v=u+at and s=ut+½at² apply for constant acceleration.
For constant acceleration: v=u+at, s=ut+½at², v²=u²+2as, s=(u+v)t/2. They only apply when a is constant. Free fall near Earth uses a=g.
A car braking at 8 m/s² from 20 m/s stops in 20²/(2×8)=25 m.
These equations let you solve constant-acceleration problems quickly, such as braking distance or the time for a drop test.
v=u+at and s=ut+½at² apply for constant acceleration.
These equations let you solve constant-acceleration problems quickly, such as braking distance or the time for a drop test.
No. They apply only to constant acceleration, so split the motion into intervals with constant acceleration or integrate the changing one.
Use the one that relates velocity and displacement without time, v squared equals u squared plus 2as.
Typical applications include calculating the stopping distance of a car with constant braking, finding the speed of a falling object before impact and estimating the launch speed of a ball from its flight time.
Study "Kinematics of a particle" first (topic 21 of 106 in Engineering Mechanics). It covers the groundwork this topic builds on.
Choose a sign convention. List known and unknown quantities. Not valid if a varies.
A car braking at 8 m/s² from 20 m/s stops in 20²/(2×8)=25 m.
The next topic is "Projectile motion", which builds directly on this one.
It is classed as Beginner in Engineering Mechanics (topic 22 of 106). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.