What is an example of unbalanced forces

-- A tug o' war.  The whole football team is pulling one end, and two cheerleaders are pulling the other end.

-- A tractor-pull at a rodeo.  The tractor is pulling one way, and a bicycle is pulling the opposite way.

-- Two people pushing a car that's stuck in the snow.  One person is behind the car pushing it forward, and the other person is on the side of the car pushing it sideways.

-- A skydiver just jumped a few seconds ago, and he's falling.  The upward force of air resistance on him is less than the downward force of gravity, so the vertical forces acting on him are unbalanced, and he's accelerating downward.  As soon as the air resistance gets to be as strong as gravity, the two forces will be balanced.  He'll still keep falling, but he'll stop accelerating.

-- A TV satellite is in orbit.  The ONLY force on it is gravity.  Since there's no other force to cancel the force of gravity, the forces on the satellite are unbalanced, and it's accelerating.  The force of gravity on the satellite is always pointing toward the center of the Earth, so it's always accelerating toward the center of the Earth.

force tends to be low and long diustance masses are high

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).