A net force of 15 N is applied to a cart with a mass of 2.1 kg. What is the acceleration of the cart? How long will it take the cart to travel 2.8 m, starting from rest?

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

What organs comprise the respiratory system of a bird

What goes in and out of a cell respiration?