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Paul B

Guest

Need some Calc II Help =/

Ok so my professor gave us a bunch of review problems before our final, (including some topics we did not cover in class) and there a 2 that i have been trying to figure out/asking friends for help for days to no avail

1) A parachutist falling to earth is subject to two forces, her weight w=32 (m=her mass) and the drag on the parachute. Assume the drag on the parachute= 8|v|, that v(0)=0 and she weighs 128 pounds. Find formulas for velocity= v(t) and for the distance x= x(t) that she has fallen after t seconds.

ok so i know Force = F = 128-8v  and  F=ma= 4 dv/dt ....outside of this im completely lost

2) Power cables 10 yards apart form a catenary with length of cable 22 yards. Find the slope of the catenary where the cable meets the right-hand tower.

is this simply:
y=(a)cosh(x/a)
y`=22(1/22)sinh(x/a) = sinh(x/a)

m=sinh(b/a)
m=sinh(5/22)

or am i completely off here? Thanks in advance

Paul B

Guest

Re: Need some Calc II Help =/

That should read:

is this simply:
y= (a)cosh(x/a)
y`=22(1/22)sinh(x/a) = sinh(x/a)

m=sinh(b/a)
m=sinh(5/22)

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Need some Calc II Help =/

typo?, w is not 32: m=4 and w=128  since 4 tmz 32 = 128, where 32 = gravity in English.

Last edited by John E. Franklin (2008-05-06 12:14:48)

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igloo myrtilles fourmis

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Need some Calc II Help =/

falling linear.drag
See exponential equations...
http://hyperphysics.phy-astr.gsu.edu/hbase/lindrg.html#c3

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igloo myrtilles fourmis