Download Horse and Wagon

Name: _________________________
Class: _________________________
Date: _________________________
Farmer Jo helps hitch Rancher John to his wagon one day, then he
says, ok John, let’s go!
Rancher John: Do you remember back in high school, when we took physics?
Farmer Jo: Yes, I do. We were lab partners in that class.
Rancher John: Ah, yes! You do remember Newton’s Three Laws, of course?
Farmer Jo: Yes, I do! I remember :
1. Every object persists in its state of rest or uniform motion in a
straight line unless it is compelled to change that state by forces
impressed on it.
2. Force is equal to the change in momentum (mV) per change in
time. For a constant mass, force equals mass times acceleration.
F= m a
3. For every action there is an equal and opposite reaction.
Rancher John: So then you remember how Newton’s third Law says that every
action force has an equal and opposite reaction force?
Farmer Jo: Yes, I do, now let’s get this wagon rolling.
Rancher John: Newton’s third Law says that if I pull on the wagon, the wagon
exerts an equal and opposite force on me, Don’t you agree?
Farmer Jo: Yes… but….
Rancher John: If these two forces are equal and opposite, they will cancel, so
that the net force is zero, right?
Farmer Jo: Well I suppose...but…
Rancher John:The net force is always important. If the net force is zero, then
Newton’s first and second laws say that the acceleration of the wagon must be
zero.
Farmer Jo: Yes, I remember the laws very well, This physics discussion is great,
but let’s get going!
Rancher John: Well, that’s the whole point! If the wagon’s pull is always equal
and opposite of my pull, then the net force will always be zero, so the wagon can
never move! Since it is at rest, it must always remain at rest! Now let’s unhitch
since I have proven that Newton’s Laws say that it is impossible for a horse to
pull a wagon!
Farmer Jo has a problem…
There is lots of work to be done, help Farmer Jo win his argument with Rancher
John.
On a separate piece of
paper, write down your
proposal to solve Farmer
Jo’s problem. Try to
make your reasons as
scientific and reasonable
as possible. With your
answer, include the
reasoning and full
explanation of your
answer.