Homework Help: Don't understand by the phrases 'retarding force'

1. Nov 20, 2004

Sanosuke Sagara

I have question to ask on retarding force and I just can't figure out the answer.

The question is in my attachment.

In the attachment,I didn't write out my solution because I totally blure with the question ask.

I hope that someone will help me by explain to me what the question want and some information on this question.I hope somebody will suggest me which website can I refer to but not solve the question for me.Thank you !

Attached Files:

• Doc1.doc
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2. Nov 20, 2004

vsage

Retarding force I believe is meant to mean force that "retards" the motion of the object (acts against it to slow it down). When rain is falling down, the question is saying there are two forces acting on the raindrop: gravity and its retarding force (given by the equation in your document). You will notice that the retarding force is proportional to v^2 so as you travel faster, the force that's trying to oppose your speed gets larger. At terminal velocity, the retarding force is such that it prohibits you from accelerating anymore (the sum of the forces = 0). I hope this all makes sense.

One last hint, instead of using the force of gravity = m*g, try using force of gravity = density * volume * g

Last edited by a moderator: Nov 20, 2004