In an experiment to measure the quantum yield of a photochemical reaction, the absorbing substance was exposed to 490nm light from a 100w source for 45 min. the intensity of the transmitted light was 40% of the intensity of the incident light. as a result of irradiation, 0.344 mol of the absorbing substance decomposed. determine the quantum yield. (hint (1) calculate the total energy delivered to the source, (2) calculate the energy delivered by 490nm radiation per photon, (3) then calculate the number of photons, (4) then calculate the number of photons absorbed in mol and finally (5) you can calculate the quantum yield. the quantum yield is:
a) .89
b) .67
c) .52
d) .42

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Definitely true