Edexcel IGCSE Physics Latest Update Rated A+

Edexcel IGCSE Physics Latest Update Rated A+ average speed = distance / time v = d / t Standard Unit for mass (m) kilogram (kg) Standard Unit for distance (d) or displacement (s) metre (m) Standard Unit for speed (s) or velocity (v) metre/second (m/s) Standard Unit for acceleration (a) metre/second2 (m/s2) SMART PDF Standard Unit for Force (F) Newton (N) Standard Unit for time (t) Second (s) Standard Unit for gravitational field strength (g) Newton/kilogram (N/kg) Standard Unit for moment (Paper 2 Only) Newton metre (Nm) Standard Unit for momentum (p) (Paper 2 Only) kilogram metre/second (kg m/s) What does the gradient of a distance-time graph represent? Gradient or the slope gives the speed. Flat line means stationary, straight line means constant speed, curved line means accelerating Describe how to investigate the motion of a toy car - Set a ramp up so that the top of it is a certain height, h, above the desk, and the other end is fixed in place on the desk. - Measure the distance the toy car will travel down the ramp using a metre ruler. - Measure the time taken for the toy car to roll down the ramp using a stop watch. - As it is difficult to start and stop the watch at exactly the right time, the experiment is repeated five times so an average time can be calculated. - Divide the distance by the average time to calculate the average speed of the car. - To improve the accuracy of the experiment, light gates connected to electronic timers could be used as human reaction times will no longer affect the results. We still take multiple readings as the car may not have been released in exactly the same way each time. - An electronic timer that reads to more decimal places will give the answer to a greater level of precision. Acceleration = Change in velocity/time taken a = (v-u) / t