The hardy-weinberg equation is an expression showing the frequencies of 100 percent of the alleles for a specific gene in a population. if biologists can show that either p or q is changing over a period of time, what is occurring in the population?

In the Hardy-Weinberg equation, which is:
p² + 2pq + q² = 1
The letter p represents the homozygous dominant genotype and the letter q represents the homozygous recessive genotype.
If the value of either p and q decrease, this means that there is more mixing and interbreeding between the population of species, resulting in deviation from homozygous genotypes. 
This mixing may arise from removed barriers or from selection pressures causing the organisms to move from their original habitats.

When the ball is rising up, it gains kinetic energy. when the ball reaches the very top, it will have all potential energy, until it falls back down and gains it kinetic energy. finally when you catch the ball or it falls back down, it would have gained its potential energy back.

Predator instincts is what causes it