Question

Toilet paper is, in a manner of speaking, kind of like a rope. And on occasion ropes will break. Your task for this station is to make several measurements and determine the relationship between the length of a rope and the tension required to break it.

• Record the methods you use in your experimentation, all the work involved in making this determination, and discuss your results.

• Think about it: Fishing line is generally sold in spools, and varying thicknesses are rated with different values - you might find one rated at 4# (four pounds) and one at 20#. What do these ratings mean, and how might you expect to distinguish these two spools?

• Say a friend of yours was fishing for a Mackeral tuna to take a photo of (the fish typically weighs 17ish pounds) and you mistakenly brought a 10# line, how might you still succeed at pulling in and releasing the fish?

Answer 1

We do the following experiment
From a very high building we roll down toilet paper to find out the length at which it breaks under its own weight
The following is the table of observations

l0, 0g	l1 , 100g	l2, 200g	l3, 300g
--	6.8	5.2	4
--	6.4	5.4	5
--	6.6	5.23	4.5
--	7	5.6	4.6
Average	6.7	5.3575	4.525

we can see that the toilet paper does not break even when the full roll is unbundeled
this shows that the force required to break the toilet paper is more than its own weight
but the second column is the length of the toilet paper when it breaks when attached to 100 gram mass on the end, third colum shows 200 gram mass, and fourth column shows for 300 gram mass
we can see the lenght of the toilet paper when it breaks gets smaller as the mass tied to it increases
hecne we can say force required to break the toilet paper decreases as its length increases, and this can be explained as the hangign portion of rolling paper adds to hangign force and hence requires less force externally to break

Now,
consider fishin spools
Pound test, also known as line test, refers to the fishing line's strength in terms of pounds. This is defined as the most weight that a particular line can hold before breaking. For example, if a
fishing line is labelled as 20 lb test then this means that the fishing can hold up to 20 lbs without breaking.

So from the given data
#4 line can hold 4 lb before breaking, #20 can hold 20 lb and hence is stronger
if they are made of the same material, this means the #20 is thicker

If we got 10# line for 17 lb load, we still might be able to reelin the fish using this line, but one has to be careful
lines are made with factor of safety, which means the line is actuially able to hold more than 10lb
but, due to jerks and other motion, more impulse can travel to the line and break it
and also, fish weigh less in water
so, we can reel in fish using this line if we are careful and there arent many jerts and motion which causes sudden increase in tension of the line