Which question asks for an opinion? A. Can people who visit Mars use the resources there to fuel a return
trip to Earth?
B. How much more radiation reaches Mars's surface than reaches
Earth's surface?
C. Is it a good idea to try to establish human colonies on Mars?
D. Is it possible to establish a human colony on Mars?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

The dot diagram represents the motion of the motorcycle as it moves from left to right

The electric potential v is constant everywhere within a certain region of space. which statement below is true? the choices are: the electric field is also constant (but not zero) within the region. a charged particle placed within the region will experience an electric force. the electric field is zero everywhere within the region. the electric field varies from place to place within the region.