The rule of mixtures is used for which of the following purposes related to composite materials (one best answer):
(a) calculating the proportions of each material to include in the composite material, (b) calculating the strength of a fiber-reinforced composite material,
(c) calculating the weighted average of the primary and secondary material properties?

(c) calculating the weighted average of the primary and secondary material properties

Explanation:

Composite materials are materials that are made of two or more materials that have vastly different properties. This results in the property of the composite material to be superior the properties of the individual components.

The rule of mixtures states that the composite's  weighted average of the property values of the components measures the property value. The weighting is done by comparing the components which are present in the composite.

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts