How many drops of water can fit on a penny lab?
We had 27 drops of water on ours! Surface tension and cohesion is the reason you can get so many drops of water on a penny. Cohesion is the “stickiness” of like molecules to one another. Water molecules love to stick together!
What is the independent variable in the drops on a penny lab?
The independent variable in the experiment is the soap and the dependent variable in the experiment is the number of water drops on the surface of the penny. The control is the penny without soap.
Can be tested by putting drops on a penny?
The cohesion and surface tension of water becomes apparent when the drops of water you add to the penny reach the penny’s edge. Once the water has reached the edge, you begin to see a bubble or dome of water forming on top of the penny.
Why do water droplets stay on pennies?
The attraction of water molecules to other substances, like soil or glass, is called adhesion. As drops of water are added onto a penny, the adhesive force between the water and the penny keeps the water from falling off.
What is a dependent variable in a penny experiment?
#1. The independent variable in this experiment was the side of the penny. #2. The dependent variable in this experiment was the number of drops on a penny.
What effect does the side of a penny have on the number of drops it can hold?
The results indicate that when you drop water on a penny that the heads side of the penny will hold more drops (heads 23 drops, tails 18 drops).
How do you get more drops of water on a penny?
Procedure
- Fill the medicine dropper with water.
- Now carefully add one drop of water at a time to the top of the penny.
- Keep adding drops (refill your medicine dropper as necessary) one at a time.
- Once the drop spills over the penny’s edge, use a towel to completely dry off the penny and surrounding surface.
How does surface tension work on a penny?
When plain water is dropped on a penny, water molecules strongly attract one another and the resulting surface tension is high. This is observed by the bubble-like shape formed by the water as more drops are added to the penny’s surface.
How do you make a physics lab out of a penny?
For this physics lab you will need: 1. Set the penny on a level surface. 2. Draw water into the eyedropper by squeezing the bulb at the top, then placing the tip into your container of water and releasing it. 3. Carefully place one drop at a time of water onto the surface of the penny, counting each drop as you go.
How do you count water drops on a penny?
Carefully place one drop at a time of water onto the surface of the penny, counting each drop as you go. Observe the collection of water on the penny getting larger and larger.
Can I use an eyedropper to clean a penny?
Be careful not to touch the tip of the eyedropper to the water as you drop it onto the penny. This might make it spill sooner!