3.1.A.1Concept
An object's translational kinetic energy is given by the equation K = ½mv². It depends on the object's mass and on the square of its speed, and it is measured in joules (1 J = 1 kg·m²/s²).
ExampleCalculating kinetic energy1 / 3
A baseball of mass 0.145 kg leaves a pitcher's hand at 40 m/s. (a) Find the ball's translational kinetic energy. (b) The ball is later caught while moving at 20 m/s. Find its kinetic energy then.
Try it on paper first, then reveal each step to check your work.
Step 1 — Write the equation
K = ½mv². The mass is 0.145 kg and the speed is 40 m/s.