My PBL Project

Introduction:

• Why does a raw egg break when it is thrown against the wall but does not break when it is thrown with the same velocity into a hanging sheet? What prevents the egg from breaking? This all pertains to Momentum and Impulse. Momentum is mass times velocity. Impulse is force times time. The more momentum an object has, the harder it's going to be for the object to stop. The Impulse-Momentum Theorem given by the physicsclassroom.com stated: "In a collision, an object experiences a force for a specific amount of time that results in a change in momentum. The result of the force acting for the given amount of time is that the object's mass either speeds up or slows down (or changes direction). The impulse experienced by the object equals the change in momentum of the object."

Materials:

• Eggs

• A Pillow

• A Hard Surface

Procedure:

1. First, grab an egg.

2. Then, throw it at the pillow.

3. See what happens.

4. Then, grab the egg and throw it at a hard surface.

5. Record what happens.

6. Afterwards, take your results and explain what happened.

Scientific Principle:

• When the egg hits the brick wall, the egg comes to rest in a very short time interval. The force the brick exerts on the egg due to the collision is large. When the egg hits the sheet, the egg goes through the same change in momentum, but over a much longer time interval. So, the force required to accelerate the egg to rest is much smaller. By applying a small force to the egg over a longer time interval, the sheet causes the same change in the eggs momentum as the brick wall, which applies a large force over a short time interval. Because the force is smaller in the sheet, the egg can withstand it without breaking.

• Momentum: a quantity defined as the product of the mass and velocity of an object. Momentum = Mass X Velocity

• Impulse: the product of the force and time over which the force acts on an object. Impulse = Force X Time Interval, which then equals change in momentum.