Sec 3 WB 7.1 Answer

Question (1)(a)
Strength of wind and fetch affect the size of waves.
The stronger the wind, the larger the size of the waves.
The longer the distance over which wind blows across open water, the larger the size of the waves.

Question (1)(b)
As the waves approach the shore, they will experience friction with the increasingly shallow sea bed. The waves lose energy and slow down.
However, the waves behind cause the waves infront to steepen.
When the waves become too steep, they will collapse and break to form a swash.
Gravity pulls the waves back into the sea, forming a backwash on the beach.

Question (2)
When waves reach the shore at an angle, the swash carries the sediments up onto the coast at the same angle. The backwash then carries the sediments back to the sea at a right angle to the coast due to the pull of gravity. This motion is repeated and gives rise to a zig-zag movement of sediments along the coast, known as the longshore drift.

Question (3)
The waves are acting mainly as an agent of deposition because the photograph shows small waves breaking on a genly sloping beach.