31. Stopping power ( properly, " stopping force " ) has units of energy per unit length . 32. String instruments are tuned by varying the strings'tension because adjusting length or mass per unit length is impractical. 33. In other words, requiring the vectors be of unit length restricts the vectors to lie on the unit circle. 34. In the above expression, as, the number of oscillations per unit length of the sinc function approaches infinity. 35. In effect, spatial resolution refers to the number of " independent " pixel values per unit length . 36. In this case, the unit length is 1 and it points in the same direction as the longer vector. 37. Let us consider a point p on a surface M with ( possibly non-unit length ) normal n. 38. The overall ratio of the flag was changed to two units width by three units length ( 2 : 3 ). 39. In equilibrium, the net force per unit length acting along the boundary line between the three phases must be zero. 40. The Bennett pinch showing the total current ( I ) versus the number of particles per unit length ( N ).
