A Level Edexcel Physics Paper 1, Working As A Physicist, Core Practicals COMPLETE PAPER Q&A

1d collisions head on collisions sticking together ANSWER : mv - mv = collective mass x v 1d collisions in the same direction not sticking together ANSWER : mv + mv = mv + mv 1d collisions in the same direction sticking together ANSWER : mv + mv = collective mass x v 1d explosions ANSWER : mv + 0 = collective mass x v 1d recoil ANSWER : 0 = mv + mv Gun velocity will be negative as it is going back 2d collisions ANSWER : Total momentum in vertical component Total momentum in horizontal component Use momentums to find resultant vector Divide by combined mass to find velocity Use SOHCAHTOA to find angle of velocity 360 degrees = ANSWER : 2π radians Absolute uncertainty ANSWER : expresses the margin of uncertainty associated with a measurement e.g. ±0.02 Absorption of gamma through lead Geiger-Muller ANSWER : Measures count so divide by time to get count rate per second Large periods of time reduce count rate Absorption of gamma through lead method ANSWER : - change thickness of Lead between a gamma emitter and a Geiger Muller tube - plot a log graph of counts per second vs fitness Absorption of gamma through lead risk ANSWER : Limit radiation and contain contamination Do this by keeping distance, line of sight and time as doubling distance will quarter the intensity of the radiation Absorption of gamma through lead uncertainty ANSWER : Radiation is random and therefore uncertainty is random Therefore increasing time increases accuracy as would doing repeats of thickness and diameter measuring Accuracy ANSWER : A description of how close a measurement is to the true value of the quantity measured. An emf is induced ANSWER : When there is relative movement between a magnet and a coil An object being hit off the ground at an angle horizontal distance travelled ANSWER : Work out horizontal component of inital velocity Use d = horizontal velocity x time An object being hit off the ground at an angle time in air ANSWER : Consider vertical velocity = 0 Consider vertical component of initial launch using SOHCAHTOA Know acceleration is negative and dependant on the planet Use suvant to find t Double it as this motion is parabolic and thus half of the time An object thrown off a cliff distance it lands from the foot of the cliff ANSWER : Horizontal distance = horizontal velocity x time of flight Horizontal velocity is given Time may be given or worked out earlier using suvat An object thrown off a cliff magnitude of final velocity ANSWER : Vertical Velocity = u + at Horizontal Velocity is given in the question Use Pythagoras to find resultant An object thrown off a cliff time taken to reach ground ANSWER : Use suvat remembering u is 0 Angle in radians ANSWER : length of arc (s) / radius (r) Angular speed ANSWER : Angle turned/ time taken Angular speed and time period/frequency equations