The Viscosity of Motor Oil Alicia Alderman 5th Period 12/6/13

Question Does the viscosity of motor oil change at different temperatures?

Background The reason I picked this topic is because my dad is a mechanic for ODOTand he works on cars all the time at his shop. I saw this experiment online and thought it would be something that he could help me with!

Variables Independent: The temperature of the motor oil. Dependent: What I observe with the viscosity of the motor oil. Controlled: Using the same golf ball, using the same amount of motor oil in the same container, and the same leveled surface to do experiment.

Hypothesis If I heat motor oil then the viscosity of the motor oil will change.

Materials 2 containers, thermometer, and tongs. 2 quarts of motor oil (10W-30). 1 golf ball. 1 stop watch (On IPhone).

Procedure Put a quart of motor oil in each container. Measure the temperature of oil in each container. In the container not heated (container 1) drop the golf ball into it and measure the time it takes to reach the bottom. Take container 2 of motor oil and heat it slightly and measure the temperature with a thermometer. Drop the same golf ball into the second container and measure how many seconds it takes to reach the bottom. Heat the motor oil some more in container 2 and repeat step 5. Graph results

Data 950 ml 68 F 43 sec. 77 F 40 sec. 122 F 32 sec. Container 1:

Conclusion The question asked was does the viscosity of motor oil change at different temperatures. I used two containers with 950 ml. of motor oil. The first container I put in the refrigerator for about 2 hours. The second container had the motor oil at room temperature and then later it was heated. I dropped a golf ball into each container and measured the time in seconds it took to reach the bottom of each container. The colder the motor oil the longer it took to reach the bottom. As the oil was heated the quicker the golf ball dropped to the bottom. My data proved my hypothesis to be true. The viscosity of motor oil changes when it is heated. I learned that motor oil gets thinner as it gets hotter. I had a few problems with this experiment. My first problem was timing the ball as it dropped. It took me a few trials before I got it. It dropped fast. The second problem was realizing you can’t heat motor oil in the microwave but on the stove. My dad helped me understand that motor oil heats by friction. My last problem was that motor oil is hard to clean up. Even though I had a few problems I enjoyed doing this experiment and proving my hypothesis to be true.