Lab 8: Conservation of Energy
OBJECTIVE
The purpose of this experiment is to test the claim of whether or not the conservation of
energy can only be transferred, not created or destroyed, and to prove if it is true or false. To test
this claim, we will be using an elastic collision, and ensure that all the energy is being transferred
from one object to another.
THEORY
This test will be conducted by released a metal ball from a pre-specified height, and
allowing it to collide with a separate metal ball that is stationary on a stand, forcing the originally
stationary ball off the stand and onto the ground. To analyze the transfer of energy, the distance
that the stationary ball travels after the collision will be measured. For this experiment we have a
few assumptions that we are using. First we ignore air resistance. We also assume that the
collision between the ball and the pendulum is elastic. Therefore, the energy before the collision,
and after the collision are equal.
E(i) = E(f)
Total energy can further be broken up into potential energy U a nd kinetic energy T:
U(i) + T(i) = U(f) + T(f)
Since only the ball that is released from the magnet has gravitational potential energy, we use the
following equation with m being the mass of the ball, g being the acceleration due to gravity, and
h being the height of the pendulum ball in relation to the lowest point of the trajectory.
U(i) = mgh = T(f)
, There is no potential energy due to gravity after the collision since the energy was transferred to
the second stationary ball, giving us:
U(i) = mgh = ½ mv2 = T(f)
To find velocity: v = √2gh
To find L, the distance from the pendulum point to the point where the ball hits the ground we
use:
L = ½ gt2
To find t, t ime we use the following:
t = √2 L/G
The theoretical value of D can be found using:
D(theo) = vt = √2ght = √2gh x √2 L/G = √4Lh
Where h is found using:
l ( 1-cos𝜣)
Energy lost through collision is found using:
i)
⃤ E / E = mgh(i) - mgh(f) / mgh(i) = l ( (1-cos𝜣i) - (1-cos𝜣f)) / l (1 - cos𝜣
And for the double pendulum, to find energy lost through collision, the following equation can
be used:
( Cos𝜣(f) - cos𝜣(i) / 1 - cos𝜣(i) ) x 100%
PROCEDURE
For this experiment a pendulum apparatus is needed. As well as a stand for the stationary
ball to sit on, and a magnet to hold the ball that is attached to the pendulum in place before
releasing for the collision. To measure the distance that the stationary ball travels, a paper is
OBJECTIVE
The purpose of this experiment is to test the claim of whether or not the conservation of
energy can only be transferred, not created or destroyed, and to prove if it is true or false. To test
this claim, we will be using an elastic collision, and ensure that all the energy is being transferred
from one object to another.
THEORY
This test will be conducted by released a metal ball from a pre-specified height, and
allowing it to collide with a separate metal ball that is stationary on a stand, forcing the originally
stationary ball off the stand and onto the ground. To analyze the transfer of energy, the distance
that the stationary ball travels after the collision will be measured. For this experiment we have a
few assumptions that we are using. First we ignore air resistance. We also assume that the
collision between the ball and the pendulum is elastic. Therefore, the energy before the collision,
and after the collision are equal.
E(i) = E(f)
Total energy can further be broken up into potential energy U a nd kinetic energy T:
U(i) + T(i) = U(f) + T(f)
Since only the ball that is released from the magnet has gravitational potential energy, we use the
following equation with m being the mass of the ball, g being the acceleration due to gravity, and
h being the height of the pendulum ball in relation to the lowest point of the trajectory.
U(i) = mgh = T(f)
, There is no potential energy due to gravity after the collision since the energy was transferred to
the second stationary ball, giving us:
U(i) = mgh = ½ mv2 = T(f)
To find velocity: v = √2gh
To find L, the distance from the pendulum point to the point where the ball hits the ground we
use:
L = ½ gt2
To find t, t ime we use the following:
t = √2 L/G
The theoretical value of D can be found using:
D(theo) = vt = √2ght = √2gh x √2 L/G = √4Lh
Where h is found using:
l ( 1-cos𝜣)
Energy lost through collision is found using:
i)
⃤ E / E = mgh(i) - mgh(f) / mgh(i) = l ( (1-cos𝜣i) - (1-cos𝜣f)) / l (1 - cos𝜣
And for the double pendulum, to find energy lost through collision, the following equation can
be used:
( Cos𝜣(f) - cos𝜣(i) / 1 - cos𝜣(i) ) x 100%
PROCEDURE
For this experiment a pendulum apparatus is needed. As well as a stand for the stationary
ball to sit on, and a magnet to hold the ball that is attached to the pendulum in place before
releasing for the collision. To measure the distance that the stationary ball travels, a paper is
