The of a sound wave is defined as the amount of energy passing through a unit area of the wave front in a unit of time.
a. intensity
b. compression
c. frequency
d. amplitude

Which factor contributed to the rise of african empires such as ghana and mali ? a. their creation and involvement in trade networks b. they focused only on agricultural production. c. they didn’t engage in warfare with other nations d. their geographic location protected them from attacks.