Research generally supports the theory that caffeine may enhance performance in long distance endurance events. which of the following is the least likely hypothesis?
(a) it may exert a psychologically stimulating effect.(b) it stimulates the release of epinephrine from the adrenal gland.(c) it decreases the use of both free fatty acids and muscle glycogen.(d) it may decrease the perception of effort during exercise.(e) it may exert a direct effect on the muscles to increase muscle contractile force.

(c) It decreases the use of both free fatty acids and muscle glycogen.

Explanation:

A hypothesis is a statement which includes a presumed explanation for a phenomena. It includes limited evidences. The statement is required to be tested by the experimental procedures.

C is the correct option as caffeine is a stimulant drug which increases muscular activity and improves the performance. The fatty acids and muscle glycogen both are used during the performance the caffeine has no influence over them.

answer: zinc is the substance which has a volume of 1.38 .

density is defined as the mass of an object per unit volume.

it can be calculated by dividing mass of a substance by its volume i.e.

si unit of density is kg per cubic meter and cgs unit of the same is gram per cubic centimeter.

now from the given data volume can be calculated by the formula .

hence, the volume of aluminium will be = which comes out to be 1.703 .

similarly, volume of zinc, chromium, and nickel will be 1.378 , 0.869 , and 0.356 respectively.