B) A man is cutting down a tree with an axe. He hears the echo of the impact of the axe hitting the tree after 1.8 s.
i. What sort of obstacle could have caused the echo? [1]
ii. The speed of sound is 330 m/s. How far is the tree from the obstacle? [3]
c) Distinguish between the nature of sound waves in b and the water wave in a.

If steel is more dense that lake water, why can a boat float

What type of relationship exists between the length of a wire and the resistance, if all other factors remain the same? o a. resistance is directly related to length. ob. resistance is directly related to the square of the length. c. resistance is inversely related to the length. d. resistance is inversely related to the square of the length. reset next

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination. at the turning point, how far is the second student from the destination?