A group of athletes are trying to turn a large wheel and axle to move a stone. What can they do to move the wheel with less effort?
a. Decrease the radius of the wheel.
b. Decrease the radius of the axle.
c. Push on the wheel closer to the center of the wheel.
d. None of the above

Examples of simple machines include a lever and gears. These are unpowered mechanical devices that accomplish a task with only one movement. Simple machines are arranged to make complex machines such as bicycles or cars. Complex machines may be powered and work by doing multiple movements to accomplish a task.

Explanation: I think it’s C if it’s not I’ll give random give aways for points

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.