energy forms and transformations test answers (usa test prep. 1.)
(roller coasted dotted looking graph) The graph represents the cooling curve of ethyl alcohol. Determine the boiling point of ethyl alcohol.
80°C
Which is an example of electrical energy being converted or changed into light energy?
a light bulb
Heat would best be transferred by conduction between
a stove and a copper pot.
In the graph, a sample of water is heated from 40 degrees Celsius to 100 degrees Celsius. Which statement correctly describes the curve?
a) QR- liquid only RS- phase change liquid-gas ST- gas only
As temperature of this substance rises from 20°C to 50°C, the substance _______ heat and its kinetic energy _________ .
absorbs; increases
When gasoline is burned in a car engine, ________ energy is converted into _________ energy.
chemical, mechanical
the name for heat transfer between two solids which are in direct contact or touching one another is
conduction.
The heat transfer depicted in the image is MOST likely (Two clouds, hot going in cold going out)
convection
Substance Specific Heat (J kg-1 K-1) Aluminum 900 Copper 390 Brass 380 Silver 230 Platinum 130 Which sample of copper would demonstrate the GREATEST increase in temperature if 500 J of energy were added to the sample?
0.5 kg
Which energy transformations BEST illustrates why people can walk?
Chemical energy is being converted into mechanical energy.
Why does a metal spoon left on a bowl of hot soup become warm?
Metal produces its own heat.
Expansion amounts for 50 cm of each of the solids: brass alloy: 0.11 cm aluminum: 0.07 cm iron: 0.12 cm steel alloy: 0.04 cm Each strip of metal was the same thickness and was heated to 100°C. Based just on the data, which conclusion can be drawn?
Metals expand upon heating
Which is the MOST accurate statement about the heating curve and energy?
Moving from A to C the temperature and the kinetic energy increases.
substance Specific Heat (J kg-1 K-1) Aluminum 900 Copper 390 Brass 380 Silver 230 Platinum 130 If 130 J of energy were added to 1 kg of each of these samples, which would experience the GREATEST temperature increase?
Platinum
Microwave ovens heat food through the process of
Radiation
The method of heat transfer by which the sun energy reaches the earth is
Radiation
Substance Specific Heat (J kg-1 K-1) Aluminum 900 Copper 390 Brass 380 Silver 230 Platinum 130 Explain why a Chef in a very busy restaurant would prefer a copper pot over an aluminum pot.
The copper pot would heat faster because it has a lower specific heat value
Which example involves the transformation of chemical energy directly into light energy?
a glow stick
A generator converts mechanical energy into _____________________ energy.
electrical
The law of conservation of energy states that
energy may neither be created nor destroyed; it may only be transformed.
Substance Specific Heat Capacity J/Kgo C Ammonia 4700 Ethanol 2440 Gasoline 2220 Water 4186 500 ml of four different liquids are heated to 50oC. According to the specific heat data, which liquid will cool to 35oC in the shortest amount of time?
gasoline
Maria's father started a fire in the fireplace. He crumpled some paper, lit a match, and soon the logs in the fireplace were burning. In this case, the stored chemical energy in the logs was changed into
heat and light energy.
Energy is transferred in solids by conduction, which means that
heat travels from the hotter object to the cooler object.
A solar powered car converts _______________ energy into _________________ energy.
light, mechanical
Muscles convert chemical energy into
mechanical energy
The graph shows the cooling curve of a substance. At which point does the substance begin to melt?
p
It is generally seen that, when a substance absorbs heat energy, its heating curve shows two plateaus. Which phenomenon is indicated by these plateaus?
phase change
As a roller coaster goes downhill
potential energy is converted into kinetic energy
An example of friction being converted into heat energy is
rubbing your hands together.
Which is an example of nuclear energy being converted into heat and light energy?
the sun
