In some SUVAT questions, they ask for 2 time solutions and I can only find 1. What am I missing?

Let's say we are trying to work out how long it will take for a ball to be caught after it has been thrown straight upwards. If we set the final displacement to be zero (S=0) and solve S=UT+0.5AT2, it appears that we only get one value for T. However, there will always be a step in your workings when you can cancel a T from both sides of the equation, for example: 5T2 = 100T can be simplified to 5T = 100. In this step, we miss out a solution that T=0! This corresponds to when the ball is just about to be thrown so is still in our hands (hence we have a solution for zero displacement!)

CI

Related Physics A Level answers

All answers ▸

A block of mass (m) is placed on a rough slope inclined at an angle (a) to the horizontal, find an expression in terms of (a) for the smallest coefficient of friction (x), such that the block does not fall down the slope.


People A and B are taking a lift of mass 500 kg which has constant acceleration and the force from the rope that pulls it is 7500 N. The scales where the people stand show a reading of 720 N and 500 N.


How come nuclei become more unstable the bigger they are?


What causes or reduces resistance in a material?