How come places like Kansas has extreme temperatures in summer and winter

It's for homework and I can't ask my mom and dad because they are working late tonight pleasenhelp

Well, it's simple: Because the area is flat in terms of topography, there is little to block air masses from moving through. Terrain, especially mountains, water, and orientation to the general wind flow, all can limit the progression of air masses. Since the area has little to block the air from coming north from Mexico or the Gulf, or south from Canada in the winter, whatever is moving in tends to dominate.

because it's close to the rocky mountains which gives some cold temperatures but it's really because it has low elvation so it's weather is usually whatever air pressure system blows over it. And kansas is right in between the major air front directions from Mexico(warm air) and Canada(Cold air) so in the summer it's getting practically the same weather as mexico and in the winter the same weather as canada.

Kansas has a temperate climate, which means that summers are warm and winters are cold. If Kansas were on the equator, the temperature would be warm all year. Do you know why? It is because of the tilt of the earth, 23 1/2 degrees.
Another reason for extreme temperature in Kansas is that it is far from the ocean, which maintains a more constant temperature...because of thermal inertia... meaning that water holds its heat much longer than dirt and rocks.
OK?

They're away from the coastline, usually inland is always hotter or cooler than land closer to the ocean, as you've got less winds, humidity and varying temperatures.