A 2.67 kg block slides down a frictionless plane, from rest, with an acceleration of 5.48009 m/s^2. What's the block's speed (in m/s) after travelling 2.1 m along the incline?
The facts that the block is going down a plane is not so important. The important thing is that the plane is frictionless.
The two laws of the accelerated motion are:
But if you solve the system of the two equations, you can find a third law really useful in those cases in which you haven't the time, or you haven't to find it.