Recoil motion

When an isolated excited nucleus emits a y-ray, it recoils in order to conserve the momentum. As a result of the motion, the energy of the emitted y-ray is Doppler shifted to a somewhat lower value, which makes the absorption of that y-ray impossible by some other nuclei of the same species. The recoil motion of the source can, however, be compensated by moving either the source or the absorber in a direction such that the total momentum of the nucleus plus y-ray is zero. 

The direction of the electron recoil motion can be found by applying the momentum conservation law (see Figure 6.43) p = p + moU From a triangle OCD we can find... 

The incident ions cause recoil in the surface atoms. In studies of ionic liquids, only direct recoil - that is, motion in the forward direction - was measured. Watson and co-workers [56, 57] used time-of-flight analysis with a pulsed ion beam to measure the kinetic energies of the scattered and sputtered ions and therefore determine the masses of the recoiled surface atoms. By relating the measured intensities of the... 

A familiar illustration is the effort a pitcher must exert to make a fast pitch and the opposition the catcher must put forth to stop the ball. Similarly, the engine to make an automobile begin to roll must perform considerable work although, after it has attained a certain velocity, it will roll along the road at uniform speed if just enough effort is expended to overcome friction, while brakes are necessary to stop its motion. Inertia also explains the kick or recoil of guns and the tremendous striking force of projectiles. 

A recoil atom is an atom that undergoes a sudden change or reversal of its direction of motion as the result of the emission by it of a particle or radiation in a nuclear reaction. 

Brakes, Recoil. Mechanisms which control the recoil of weapons. The modern recoil brake is s hydraulic brake and consists of a piston which moves in a cylinder filled with oil. The recoil brake is attached to the weapon in either of two ways a) the cylinder is attached to the tube(gun barrel) and moves with it during recoil and counterrecoil, while the piston is fixed to the carriage b) the piston is attached to the tube and moves with it during recoil and counter recoil, while the cylinder is fixed to the carriage. In either case, when the tube recoils, there is relative motion betw the piston and the cylinder and the operation in both Cases is fundamentally the same... 

Cylinder, Recoil A cylinder with component parts designed to cushion the backward motion of a cannon by springs, or by the slow passage of air or fluid thru holes in the piston when the gun is... 

In the pulsed molecular beam studies, the results were used to calculate an impact parameter for the photodissociation process. From these impact parameters it was concluded that the recoiling CN fragment did not take the lowest energy path when it was departing from the halogen atom. Rather, because of strong impulsive motion, the trajectory that the CN rsdical... 

---