Magnets are able to place a force on certain materials. This force is called a magnetic force. The force a magnet exerts is a little different from the forces you may normally think about. You exert a force on a book when you lift it. You also exert a force on the pedals of your bicycle. In both those cases, those forces cause a change. The change you see in both these cases is called motion. Magnets, too, can produce change. They can produce motion just like you do. Unlike you, magnets do not have to touch something to exert a force. A magnetic force is exerted over a distance. Thats right, a magnet can push or pull certain items without ever touching them. Thats how the maglev train works. Do you know another type of force that does not require objects to touch? These forces are known as non-contact forces. Another type of non-contact force you may be familiar with is gravity. Gravity too can cause changes in motion. Gravity holds our moon in orbit without touching it.

Question: "What are non contact forces?"

Response: "Force exerted by touching"

A: no

Tropical climates are found around the equator. These climates have warm temperatures year round. Tropical climates may be very wet or wet and dry. Tropical wet climates occur at or very near the equator. They have high rainfall year round. Tropical rainforests grow in this type of climate. Tropical wet and dry climates also occur near the equator. They receive less rainfall. Most of the rain falls in a single season. The rest of the year is dry. Few trees can withstand the long dry season. The main plants are grasses. Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. Deserts can get less than 25 centimeters of rain per year. Thats less than 10 inches per year. How much rain do you get at your house?

Question: "What are two factors contributing to the dryness of deserts?"

Response: "They receive little rainfall"

A: yes

What if you could drain all of Earths oceans? What would it look like? You might be really surprised. You see that the surface has two main features. It has continents and ocean basins. Continents are large land areas. These are the areas that are mostly above sea level. Ocean basins extend from the edges of continents. They include the ocean floor and Earths deep ocean trenches. You will also notice the ocean floor is not flat. It too has many Continents are much older than ocean basins. Some rocks on the continents are billions of years old. Ocean basins may only be millions of years old. Because the continents are so old, a lot has happened to them! As we view the land around us, we see landforms. Landforms are physical features on Earths surface. These features change over time, but how? There are actually two types of forces at work.

Question: "What are large land masses called?"

Response: "Landforms"

A:
no