Hello, I am having a difficult time getting far into solving thisproblem: \"A sm

Question

Hello,
I am having a difficult time getting far into solving thisproblem:

"A small piece of Styrofoam packing material is dropped from aheight of 2.00 m above the ground. Until it reaches terminal speed,the magnitude of its acceleration is given by a = g - bv. Afterfalling 0.500 m, the Styrofoam effectively reaches terminal speed,and then takes 5.00 s more to reach the ground. (a) What is thevalue of the constant b? (b) What is the acceleration at t = 0? (c)What is the accleration when the speed is 0.150 m/s?"

The first thing I did is to draw a free-body diagram of theStyrofoam falling, with the resisitive forces pointing upward, andthe weight pointing downward. Making downward being positive, theresistive forces are negative (hence the given accleration being a= g - bv).

To find b, I first need to find velocity and I don't see how Icould find that. I tried setting mg - bv = m(g -bv) = m(v^2/r).This seems kind of messy, but if it's necessary, I would thinkvelocity and mass would eventually cancel out. Is this the rightway of solving this problem?

I also thought about using a free-fall kinematic equation andsimply solving for velocity, but I think those are appropriate forproblems that neglect air resistance. Am I correct?

Explanation / Answer

The formula for finding velocity is V=d/t. So when calculate the velocity of the styrofoam it's velocity is .4m. I'm sorry but i don't believe your correct because a kinematic equation solves for problems not involving air restitance and the problem specifically states when the styrofoam reaches terminal speed. i probably didn't help much, but i hope it helps.

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