Slow the Flow, Joe!

Slow the flow, Joe!

When we talk about the speed of something, we are measuring how far something moves in a certain amount of time. That means we are measuring how slowly or quickly an object changes position. So if a friend and you are riding a bike together from your home (the same starting point), that friend might get to the store (the final destination) faster than you because of their speed.

For this exploration, the calculation for speed is: or .

Butcan the speed of an object change if it interacts with a liquid?

Write your prediction to the question in the space provided and give examples you have experienced to support your answer.

______

Procedure:

At your lab station you will find three graduated cylinders with different liquids. You will calculate the speeds of the objectas it travels through the liquids to decide if the speed is affected.

(1)With your lab partners, observe, discuss, and list the physical properties of each of the substances in the graduated cylinders.

Physical Property / A / B / C

(2) Predict in which cylinder (if any) the sphere might move the slowest. Explain the reasoning for your answer.

______

(3) Measure the height of the column of liquid (it should be about 1 cm. from the top of the cylinder to prevent overflow during the exploration) and record it in the data chart. Important: Before each trial, ensure the height of the column of the substance is the same.

(4)One person in the group will place the sphere between their thumb and index finger and rest their fingers on the lip of the cylinder.

(5)While a lab partner measures the time it takes from the release of the sphere untilit travels to the bottom, drop the sphere into the liquid.

(6)Record the time measurement in the data table.

(7)Empty the liquid and sphere into the beaker, retrieve and clean the sphere, pour the liquid back into the graduated cylinder, bring the liquid level to the original height, and repeat the exploration two times.

Cylinder A
Trial / Liquid Height (cm.) / Time
(s) / Speed
(cm/s)
1
2
3
Average Speed
Cylinder B
Trial / Liquid Height (cm.) / Time
(s) / Speed
(cm/s)
1
2
3
Average Speed
Cylinder C
Trial / Liquid Height (cm.) / Time
(s) / Speed
(cm/s)
1
2
3
Average Speed

(8)Create a bar graph to represent the average speeds.

(9)By interpreting your graph, write a sentence conclusion regarding the speed of an object as ittravels through a liquid? Explain your answer by including data obtained from your exploration.

______

(10)Refer back to your list of physical properties. Can you identify any correlation in your observed physical property(ies) to its/theireffect on the speed of the sphere in the liquid? If the answer to question is “yes”, complete the relationship statement by entering the characteristic(s) in the blank and circling an option within the parentheses.

If the ______of the liquid (increases, decreases) then thespeed of the object (increases, decreases, stays the same).

If the ______of the liquid (increases, decreases) then the speed of the object (increases, decreases, stays the same).