countertorque
Countertorque is the torque that acts in the opposite direction to an applied torque, reducing or opposing the resulting angular acceleration of a rotating body. In rotational dynamics, the net torque on a body equals the product of the moment of inertia and the angular acceleration (tau = I * alpha). A countertorque may be introduced to achieve equilibrium (alpha = 0) or to limit rotational speed, stabilize motion, or control thrust impulse.
Sources of countertorque include reaction torques in handheld tools, recoil management in firearms, braking torques in
Design and control of countertorques involve balancing effectiveness with energy, weight, and vibrations. Excess countertorque can
See also: torque, angular momentum, equilibrium, reaction torque, counter-rotating systems.