Lab 3 Practice

Conservation of Energy, from the OnRamps Lab 3 worksheet. Measure kinetic energy two ways, then decide whether they really differ. Every run gives new, realistic data.

Goal: measure kinetic energy directly from mass and velocity, and indirectly from potential energy using conservation of energy. At least three trials.

Q1Design the experiment

Pick a setup. On the real worksheet you write the materials, an annotated sketch, the procedure steps, the measurements and the analysis plan. Try writing yours before opening the sample.

Rubric check (each worth 10 points)

My design will give data that measure KE both directly and indirectly. My sketch shows every piece of equipment, where the detector sits and points, arrows for the motion, and labels. My steps are clear enough for another group to repeat without me. I listed every quantity I'll measure, with units, and how I'll turn them into KE.

Show a sample design for this setup

Q2Collect data and calculate KE

Cart mass

Release height

Measurements include realistic scatter, like real equipment. Keep the setup the same for every trial.

Fill in each KE in joules. A box turns green when you're within 2%. Use g = 9.80 m/s².

Run at least 3 trials to unlock the statistics rows.

Q3Uncertainty

mean = Σxᵢ / Ns = √[Σ(xᵢ − mean)² / (N − 1)]Δx = s / √N95% CI = mean ± 2Δx

Quantity	Direct KE (J)	Indirect KE (J)

Statistics checks allow 3%, since rounding adds up. Use your KE values from the table, as the worksheet does.

Q4Are the two KEs different?

Use the course's comparison rule. If either answer is "yes," you cannot say they're different. If both are "no," they are different.

1. Is the average direct KE inside the indirect KE's 95% CI?

2. Is the average indirect KE inside the direct KE's 95% CI?

3. So, are the two determinations of KE different?

4. If they differ, which is usually larger, and why?

Show the worked solution for this data

More practice: the Energy Quiz and the Energy Lab simulators.