Practice paper Mye 2022 Flashcards
Energy conversion in an electric kettle
electrical energy -> heat
Energy conversion pulling on an extension spring balance
chemical potential energy (→kinetic energy)→elastic potential energy
Energy conversion when cycling uphill
chemical potential energy→kinetic energy→gravitational potential energy
Energy conversion when generating electricity by burning fossil fuels
chemical potential energy → heat → kinetic energy → electrical energy
Describe what happens to the atoms during the chemical reaction, and explain why this is considered a chemical change
The atoms of the reactants are rearranged during a chemical reaction (1) to form new products (1)
State what can be concluded about the mass of the chemicals during the reaction.
The total mass of the chemicals remain the same OR do not change during the reaction.
Explain how the wind blowing insecticide from a field in the forest causes the number of sparrow decreases (Note: flies which it eats are killed)
Source of food, flies is killed of by insecticides
Explain how the wind blowing insecticide from a field in the forest causes the number of mice to increase
Less competition of food from the tree
Explain how the wind blowing insecticide from a field in the forest causes a larger decrease in the number of sparrow hawks than snakes
Sparrows is the only source of food for the sparrow hawks so the decrease in sparrows will impact sparrow hawks the most
Snakes have an alternative source of food – mice, which is unaffected with insecticide
Define weight
Weight is the gravitational force that the planet exerts on an object OR
force of gravity exerted on an object that pulls it towards its centre.
Suggest why suction cups may not be as effective in securing the cameras on Mars.
The force due to the atmospheric pressure may not be sufficient to hold the suction cup
To launch a spacecraft, it needs to escape from the force of gravity holding it to the surface. Suggest two advantages if Perseverance rover was launched from the Moon, rather than from Earth.
- (…) easier to escape from force of gravity on moon than on the earth
- Rover may be able to carry more load and still be launched on the moon. This may not be possible on earth
Explain whether there will be a difference if the leaves are tightly packed.
Yes, With tightly packed leaves, there is a reduction of layer of air [1]
so food may not stay warm for a long time [1]
Describe how the water in the kettle is heated by the heating element.
When the water near the heating element is heated up, it expands and becomes less dense, and rises to the top.[1]
The cooler water (at the top) is denser and sinks to the bottom, and gets heated up. [1]
The cycle continues and a convection current is set up to heat all the water in the kettle. [1]
State two additional advantages of using the white plastic kettle as compared to the kettle made of black stainless steel.
Plastic is a poor conductor if heat so the surface would be cooler to touch than stainless steel. [1]
white is a poor emitter(radiator) of heat so the water will stay warm for a longer period of time. [1]
