SpillNot - Centripetal Force (Jovanny Navarro)

Author

Jovanny Navarro

Principles

Centripetal Force

Standards

MS-PS2-3

Plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object.

Materials needed

SpillNot

Beaker

Water

Food Coloring

Procedure

1. Fill a beaker with 250mL of water along with a few drops of food coloring.

2. Have a student volunteer move the beaker from one side of the room as quickly as possible while being timed.

3. Have the rest of the class observe and explain why it took so long for the student volunteer to get to the other side (the water was spilling).

4. Refill the beaker with 250mL of water and a few drops of food coloring.

5. Place the beaker on the SpillNot contraption.

6. Have the same student carry the water as quickly as possible once again.

7. Have the rest of the class observe any differences.

Explanation

When the student first carries the water across the room, some of the water spills due to inertia. The water wants to stay in place even though the beaker is moving causing it to spill. However, when the beaker is placed on the contraption, the beaker also tries to stay in place when the student moves. The contraption causes the beaker to be pushed inward (or forward) causing the water inside to also be pushed and stopping it from spilling.

Questions

1. Why does the water spill during the first attempt?

The water spills because of inertia.

2. Why doesn't the water spill during the second attempt?

The water doesn't spill due to the centripetal force acting upon it. The SpillNot provides an inward force which acts upon the beaker and the water within it.

3. Where else in the real world can we see centripetal force being applied?

Answers will vary. Student examples: roller coasters, a car making a turn, spaces.

Everyday examples of the principles illustrated

1) We experience centripetal force when driving. As the car begins to turn, we feel the car pulling us inward.

2) The force we feel when going through a loop while on a roller coaster is another example of centripetal force.

Photos