Answer:
A-the energy of the wave decreases gradually
Explanation:
when a wave is acted upon by an external damping force the energy of the wave decreases gradually.
The energy degrades into the form of heat which is considered to be of less value and use. The reason is because it disperses and spreads more widely.
So therefore it end up as heat with a little sound but that is close to none because that too disperses into heat i.e. decreased form of energy.
<span>longitudinal waves
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Answer:
Explanation:
1. Frictional force is responsible for running of car and buses on roads.
2.Gravitational force exists between astronauts in space.
3. Magnetic for is responsible to attract the iron objects using a magnet
4.Electrostatic force is responsible for fiber to stick on the skin.This force occurs due to the presence of charge.
5.When a person is pushing a trolley then object experience a normal reaction from ground.
6.Gravitational force makes the planet to move in their orbits.
In a real system of levers, wheel or pulleys, the AMA (actual mechanical advantage) is less than the IMA (ideal mechanical advantage) because of the presence of friction.
In fact, the IMA and the AMA of a machine are defined as the ratio between the output force (the load) and the input force (the effort):

however, the difference is that the IMA does not take into account the presence of frictions, while the AMA does. As a result, the output force in the AMA is less than the output force in the IMA (because some energy is dissipated due to friction), and the AMA is less than the IMA.