# What Happens When Objects Collide – Collisions in Physics

Teach collisions in physics to show kids what happens when objects collide. In this set of physical science activities, students explore collisions using miniature pool tables.

## Ms. Sneed’s Class Builds Miniature Pool Tables

Our favorite fourth grade teacher, Ms. Sneed, stared at the science standard:

Ask questions and make predictions about the changes in energy that occur when objects collide.

“Remember what we did last year?” she asked her teaching partner.

“Yep. First we gave each science group two meter sticks and three marbles. Then we let them explore,” said Mr. Frank.

“Fun. But not necessarily meaningful,” Ms. Sneed responded. “Let’s look for something with a little more structure.”

As usual, Mr. Frank pulled out his laptop and began searching. “Hey, what about these pool table collisions activities?” He shifted in his seat so Ms. Sneed could look over his shoulder.

“Looks like fun. What would we need?” Ms. Sneed asked.

### Building a Miniature Pool Table – Where Objects Collide

“Felt, skewers, and marbles,” Mr. Frank responded. “However, its says here that we can get all of this stuff at the dollar store.”

“Because the materials are so inexpensive, we could let each child build their own!” Ms. Sneed exclaimed. “How do they build the pool table?”

“First, we print and copy the pool table templates. After we distribute them, kids fold up the edges. That way, the marble won’t roll off. Then they cut the felt, and that’s pretty much it.”

### Creating a Bumper

“This pool table has no rigid sides. Therefore, kids also build a bumper. For this, they stretch the top part of a balloon over a section of a toilet paper tube.”

## Exploring What Happens When Objects Collide

“I see that the bumper is used in the first activity,” said Ms. Sneed. “At first, kids shoot their marbles straight at the bumper. Then they try angle shots.”

“So simple. Yet really appropriate for our fourth graders. The initial activities let them practice shooting. In addition, they conceptualize equal and opposite reactions. Then they build on that by bouncing the marble at an angle. I like it.”

“In the second set of activities,” Ms. Sneed continued, “kids explore whether the marble moves in the same or different direction as the cue stick and the marble that hits it.”

Mr. Frank nodded. “Perfect. Kids need to know that objects transfer energy in the same direction.”

“Finally, said Ms. Sneed, “kids explore bank shots. While more sophisticated, this gives them a sense of what happens when an object strikes at an angle. And it integrates math and science.”

“All of this provides more structure for collisions in physics than what we did last year,” said Ms. Sneed.