceptual theoretical form?

Answers:Angular Acceleration: If you have the turntable going at the 33 1/3 RPM speed and switch it to 45 RPM, the increase in rotation speed is due to Angular Acceleration. It acts on all atoms making up the record and the direction of the vector is along the axis of rotation. The polarity is according to the "Right Hand Rule" - holding your right hand over the turntable with your fingers following the increasing angular velocity, your thumb points in the direction of the vector. I don't remember if turntables rotate Clockwise (CW) or Counter-Clockwise (CCW). Let's say it's CW, then the acceleration vector points down into the plane of the record. If you change the speed from 45 to 33 1/3, the acceleration vector would point up because it's a deceleration. Centripetal Acceleration: If you put a coin at the outer edge of the record, and if it doesn't fly off, it's because there is enough friction to hold it. Assume the turntable is at a constant speed setting. The linear velocity vector of the coin has a constant magnitude, but its direction is continually changing. At all points, the velocity vector is tangential to the circular path it follows. In order to change a velocity vector, either in magnitude or direction, acceleration must be applied. In the case of our coin, centripetal acceleration is what it is called - it means seeking a center. The value of this acceleration is given by (v^2)/r where v is the linear velocity of the coin and r is its distance from the center. Friction is providing the force for the centripetal acceleration in the case of our coin. Satellites orbiting the Earth also experience centripetal acceleration, provided by gravity. The term Centripetal Force is also used in these discussions. It's whatever force is providing the centripetal acceleration. In the case of our coin, the force of friction is the Centripetal Force. Circular Acceleration: I wasn't familiar with this term. Go to the site http://imagine.gsfc.nasa.gov/YBA/cyg-X1-mass/more-circular.html and note the comments to the right of the animation. It seems that this term is synonymous to centripetal acceleration. Centripetal Force, OK what's Centrifugal Force?: Newton's 3rd law says that a reaction force must counter the force for the centripetal acceleration. The centrifugal force is often mistakenly thought to cause a body to fly out of its circular path when it is released; but, it is the removal of the centripetal force that allows the body to travel in a straight line as required by Newton's first law. Centrifugal force is a virtual, or phantom, force. It is not really a force. Think of a bag of groceries sitting on the seat of a car when the driver slams on the brakes. Does some force make the groceries accelerate forward? No, the groceries just continued to move forward. That's another example of a virtual force. Now think of the groves in the record where the coin is sitting. The groves experience a force trying to bend them outward. This is the Centrifugal Force. So if the friction breaks down at 78 RPM and the coin flies off, it would fly in a direction tangential to the curve of the record where it broke loose (until gravity got it to accelerate towards the floor). Not directly outward. When the Centripetal force (friction) breaks down, the Centrifugal would also, and momentum and gravity would be the only things acting on the coin.

From Youtube


A worked example of a Newton 2nd Law Problem by James Dann for CK12.org CC by SA

Physics example 1D Kinematics constant acceleration

Example Physics problem: car accelerates between Vi and Vf over a given time, how far does it go?

Newton's Laws Problems (part 1)

Examples of exercises using Newton's laws.

Velocity and Acceleration Vectors Example 4

www.integralcalc.com. Finding velocity and acceleration vectors. College calculus tutor offers free calculus help and sample problems. Please visit my website for more videos, or to contact me for help with calculus.

Warning: mysql_close(): supplied argument is not a valid MySQL-Link resource in /edu-source/cbsenext/cfw/index.php on line 550