Work and Kinetic Energy (Physics)

Recall cards on work and kinetic energy: work as the transfer of energy when a force acts through a displacement, the infinitesimal work dW = F.dr, the constant-force result W = Fd cos(theta), the parallel-component rule, work as a line integral or the area under a force-versus-displacement curve, the sign of work, the joule and foot-pound, and the work done by friction, gravity, and a spring, including conservative versus dissipative forces and the zero work around a closed path. Kinetic energy K = (1/2)mv^2 as a non-negative scalar that depends on speed and reference frame, its joule unit, the momentum form K = p^2/(2m), and translational versus rotational kinetic energy. The work-energy theorem W_net = K_f - K_i derived from Newton's second law, its use for variable forces and curved frictionless paths, and the consequences of positive, negative, and zero net work. And power as the rate of doing work, average power W/t, instantaneous power dW/dt = F.v, the watt, and the horsepower.