Phys1003
Homework L1-L3
1. Please select all the equipment that use the mechanical energy as the source of energy from the
following items:
(A) Hydroelectric power station;
(B) Nuclear reactor;
(C) Wind mill;
(D) Solar cell
2. Hong Kong annual population growth rate is 0.8% in mid-2015. Current population in Hong
Kong is 7 million, how long it will take to reach population of 9 million? (assume the growth
rate remain the same)
(A)
3 years
(B)
31 years
(C)
62 years
(D)
87 years
(E)
310 years
3. (a) Find the increase in world population, from the graph in slide 7 of L2 notes, between 1960
and 2000 and the estimated increase from 2000 to 2050.
(b) What can you say about the increase and rate of increase of world population before and after
1990?
(c) Compute and tabulate the increase and percentage increase of population in 1950, 1960, 1970,
1980, 2000, and the projected percentage increase in 2020, 2040.
(d) If one assume the world population growth from 1950 to 2010 is in an exponential manner,
compute the annual growth rate
r
in this period.