January 29, 2021
Ashley Betz
PHY2048L-013
Experiment 2 Acceleration due to gravity
Purpose of Experiment
The purpose of experiment 2 was to measure
... [Show More] the acceleration due to gravity on two different
sized steel balls, assuming that air resistance is negligible. This is accomplished using a timing
pad.
Theory Summary
If an object is dropped it falls to the earth, but why? Isaac Newton created a formula for the
This study resource wa
s
shared via CourseHero.com
Law of Gravitation which describes the attraction between objects with mass. His formula shows
that objects of larger mass exert a much greater gravitational force than objects of smaller mass.
Hence, we can observe the force exerted upon us by Earth (gravity) while we cannot observe this
force between normal, everyday objects.
Newton’s Law of Gravitation, when calculated, results in a force (the force of gravity).
The Law of Gravitation is Fg=G(m1m2
/r2
) where G is the gravitational constant, m1 and m2 are
the masses of two objects, and r is the distance between the centers of the objects. Using the
equation F = ma, where m is mass, a is acceleration, and F is the sum of the forces acting on an
object, we can solve for a: a = F/m. Mass as the denominator cancels out the greater force of
attraction due to the difference in mass, so acceleration due to gravity is the same in all instances
on earth and comes out to 9.8 m/s2
. On another planet this acceleration would be different but
also constant.
Free fall motion, where an object is dropped and air resistance is negligible, can be
expressed with the equation h = ½ gt2 where h is the distance the object falls, g is the
acceleration due to gravity, and time is the amount of time since the object was dropped. Using
this equation, we should be able to reliably predict how long it takes an object to fall from a
given height. We can also calculate how far an object will fall in a given time.
Experimentally, if we know the height an object falls and how long it takes to fall (such
as in this experiment), we can calculate the object’s acceleration due to gravity. This should
come out to about 9.8 m/s2
. [Show Less]