Acar wheels has diameter 0.8m. it takes 1 minutes to make one revolution. calculate its speed.
a measurement or reading taken back towards a point of known elevation, used to calculate the height of the surveying instrument (theodolite, transit, total station).light is known to behave in a very predictable manner. if a ray of light could be observed and reflecting off of a flat mirror, then the behavior of the light as it reflects would follow a predictable law known as the law of reflection. the diagram below illustrates the law of reflection.
in the diagram, the ray of light the mirror is known as the incident ray (labeled i in the diagram). the ray of light that leaves the mirror is known as the reflected ray (labeled r in the diagram). at the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror. line is known as a normal line (labeled n in the diagram). the normal line divides the angle between the incident ray and the reflected ray into two equal angles. the angle between the incident ray and the normal is known as the angle of incidence. the angle between the reflected ray and the normal is known as the angle of reflection. (these two angles are labeled with the greek letter "theta" accompanied by a subscript; read as "theta-i" for angle of incidence and "theta-r" for angle of reflection.) the law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
the equation of thermal stress is: stress =fa = -e a dt, where e is young's modulus, a is the coefficient of linear thermal expansion, and dt is the change in temperature.