DSA Exam 2023 with 100% correct questions and and answers

What is the energy of motion? Kinetic energy What are three factors that affect an object's gravitational potential energy? Mass, height, and acceleration due to gravity What type of energy increases as an object becomes warmer? thermal what type of energy is stored in substances like fuel, oil, propane, and gas? chemical If you walk or run, _____ energy is converted to _____ energy chemical, mechanical Nuclear power plants convert _____ energy to _____ energy nuclear, electrical Solar cells convert _____ energy to _____ energy electromagnetic, electrical What are three things that can be said about energy creation, destruction, and conversion. The law states that energy can't be created or destroyed. Energy can be converted. In a close system, the amount of energy presented at the beginning of a process is the same as the amount of energy at the end. What are two components of mechanical energy? potential and kinetic energy Describe biomass energy Biomass energy is the chemical energy stored in living things. what are nonrenewable energy sources? name 4 uranium, coal, oil, natural gas What are two big reasons why fossil fuels are used to supply the most energy in the world? Fossil fuels are somewhat _____ and _____. inexpensive, readily available Name a drawback of solar energy the sun isn't always out What is a benefit of the hydrogen fuel cell? non-polluting If you place a metal spoon in a cup of coffee, what is the main manner in which thermal energy is removed from the coffee? Thermodynamics. the second law states that thermal energy can flow from colder objects to hotter objects if work is done on the system What causes the transfer of thermal energy from one object to another? Convection is the transfer of thermal energy with no overall transfer of matter What type of energy increases as the temperature of an object increases? Thermal energy By what process does the sun's energy reach earth? Conduction, radiation, or convection? radiation What type of material allows electrical charges to flow easily? electrical conductor What two processes of transferring thermal energy need mass ? Convection and radiation Describe the process by which electricity is converted to light energy in a light bulb Electrons move through filament, heats up, glows, gives light What are three important factors that will affect the electrical resistance of a material? thickness, length, and temperature Give three ways that you could reduce the resistance of a metal wire Make a wire thicker, having a shorter wire, cool to low temp. (superconductor) Give three versions of ohm's law V=IxR, I=V/R, R=V/I Describe how electrical charges can create a magnetic field when charges move negative to positive (electromagnetic wave) If you had a coil of wire, how could you increase the ?voltage being induced in it by a magnetic field? Move the coil of wire more quickly and move the magnet inside Why do you think the usage of coal decreased and the usage of nuclear power increased in CT starting in the 1960's? They wanted something more efficient, coal is dirty Why would nuclear power usage have lots of peaks and valleys over the years? It's efficient, but costly How would you have improved your solar cooker? plexi glass because serran wrap wouldn't stay and we lost heat. light goes through serran wrap and helps it absorb more ! smaller box inside to trap heat better, and i would add mirrors as reflective surfaces because foil rips easily What variables did you hold constant in your testing? distance from lamp to beaker, amount of water, type of lamp, same dimensions of box, 50 mL of water, same thermometer, tested every 5 min. big control - heat lamp hitting beaker