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Science Experiments
Experiments often conducted by students to test different scientific theories and hypotheses
11,111 Questions
Why are car bodies not made from a low density metal like magnesium?
The main reason is cost and the ability to mass produce bodies with existing manufacturing equipment. Safety is a major concern for magnesium and its alloys since it can ignite at temperatures you see in typical car crashes (imagine a body panel skidding across asphalt). Once ignited, it can burn in the presence of oxygen, CO2, or water making it almost impossible to extinguish in emergency situations.
The raw material cost is only part of the total cost differential. Most car manufacturers are equipped to efficiently handle giant rolls of sheet steel. Aluminum is a good alternative in that it can be formed similarly to steel, however it is still not as easy to work with. These differences incur additional tooling and die costs even with economies of scale. The added costs means that aluminum is usually only used on more luxury car bodies such as the Audi A8 as the consumer is less likely to pay more for aluminum on less expensive cars. It is expected that aluminum will see increased use in car bodies as gas mileage regulations force auto makers to reduce weight.
Other low density high strength metals like beryllium and titanium are prohibitively expensive to use in their pure form. As an alloy, they are usually combined with aluminum, thus still becoming more expensive than aluminum, but without providing as drastic of a weight reduction as compared to steel. These alloys are even harder to work with thus adding more tooling costs over aluminum.
Carbon-fiber is not a metal, however its low density and high strength make it desirable as a raw material for car bodies. Despite the high availability of carbon, the supply of carbon fibers is low, thus making it an expensive commodity. Furthermore, the molding of carbon fiber into panels and structural members can take hours compared to the few seconds needed to stamp a sheet metal part. Thus carbon fiber is not used for any mass produced bodies.
Plastic is also not a metal, but because of its light weight and ease of manufacture, it is often used for nonstructural components like body panels, bumpers, and trims.
What are the properties of plastic?
- Resistance to corrosion and chemicals
- Low electrical and thermal conductivity
- High strength-to-weight ratio
- Colors available in a wide variety and transparent.
- Resistance to shock
- Good durability
- Low cost
- Easy of manufacture
- Resistance to water
- Low toxicity
What type of experiment will you conduct on different liquids affect plant growth?
no it does not affect the growth of plants because the liquids are actually good for the plants.
Why do shadows change during the day?
Because the sun moves across the sky (the world spins around it)
The earth rotates around the sun causing different shadow lengths
What is an example of conduction?
An example of conduction is a metal spoon in a cup of hot water.
an electric current flowing through water
The process in which compounds are converted to oxides by heating them in the air is called?
roasting
independent variable
Independent - the type of shoe
Dependent - the height of the jump
Control - the person doing the jumping
The information collected during an experiment is called blank?
The information collected during an experiment is called data. Scientists make observations to help them make a hypothesis or collect data during an experiment.
What is the problem that a lab activity is designed to solve called?
The question we answer is the problem.
Why does it make sense for scientists to test just one variable at a time in an experiment?
Because if you change more than one variable, you won't know which one was responsible for any observed effect, or indeed whether they both had a part in it. The worse case of all would be if they both had an effect but the effects cancelled out.
What was the purpose of the gauze in the experiment using meat in a jar?
The purpose was so the flies won't get in the jar.
Water carbon dioxide alcohol glucose oxygen which substance is an element?
The only element in that list is oxygen. The others are all compounds. When you look at the formulas: H20, CO2, C6H12O6 it becomes obvious that there is more than one type of atom, whereas O2 has only one type of atom.
What is a control group for a science fair project with stains and detergent?
a control group is a sample that is treated like the other experimental groups except that the independent variable isn't applied to it
Why is it so important to control variables in an experiment?
You need to control variables in an experiment so as to make sure that only the variable you are testing and changing is the one affecting the results of your experiment. For example, in an experiment to find the effect of light intensity on the rate of photosynthesis of plant, you'll change light by putting a plant in sun and another in dark but you must not change carbon dioxide level for both plants so by that you have controlled other variables in the experiment(variables which must be the same always in the experiment).
What are facts about the line of reflection?
Given a line L and a point P. Reflection P' of P in L is the point such that PP' is perpendicular to L, and PM = MP', where M is the point of intersection of PP' and L. In other words, P' is located on the other side of L, but at the same distance from L as P. P' is said to be a mirror or symmetric image of P in L. The line L is called the axis of symmetry or axis of reflection.
P' exists for any P. Let's write SL(P) = P'. If P' = SL(P), then P is the reflection in L of P':P = SL(P'). So that repeated reflection does noting: it does not move a point. Formally,
SL2 = I,
Where I is the identity transform. SL(P) = P, iff P lies on L.
The reflection transform SL applies to arbitrary shapes point-by-point. Each point of a given shape S is reflected in L, and the collection of these reflections is the symmetric image of S: SL(S). To determine SL(S) when S is a polygon, suffice it to reflect its vertices. This is exactly what has been done in the applet below.
On the other hand, if S' is known to be a mirror image of S, then any pair of points P and P' not fixed by the reflection (P ≠ P'), the axes of reflection is uniquely determined as the perpendicular bisector of PP'.
In the applet, you can create polygons with a desired number of vertices, drag the vertices one at a time, or drag the polygon as a whole. Axes of reflection can also be dragged. They rotate if dragged near the applet's border, or translate if dragged nearer their midpoint.In a redox reaction the numbers of some of the elements changes from the reactants to the products?
In a redox reaction the OXIDATION numbers of some of the elements change from the reactants to the products. The numbers of atoms each element never changes in any chemical reaction.
What could be catchy title name for my science fair project does age affect lung capacities?
Breath In, Breath Out
In and Out
What is the van't Hoff factor for AlCl3?
The van't Hoff factor for AlCl3 is 4. AlCl3 dissociates into Al3+ and 3Cl- ions when it dissolves in water, resulting in a total of 4 ions in solution per formula unit of AlCl3.
