How do I use equations of motion ('suvat') to find a missing quantity?
First, be familiar with the equations of motion:s = displacementu = initial velocityv = final velocitya = acceleration (constant)t = time
v = u + ats = ((u+v)t)/2s = ut + (at^2)/2v^2 = u^2 + 2as
Second, identify which 3 values are given in the question (remember that if it's motion under gravity then a=9.8 ms^-2).
Finally, identify which equation to use and plug in the values. Pick the equation that has the 3 known values and the unknown value. Then solve the equation to find the unknown quantity.
e.g. Q) A ball is fired out of a pinball machine at 4ms^-1. After travelling 1.5m with a deceleration of 0.5ms^-2, what is it's final velocity?
A) u=4, s=1.5, a=-0.5, v=?v^2 = u^2+2asv^2 = 4^2 + 2(-0.5)(1.5)v^2 = 16 - 1.5v^2 = 14.5v = 3.81 ms^-1
JH
Related Physics GCSE answers
All answers ▸Two cars are moving parallel to each other on a road. The first car is moving at a speed of 11 m/s, while the second car is moving at 17 m/s, what is the speed of the second car, relative to the first car.
Explain the process of nuclear fusion in the Sun.
How do you calculate the total resistance of two resistors, R1 and R2, when they are in series and when they are in parallel?
A mass of 2kg is dropped from rest at a height of 10m. i) What is the initial GPE of the mass? ii) What is the final velocity of the mass when it hits the ground?