Unit 7: Continued

Today, we continued learning about Momentum. We saw real life applications of what we were learning throughout the day by visiting a car crash scene (elastic and inelastic collisions), catching water balloons in towels (P=mv), and doing yet another air track lab, which showed us more about momentum and inelastic collisions.

Inelastic collisions happen when two objects colliding stick together on impact. An example of this could be the Air track lab, where we stuck a piece of clay onto one of the carts and pushed a cart into the cart with clay, causing a collision and a resulting two cart object.

Elastic collisions happen when two objects colliding bounce off one another, like a golf ball and a tennis ball. Like the demonstration in class with the rubber ball and the golf ball, when you drop a golf ball on a tennis ball, they change velocities depending on their mass. Since the golf ball is smaller, the velocity from the tennis ball will transfer to the gold ball.

Our lab(?) with water balloons showed us more about longer time of impact, along with the car crash scene. On one hand, throwing a water balloon up and catching it with a soft surface like a towel extends the time of impact with spreads out the force of the water balloon. This makes it easier not to break versus having the balloon hit the concrete. Speaking of, when a car hits a concrete wall, it will crush, like we saw today. Because the concrete/rock wall is hard, there is nothing to cushion the fall to spread out the force. If the car ran into a super huge stack of towels, it wouldn't have been as damaged because there is a longer impact time.