physics paper 2 marks schemes

'a non contact form acts on each magnet' - answer-magnets aren't touching but both experience a force describe how to plot the magnetic field pattern of a bar magnet - answer-place a compass near the north pole of the magnet and mark the direction that the compass points move the compass around the bar magnet to the other pole, marking at intervals the direction the compass points join the points up and add an arrow pointing from the north poe to the south pole explain the effect on the motion of a ball bearing when the switch is closed - answer-closing the switch causes a current in the coil a magnetic field is created a force of attraction acts on the ball bearing so the ball bearing accelerates towards the iron nail force = - answer-mass x acceleration transverse wave - answer-the oscillation/ vibration is perpendicular to the direction of energy transfer why is it difficult to make predictions based on some hypothesises - answer-they don't say how increasing or decreasing the force increases or decrease the acceleration list of equipment used in trolley ramp investigation - answer-newton metre (force) ticker timer + tape (change in velocity and time) why use a sloping runway - answer-reduce effect of friction on trolley why us the same trolley through the investigation - answer-so that the mass is constant as changing the mass would change the acceleration so there is only one independent variable highest frequency electromagnetic - answer-gamma rays what microwaves suitable for for sending comms to a satellite in space - answer-can travel through the atmosphere what events lead to a neutron star forming - answer-explosion of a red super giant or supernova 1GHZ = - answer-1x10^9 HZ if an alternating current is created, what frequency would it have - answer-same as the radio wave why does a star remain stable - answer-expansion due to fusion energy is in equilibrium with gravitational collapse what happens to the sun between it leaving the main sequence group and becoming a white dwarf - answer-sun goes from main sequence to star to red giant then from red giant to white dwarf. when the sun changes to a red giant, the surface temperature will decrease and the relative luminosity will increase when changing from a red giant to a white dwarf, the surface temperature increases and the relative luminosity will increase difference between vector and scalar quantity - answer-a vector has a direction but a scalar does not example of vector quantity - answer-velocity force weight acceleration displacement momentum - answer-mass x velocity unit of momentum - answer-kg m /s effect of time of contact with ball and distance ball travels - answer-longer time of contact the greater the change of momentum since the mass of the golf ball is constant, the velocity of the golf ball must increase, which increases the distance the ball travels