Answer:
C.
Explanation:
A person pushing a couch will face resistive force of friction . When resistive force is greater then his force of effort , couch will not move. This force is static friction because the couch is stationary. When the force of effort is increased , magnitude of static friction also increases keeping the couch stationary. The ability of the static friction to increase its magnitude is limited by a maximum value beyond which the couch starts moving. The static friction is then converted into kinetic friction.
In rest of the three cases object is already moving so kinetic friction is in action.
The correct answer is C. luster refers to how much light is in an object or how much reflects off. hope this helps, have an amazing day :)
Assuming it starts at rest, the roller coaster only has potential energy at the top of the hill, which is
When it reaches the bottom, its potential energy will have converted to kinetic energy,
where 
is its velocity at that point. By the law of conservation of energy, assuming no loss of energy due to other sources (e.g. sound, heat), we have
Both the butterfly and the large car will have equal forces but in opposite direction.
<h3>
Newton's third law of motion</h3>
Newton's third law of motion states that action and reaction are equal and opposite. That is, the force exerted on an object is equal to the reaction experienced by the object.
Fa = - Fb
where;
- Fa is the force exerted by the large car
- Fb is the force of the butterfly
Thus, both the butterfly and the large car will have equal forces but in opposite direction.
Learn more about Newton's third law of motion here: brainly.com/question/25998091
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