Question 15:
A primary root grows from 5 cm to 19 cm in a week. Calculate the growth rate and relative growth rate over the period.
Growth is dependent on three factors -initial size (W0), rate of growth (r) and time interval (+) for which the rate of growth is retained.
W1=W0ertW1=final size,W0=Initial size,r=growth rate,t=time,e=base of natural logarithm.19=5×(2.7)r×7195=(2.7)r×73.8=(2.7)r×7log 3.8=r×7×log(2.7)0.5798=r×7×0.43140.57987×0.4314=r=0.1907Relative growth rate=Growth in given time periodMeasurement at start of time period =195=3.8cm
Thus absolute growth rate is 0.1907 while relative growth rate is 3.8cm.