JAMB - Physics (1987 - No. 3)
A man walks 8km north and then 5km in a direction 60o east of north. Find the distance from his starting point
11.36km
12.36km
13.00km
14.36km
설명
R = \(\sqrt {5^2 + 8^2 - 2 \times 5 \times 8 \times cos 120^o}\)
R = \(\sqrt{129}\)
= 11.36km
R = \(\sqrt{129}\)
= 11.36km