Vector and scalar judge whether to follow the parallelogram law. What follows the parallelogram law is a vector, and vice versa is a scalar.
Vector: all forces (gravity, elasticity, friction, electric field force, magnetic field force and Lorentz force), speed (average and instantaneous), speed change, acceleration, displacement, momentum, momentum change, impulse, linear velocity, angular velocity, pressure, electric field strength, magnetic induction strength and torque.
Scalar: speed, mass, density, time, volume, work, energy, power, electric quantity, current intensity, voltage, resistance, electromotive force, magnetic flux, magnetic flux change, magnetic flux change rate, temperature, material quantity and light intensity.
Vector is solved by parallelogram rule, and scalar is solved by general mathematical operation.