What is a misconception on density?
When 9th graders enter high school, some may hold several misconceptions about density. Here are some examples: • “An object, such as a boat, floats because water is pushing up on it.” • “The weight of an object determines if it will sink or float.
How to think about density?
The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre. For example, the density of water is 1 gram per cubic centimetre, and Earth’s density is 5.51 grams per cubic centimetre.
What did I learn about density?
Density measures the mass of an object or substance compared to its volume. The equation we use to find density is: density = mass / volume. If an object is heavy and compact, it has a high density. If an object is light and takes up a lot of space, it has a low density.
What can affect density?
The density of an object can change if either the mass or volume of the object is changed. Fluids, such as water, have a certain density. If an object is more dense than water, it will sink; if it is less dense than water, it will float.
What are children’s misconceptions about sink and float?
Misconceptions. The main misconception however, about floating and sinking is concerned with the weight and size of the object. Many children believe that if two objects are the same in weight then they must both either float or sink. This is incorrect as density determines whether an item float or sinks.
What is density in your own words?
Density describes how compact or concentrated something is. For example, suppose you have two boxes, one large and one small. However, they both weigh the same. That means the small box has a higher density than the large box. Density also tells how concentrated or crowded something is.
What’s a non example of density?
Everyday Density Examples A Styrofoam cup is less dense than a ceramic cup, so the Styrofoam cup will float in water and the ceramic cup will sink. Wood generally floats on water because it is less dense than water. Rocks, generally being denser than water, usually sink.
How does density affect our lives?
A Styrofoam cup is less dense than a ceramic cup, so the Styrofoam cup will float in water and the ceramic cup will sink. Wood generally floats on water because it is less dense than water. Rocks, generally being denser than water, usually sink. This obvious example illustrates the power of science in real life.
Why does density not change?
However, the density does not change. This is because the mass and volume increase at the same rate/proportion!
Why do some materials float in water and other sink?
Key Concepts The density of an object determines whether it will float or sink in another substance. An object will float if it is less dense than the liquid it is placed in. An object will sink if it is more dense than the liquid it is placed in.
Why do some objects float on water and some sink?
The positioning of molecules affects the density of an object. Objects with tightly packed molecules are more dense than those where the molecules are spread out. Density plays a part in why some things float and some sink. Objects that are more dense than water sink and those less dense float.
What factors do you think may cause your densities values to be different from the actual values?
The most common reasons for density errors include using the wrong or inaccurate instruments and not accounting for temperature changes.
What causes differences in density?
A density difference can exist between two fluids because of a difference in temperature, salinity, or concentration of suspended sediment. Density currents in nature are exemplified by those currents that flow along the bottom of oceans or lakes.
How does density affect your daily life?
Is water more dense than oil?
Since the oil is lighter, it is less dense than water and floats on water.
What are some common misconceptions about density in high school?
When 9th graders enter high school, some may hold several misconceptions about density. Here are some examples: • “An object, such as a boat, floats because water is pushing up on it.” • “The weight of an object determines if it will sink or float. Heavy objects always sink, and light objects always float.” • “Objects with holes in it will sink.
Are smaller objects less dense than larger objects?
That’s the only exception.” • “The smaller something is, the less density it has. So smaller objects are less dense than larger objects.” • “If you cut a piece of wood in half, the density of each piece is now half of the original piece.” • “Density is the thickness of something.
How can teachers help students understand density?
If students are to understand the concept of density and, in many cases, give up their stubbornly held prior misconceptions, teachers should know that in spite of giving an in-depth lecture on density, the authority of the teacher is not be enough to change stu- dents’ misconceptions.
What is a misconception?
When a student holds ideas and notions that are in conflict with the scientific explanation, the ideas are frequently labeled as misconceptions. The term misconceptionmay be misleading since the student will probably, in time, change his or her presently held understanding to the scientifically accepted form.