Egg Throwing (My PBL Project)

Introduction

In this project, I will throw eggs at a bed sheet and a wall(door) to see how the egg is impacted when they come into contact.

Driving Question- How are momentum and impulse involved in the collision between the egg and the sheet/the wall?

Hypothesis- If the eggs are thrown at the same velocity and are the same mass, the egg thrown at the sheet will experience a smaller force but for a longer time while the egg thrown at the wall (door) will experience a bigger force but for a shorter time.

Materials

• • 1 wall (door)

  • 1 sheet

  • 2 eggs

Procedure

• 1. Obtain a wall or any flat hard surface that can be stood up

  2. Throw an egg at it. Record observations.

  3. Obtain a sheet and hang it on a clothesline with two objects at the bottom of the hanging part to keep it from flying in the wind, or have two people each hold two sides so that the sheet makes a J shape.

  4. Throw an egg at it. Record observations

Safety

The eggs upon breaking will splatter. Therefore, it is advised for the experiment to be done outside, protect the area with newspaper or plastic, or be prepared to clean up eggs from the floor.

Pictures and/or Action Video(s)

Scientific Principle / Essential Understanding

An object with higher momentum is harder to stop. In order to stop such an object, you would need to apply a force against its motion for a given period of time. The more momentum this object has the more force and/or time you would need to stop it. When you apply force in the opposite direction of the momentum you change the object's momentum.

Impulse and momentum both come from the Second Law of Motion:

Fnet = m • a

Acceleration (a) is simply ∆v / t.

Therefore:

F = m • ∆v / t

So if you multiply t on both sides you get:

F • t = m • ∆v

This is where impulse and momentum come into place. In physics, Force • Time is known as Impulse and since m • v is momentum then m • ∆v is change in momentum. Therefore, Impulse = change in momentum.

How does this apply to egg throwing?

The egg thrown to the wall and the egg thrown to the sheet both experienced the same change in momentum. The difference was in how this change was experienced. The egg thrown at the wall had a change in momentum with a greater force over a shorter amount of time (1 second). By contrast, the egg thrown at the sheet had a change in momentum with a smaller force over a longer period of time (3 seconds). This was evident it how the egg was affected. Because a greater force was exerted by the wall on the egg than by the sheet on the egg, the egg thrown to the sheet did not break upon impact.

Real Life Connection / Further Applications

During our daily commutes, we encounter one or more car crashes. Impulse and momentum are very involved in these accidents. A car's momentum is changed when the car crashes. This changed momentum equals the impulse. Because car crashes happen so often, engineers create cars that have a high possibility of saving someone's life.

Imagine this: a car is going at 50 miles an hour and crashes into a concrete wall. The front car a the car is made out of really hard material and stops upon impact, hurting only one foot of the hood and fender. This would mean that the car stopped with more force over a shorter period of time. This force has to exerted upon something according to the conservation of energy. Let's remember the experiment in which the egg was thrown towards the wall. What happened to it? It broke. That broken egg would represent an extremely injured driver and/or passenger or in a worse case scenario dead.

(Click on image to see GIF)

Now imagine this: a car is going at 50 miles and crashes into a concrete wall. The front of this car is made out of more malleable material. Therefore, it hits the wall and scrunches up 3 feet of the hood and fender. The car stops with less force over a longer period of time. Let's remember the egg thrown at the sheet. What happened to it? Nothing. The unhurt egg would represent a safe and sound driver and/or passenger. They would survive the crash.

(Click on image to see GIF)

Investigation Questions

1. What is momentum?

Momentum is the quantity of motion of a moving body (in this case an egg or a car). It is calculated using mass • velocity.

2. What is impulse?

Impulse is a force applied to an object that produces an equivalent vector change in its linear momentum (basically a force applied to change its momentum). In physics, Impulse is calculated using Force • Time.

3. How are impulse and momentum related?

When the Second Law of Motion (Fnet= m • a) is rearranged we are able to obtain F • t = m • ∆v. If m • ∆v is the change in momentum and F • t Impulse, then Impulse is equal to the change in Momentum. Thus, in order to change the momentum of an object, impulse must be applied in the opposite direction.

4. How does egg throwing apply in the real world?

This egg throwing demonstration helps explain the physics in car crashes. The front part of the car needs to be malleable so that less force is exerted on the driver over a longer period of time just as the egg thrown at the sheet experienced less force over a 3 second period in comparison to the egg thrown at the wall which experienced a greater force for a 1 second period of time.