Why isn't kinetic energy a vector instead of a scalar?

For a vector quantity to be fully defined, it needs: 1. Direction 2. Magnitude 3. Point of action. A scalar quantity only needs a magnitude to be defined. read more

Kinetic energy is a scalar because it is defined to be a scalar. The reason why scientists define certain words to mean certain things is that some definitions are more useful than others. In particular, if a quantity is useful, it is likely to have a name. read more

Kinetic energy does not use velocity in the equation you stated. That equation uses speed, the magnitude of a velocity vector. Since the magnitude of a vector is a scalar, there is no vector term in the kinetic energy equation. read more

Kinetic energy is a scalar. Energy itself is a scalar quantity. If we are going to look at the equation which is KE=(1/2)mv^2 we knew that mass is a scalr quantity and velocity is a vector quantity. read more