Spring Constant Lab made by Amanda Harris and Amra Beganovic, group 4A
Procedures
1. Attach spring to ringstand so
that it dangles vertically
downwards.
2. Measure the spring’s distance
from the table without any
weights on it.
3. Now attach weights in equal
increments to the spring with
tape.
4. Measure change in distance
for each weight and record
on table.
5. Begin from Setup in Step 1.
Set up motion-detector
directly beneath the spring in
order to measure highest velocity.
6. Attach weights to spring with tape and use LoggerPro to measure velocity (using
highest value).
Data Table
Starting Distance from Table (Original Distance): _______
Mass (kg)
Force (N) *
Potential Energy
Before* (J)
Distance from
table (m)
Potential Energy
After* (J)
Displacement
Velocity (m/s)
(distance – original=y)
Kinetic
Energy* (J)
Work done*
(J)
Spring Constant-k
(J) *
*Note: after completing experiment, you should have Mass, Distance from Table, and
Displacement columns filled out. You will fill out the rest during the questions.
Questions:
PART 1: SPRING EQUATION/HOOKE’S LAW
1. How many forces are working on the spring? What it is usually called? Calculate
its value and record onto table under Force.
Only one force is working on the spring and that is weight in the
downwards direction. It is calculated by m*g.
2. Hooke's Law states that: F=-ky. Calculate for k (using weight as F and y as
displacement) for all trials. Record onto table under Spring Constant.
3. Graph Force (weight) vs. Displacement (y). What does the slope of this graph
represent? What are the units?
The slope of the graph represents the spring constant. Its units would be
N/m.
PART 2: ELASTIC POTENTIAL ENERGY
4. Calculate the amount of potential energy within the system both before and after
the weight is added. Record onto table.
Should calculate using m*g*y for both values. The y-value should be
the original distance from the table to calculate for before and the changed
distance for the after.
5. Calculate how much Work was done (change in PE or KE) by the weights.
Record onto table.
Should calculate using formula Wnet=mg(yf -yi) or 1/2mvf2 –
1/2mvi2.
6.
Using the velocity found on LoggerPro, calculate the kinetic energy of the spring.
Record onto table.
Should calculate by setting up equation 1/2mv2. Should also be the
same with potential energy.
7. According to the Law of the Conservation of Energy is any energy lost when
potential energy is converted into kinetic energy? Explain why or why not and
relate to second data table.
No. There are no retarding or nonconservative forces involved. This is
why Work, KE and the difference between initial PE and final PE are (or
should be) all the same.
8. If no energy is lost, what happens when work (kinetic energy) is done by the
weight? Where would the potential energy come from?
From the spring’s potential energy, also called elastic potential energy.
9. Another way to calculate a spring's constant is using the Elastic Potential Energy
Equation, or elastic PE = ½*k*y2. Solve for k and record onto table.
10. How do your two spring constants compare? Should they be the same or
different? Explain.
The two spring constants should be very similar to each other, if not
identical. They both represent the same value, but were solved for by different
methods.