SUBJECT: GEOGRAPHY
CLASS: SS1
DATE:
TERM: 1ST TERM
REFERENCE MATERIAL
- Essential Geography for Senior Secondary Schools, O.A. Iwena.
WEEK FIVE
TOPIC: CALCULATION OF DISTANCES AND LOCAL TIME
Calculation of distance using lines of latitude
Procedures:
- locate the two places involved
- find the latitude difference between the two places
Note: North-North= subtract
North-South= add
South-North= add
Equator-North= add or subtract
Equator-South= add or subtract
- multiply the latitude difference by 111km
1°=111km( 1° of latitude is approx. 111km on land)
Example 1
Calculate the distance between S.Africa(30oS) and Spain(40oN)
Solution:
- i) Lat.diff.=30oS+40N=70o
since 1o=111km
therefore, 111×70=7770km
The distance b/w S.Africa and Spain=7,7770km
EVALUATION QUESTIONS
- What is the distance between place A (lat.20oS) and place B (lat.51oN)?
- What is the distance between the Equator and Lagos (14oN)?
Calculation of Local Time using the lines of longitude
Procedures:
- locate the places involved
- find longitude difference
- conversion to time
- adjust time according to the direction of movement(west or east)
Examples:
- If the time at town A(long.75°W) is 5.00pm on Friday, what will be the time and day at town B(long.120°E) ?
Solution:
- i) Long.diff.=75°+120°=195°
- ii) conversion to time=195 (since 15°=1hr)=13hrs
15
iii) adjustment of time according to direction of movt.=5pm+13hrs(add,since it is due east)=6.00am on Saturday
EVALUATION QUESTION
Explain how to use longitude to calculate local time
GENERAL EVALUATION
When it is 2.00pm at GMT; what is the time in
- Ethiopia (45oE)?
- Los-Angeles (75oW)?
- Nigeria (15oE)?
READING ASSIGNMENT
Essential Geography, O.A. Iwena, Pages 17-19.
WEEKEND ASSIGNMENT
- If the time at the Greenwich Meridian is 11.00 am, what would be the local time at a place 750 W? (a) 6:00am (b) 6:00pm (c) 7:00am
- Which of the following is not a characteristic of lines of longitude? They …… (a) converge at the poles (b) run from east to west (c) run from north to south
- Latitude 66 1/20S marks the…….. (a) Antarctic circle (b) Arctic circle (c) Tropic of cancer
- What is the approximate distance of town X from the equator, if it is located on latitude 140N? (a) 1232 km (b) 1555km (c) 1675km
- Which of the following planets has twelve satellites? (a) Jupiter (b) Mercury (c) Saturn
THEORY
Attempt questions 3(a), 3(b), and 4(b) on page 21 of Essential Geography.