Newton's Second Law
F = ma (Force = mass x acceleration)
Aim.
To investigate the relationship between force, mass and acceleration,
as detailed in Newton's Second Law.
Hypothesis.
For the experiment method we are doing, I predict that as the mass on
the end of the string increases, increasing the force, the trolley(s)
will accelerate faster.
I also think that the more trolleys there are, the more force will be
required to pull them along at the same speed as previous, and
therefore the acceleration at any given weight, compared to results at
a time when the were less trolleys, will be slower.
This makes sense to me because if the force (weights pulling the
trolley), mass (trolley(s)) and acceleration (of the trolley(s)) are
all proportional, which they must be according to the equation of
Newton's 2nd Law, then if one is increased, at least one or even both
of the others are, or the equation wouldn't work.
Method.
We put a trolley on a desk, attached via a piece of string to a mass
going off the end of the desk, on a pulley. The pulley itself was held
in place by a vice, and was secured very tightly so that it wouldn't
move during the experiment.
We measured a fixed distance, using a ruler, from the end of the
pulley (i.e. as far as the trolley could travel, towards the end of
the desk') to the trolley, and marked it out. The length of this
distance was decided on how long we could make the string, before the
weights would hit the floor as the trolley approached the end of the
table. This gave us the maximum length allowed us by the size of the
desk we were using, which turned out to be a not-very-long 70 cm.
We took note of the weights on the end of the string, held it next to
the top of the pulley, and then released the trolley, which was pulled
along by the weights.