1. Lab Investigation – Force, Mass, and acceleration
First, a word about units
How do we measure a force?
Newtons  N = ?
1 N =

2. Lab Goals
Using the provided equipment, find and describe (with words and mathematically)…
The relationship between Force, Mass, and Acceleration
The relationship between Weight (in Newtons) and Mass
Each person will be turning in a lab paper and should have an answer written in their own words.

3. Questions - Discussion
The relationship between Force, Mass, and Acceleration
The relationship between Weight (in Newtons) and Mass

4. Force, Acceleration, and Mass
Post-Lab Questions
What happened to the acceleration as you applied a greater force?
What happened to the acceleration when you increased the mass?
When accelerating the objects at the same rate, which one required a greater force?

5. Newton’s Second Law
Slide 4-29

6. Newton’s Second Law
Rearranged…

7. Checking Understanding
An object, when pushed with a net force F, has an acceleration of 2 m/s2. Now twice the force is applied to an object that has four times the mass. Its acceleration will be
½ m/s2.
1 m/s2.
2 m/s2.
4 m/s2.
Answer: B
Slide 4-33

8. Answer
An object, when pushed with a net force F, has an acceleration of 2 m/s2. Now twice the force is applied to an object that has four times the mass. Its acceleration will be
½ m/s2.
1 m/s2.
2 m/s2.
4 m/s2.
Answer: B
Slide 4-34

9. Checking Understanding
A 40-car train travels along a straight track at 40 mph. A skier speeds up as she skis downhill. On which is the net force greater?
The train.
The skier.
The net force is the same on both.
There’s not enough information to tell.
Answer: B
Slide 4-35

10. Answer
A 40-car train travels along a straight track at 40 mph. A skier speeds up as she skis downhill. On which is the net force greater?
The train.
The skier.
The net force is the same on both.
There’s not enough information to tell.
Answer: B
Slide 4-36

11. Newton’s Third Law
Slide 4-32

12. Checking Understanding
10-year-old Sarah stands on a skateboard. Her older brother Jack starts pushing her backward and she starts speeding up. The force of Jack on Sarah is
greater than the force of Sarah on Jack.
equal to the force of Sarah on Jack.
less than the force of Sarah on Jack.
Answer: B
Slide 4-37

13. Answer
10-year-old Sarah stands on a skateboard. Her older brother Jack starts pushing her backward and she starts speeding up. The force of Jack on Sarah is
greater than the force of Sarah on Jack.
equal to the force of Sarah on Jack.
less than the force of Sarah on Jack.
Answer: B
Slide 4-38

14. Summary
Slide 4-39

15. Summary
Slide 4-40

16. Summary
Slide 4-41