1. when you drop a feather and a hammer the feather falls slower than the hammer
Potential energy is the "energy of position" - work done against a so-called "conservative force". Examples include a compressed spring, gravitational potential energy, chemical energy, nuclear energy.
By presence of other bodies with some mass.
The gravitational force between two objects depends on their distance, as well as the two masses involved. The value of the gravitational constant is 6.674 x 10^-11 (plus some units), in SI units. To get an actual force, multiply the two masses (in kilograms), divide by the square of the distance (in meters), and multiply that by the gravitational constant above. The answer is the force, in newton.
Resistance force is the force that an effort force must overcome to work on an object by way of a simple machine.
Some exmples of forces are- an object begining to move an object speeding up an object begining to slow down or stop moving an object changing direction an object remaining still
gravitational force of attraction/gravity -- force -- weight -- centripetal force, under some circumstances
Potential energy is when you do work against a conservative force. Examples are gravitational potential energy; the stored energy in a spring; chemical energy; and nuclear energy.
There are gravitational forces from the Sun, Moon and other planets. The Sun also exerts a force by means of the solar wind (charges particles that emanate from the sun and interact with the magnetic field and the upper atmosphere.
I assume you mean external forces? some examples include the force due to gravity, drag due to air resistance, someone pushing or pulling an object. Basically any force acting on the system that is independent of the system itself
External forces are when a force is between something outside and inside the system. Air resistance, cars moving on the road, friction, and gravity are examples of external forces.
A ball, an apple and hail
A rock on a hill
friction
gravity air resistance water resistance friction
Potential energy is the "energy of position" - work done against a so-called "conservative force". Examples include a compressed spring, gravitational potential energy, chemical energy, nuclear energy.
Some examples of contact forces are tension, friction, and air resistance. An example of a sentence using the term "contact force" is "The fundamental force that gives rise to contact forces is the electromagnetic force. "
By presence of other bodies with some mass.