Newton's Second Law: Force and Acceleration (Part 3)

What You'll Learn

Newton's second law says that force equals mass times acceleration (F = ma). A heavier object needs more force to accelerate at the same rate as a lighter one.

Key Words

gravity
friction

Materials Needed

stopwatch
pencils
toy cars
ramps
string

Safety First

Work in a well-ventilated area when using vinegar or other strong-smelling substances.
Dispose of materials properly after the experiment.

Steps

Step 1 — Read

Look at the vocabulary words and write a definition for each in your own words.

Step 2 — Do

Test friction: pull a weighted box across 4 surfaces (carpet, tile, sandpaper, foil). Use a spring scale to measure the force needed for each.

Step 3 — Observe

Watch carefully for any changes and note the time.

Step 4 — Record

Create a data table to organize your measurements.

Check Your Understanding

Question 1

1 of 3

What unit is force measured in?