Simple machines make work easier. most simple machines reduce the amount of effort force needed to move an object. this cart has a set of wheels. the wheels are actually simple machines: the wheel and axle. how can we change these wheels to decrease the amount of effort force needed to move the wagon?

a) use a larger wheel and axle.
b) make the radius of the axle larger in diameter.
c) make the radius of the wheel larger in diameter.
d) make the radius of the wheel smaller in diameter.

Iknow the answer is a but i don't know why

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

Which of the following describes a situation where competition between producers exists