AQA physics paper 1 - mock exam

A heating element of a kettle was connected to the mains supply. Explain why the temperature of the heating element increased. - correct answearsElectrons collide with particles inside the heating element Which increases the kinetic energy of the particles A scientist cooled the air inside a container. The air contained water that froze at 0°c. The change in internal energy of the water as it froze was 0.70kJ. The specific latent heat of fusion of water is 330kJ/kg. Calculate the mass of ice produced. - correct answears0.70 = m x 330 m = 0.70/330 m = 0.0021 A scientist cooled the air inside a container. The temperature of the air changed from 20°c to 0°c. The volume of the container stayed the same. Explain how the motion of the air molecules caused the pressure in the container to change as the temperature decreased. - correct answearsPressure decreased Molecules have less energy Fewer collisions with the walls of the container A student investigated how the mass of water in and electric kettle affected the time taken for the water to reach boiling point. The kettle switched off when the water reached boiling point. Give one variable that the student should have controlled. - correct answearsStarting temperature of the water Name the type of relationship between current and potential difference for a resistor at constant temperature. - correct answearsDirectly proportional Oxygen boils at -183°c and freezes at -218°c Nitrogen boils at -195°c and freezes at -210°c Carbon dioxide sublimates at -7