Sand and silt are both examples of granular materials, which are collections of separate particles and distinct particles, such as raw flour in a container or jellybeans in a jar.The most common forms of sand and silt are composed of tiny fragments of quartz.
Rip tides, also known as rip currents, are strong narrow currents that can pull swimmers out to sea. Some rip tides are so strong that they can drag swimmers away from shore before they realise what is happening. Swimmers should keep an eye out for rip tides while swimming in the sea at the beach. Rip tides can be identified by discoloured water, choppy waves and a foamy surface. They can be filled with debris. Swimmers are told to remember the âthree Rsâ if they become caught in a rip tide.
In fact, such currents are more accurately described as longshore drift or longshore current (the defining characteristic of a rip current is that it goes out to sea). While rip currents are localised, longshore drift is general, moving in the same direction along a whole coastline. This poses little danger in itself, but can drag surfers towards hazardous obstacles (rocks, groynes, piers, etc.) without their noticing, or simply away from supervising family members and friends.