What is Momentum? Unit 8 Section 3

Momentum Momentum is a property of ALL moving objects Momentum is the product of the mass and velocity of an object. Momentum = mass x velocity ( P=M x V) Momentum is labeled as kg x m/s with a direction. i. For example- kg x m/s east

Picture This A bowling ball with a mass of 5kg is rolling towards the pins. A bowling ball with a mass of 8kg is rolling towards the pins in the next lane with the SAME VELOCITY. Which ball do you think will knock over more pins?

Picture This The ball with the greater mass (8kg) will knock over more pins. Why? Because it has more MOMENTUM!

What does it mean? e. The greater the mass, the greater the velocity, the greater the momentum. The smaller the mass, the less the velocity, the less the momentum. i. For example-A baby crawling has less momentum than a car driving at 20 mph.

Law of Conservation of Momentum Momentum can be transferred but not lost. When one moving object collides with another moving object, the motion of both objects change.

Newton’s Cradle Let’s take a look at Newton’s Cradle

Newton’s Cradle http://www.lhup.edu/~dsimanek/scenario/newton.htm Momentum from the sphere on the left is transferred through the row of spheres to the sphere on the right. http://www.lhup.edu/~dsimanek/scenario/newton.htm http://www.physics.org/article-interact.asp?id=32

Newton’s Cradle The sphere on the left will transfer its momentum through the row of spheres to the sphere on the right. The sphere on the right will move and transfer the momentum through the row back to the sphere on the left. Newton’s Cradle transferred the momentum, but none was lost.

Objects Sticking Together Sometimes objects stick together, like when a dog catches a Frisbee. When this happens, the mass of the combined objects is equal to the two masses added together. The objects will move in the direction of the object that had more momentum before they crashed together.

The mass of the Frisbee And the mass of the dog… …are added together to make a new mass. But the total momentum stays the same.

Objects Bouncing Off Each Other Sometimes objects bounce off of each other, like two bumper cars. When this happens, momentum is transferred from one object to another. But the total momentum remains the same.

The energy of this bumper car is… transferred to this bumper car But the total momentum stays the same!

Newton’s 3rd Law and Momentum Newton’s 3rd Law- For every action, there is an equal and opposite reaction. The first sphere hits the rest of the spheres (action force) and transfers the momentum through causing the last sphere to move (reaction force). What happens if we move 2 spheres (action force?)

Quickie Quiz Which of the following has the smallest amount of momentum? A loaded truck driven at highway speeds (60mph) A track athlete running a race A baby crawling on the floor A jet airplane being towed toward an airport