e d g e - education for disability and gender equity


1 Work
2 Energy
3 Momentum
4 Center of Gravity


Newton's second law


stated that the acceleration of an object is directly proportional to the net force acting upon the object and inversely proportional to the mass of the object.

Momentum is a commonly used term in sports. When a sports announcer says that a team has the momentum they mean that the team is really on the move and is going to be hard to stop .

An object with momentum is going to be hard to stop. To stop such an object, it is necessary to apply a force against its motion for a given period of time. The more momentum an object has, the harder it is to stop. It requires a greater amount of force or a longer amount of time (or both) to bring an object with more momentum to a halt.

As the force acts upon the object for a given amount of time, the object's velocity is changed; and the object's momentum is changed. You have observed this a number of times if you have ridden a bus standing up. As the bus approaches a stop the brakes are used to force the bus to stop. The momentum you have standing up causes you to lurch forward even though the bus has stopped.

If the force acts opposite the object's motion, it slows the object down. If a force acts in the same direction as the object's motion, then the force speeds the object up. Either way, a force will change the velocity of an object. And if the velocity of the object is changed, then the momentum of the object is changed.

Center of mass of motion (demonstration)

(next section - CENTER of GRAVITY)

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