Newton's Second and Third Law Problem!

[kevi555]

Hi there,

 

I was looking for any insight into the following problem:

 

Q: Jane wishes to quickly scale a slender vine to visit Tarzan in his treetop hut. The vine is known to safely support the combined mass of Tarzan, Jane and Cheeta. Tarzan has twice the mass of Jane, who is twice the mass of Cheeta. If the vine is 60.0m long, what minimum time should Jane allow for the climb?

 

Any help would be greatly appreciated,

 

K

[swansont]

Break the problem down:

 

What is the maximum force the vine can withstand?

 

If Jane is accelerating up the vine, what is the maximum acceleration she can have so that the force equals the max?

 

How does that acceleration translate into time?

[kevi555]

Yeah, but its tough because you dont really have much in the way of numbers to manipulate...I just need some help on how to get somewhere with it.. lol, Thanks.

 

K

[insane_alien]

think algebraicly, not numerically for this one.

[swansont]

The mass doesn't matter, so just pick a value (that satisfies the given relationships) if it will help. It has to cancel out at the end. But i_a is right, it's an exercise in algabraic manipulation, and in the long run you will be better served to be able to figure the problem out in those terms.

[YT2095]

assign valuse then if you want numbers, if we take cheetah a 1 then jane must be 2 therefore tarzan is 4.

 

1+2+4=7 that`s what the rope will take.

 

how many 2`s go into 7... 3.5

 

so right away you have a figure to work with.

 

 

that`s how I`de do it anyway!