MST Three: The Force Gauge
Objectives:
Student will understand the use and application of a force gauge.
Student will understand how many aspects of baseball directly correlate with physical science.
Background:
Force is measured in newtons (N). Typically, we think of force as weight. We commonly measure the force of gravity in pounds (lbs.). The Newton is the metric version of weight. Although, the mass of the object is the amount of “stuff” or molecules in an object, the amount of mass would not change, but the weight of an object does. Consequently, in microgravity the amount of newtons of an object will be reduced as well.
Newton’s second law of motion describes force this way: Force=m x a. Where m is mass and a is acceleration. The unit of force is a newton only when the mass is measured in kilograms and acceleration due to gravity is 9.8 m/sec2. One could figure the force using the equation:
Force= m x a
Force= 1kg x 9.8 m/sec2 (Given a 1kg mass and the acceleration due to gravity)
Force= 9.8 N
So… if one took a 1kg mass it should be very close to 10 N (9.8 to be exact!!
Materials:
Force gauge
10 objects found in the class
Rubber bands
Procedure:
1. Read the directions on how to use the force gauge.
2. Complete the Self-Test.
3. Zero the force gauge and begin work
4. Measure the masses.
5. Record the results.
Questions:
1.Construct a chart with the data that was collected. The chart should have three columns. The first column would contain a description of the object, the second column, and the mass of the object, the third column the weight of the objects in newtons.
2. Graph the data using a two bar graphs. The horizontal axis of both graphs should be the name of the items abbreviated. The vertical axis of the first graph should be the mass in grams, the vertical axis of the second should be the weight in Newtons.
Directions in using the Force Gauge and Self-test
The force gauge can also be called a spring scale. There are usually two different type of markings on each scale, typically grams or kilograms and Newtons. Follow the directions below. Please quiz yourself on the correct usage of the force gauge.
Proper use of the force gauge:
1. DO NOT pull on the string.
2. Before you use the gauge it must be zeroed.
3. Adjust the screw or metal at the top of the gauge so that the zero mark is at the beginning of the scale.
4. If you unscrew the top all the way or keep playing with the gauge, it will break. Please be kind to it!
5. Attach items of your choice to the hook with rubber bands.
6. When you read the scale it must be at eye level. You need to look at the gauge straight on!
7. Make sure you identify the units (grams/kilograms/newtons) when you record your data.
Self-Test for the Force Gauge
Please write the correct answers to the following questions on a separate piece of paper using complete sentences.
1. Explain how to zero the gauge.
2. Name TWO things you should never do to the force gauge.
3. What are the units typically found on a force gauge?
Quick Questions on the Force Gauge
Please complete the following questions on a separate piece of paper.
1. One kilogram (kg) equals 9.8 newtons (N). REMEMBER: 1000 grams (g) equals 1 kilogram. Use the following formulas:
a. Number of kilograms x 9.8 = number of Newtons
b. Number of kilograms x 1000 = number of grams
c. Convert each of the following numbers to the units indicated:
i. 1 kg = 9.8N = ________g
ii. 2 kg = _______N = _________g
iii. 5 kg = _______N = _________g
iv. 0.5 kg =________N = _________g
v. 0.25 kg = _______N = _________g
2. Use the formula Force = mass x acceleration, (Newton’s Second Law of Motion) to solve the following problems.
a. What is the acceleration produced by a force of 12 newtons exerted on an object with a mass of 3 kg?
b. If there is a 10 kg mass and its acceleration is 9.8 m/sec2, what is the force produced?
c. To produce an acceleration of 4 m/sec2 on a bowling ball with a mass of 6 kg, what force would be required?
Independent Reading
Read the article, “The Most Difficult Act in All of Sports” (pp. 83-90) in Rainbows, Curve balls and Other Wonders of the Natural World Explained by Ira Flatow. Answer the following questions on a separate piece of paper using complete sentences.
Questions:
1. What are the two essentials for connecting the bat with a baseball?
2. According to the article, what is the time difference in getting a hit over second base or a foul near first or third base?
3. How could a person increase their bat speed?
4. Why do your hands “sting” sometimes after hitting a baseball?
5. What is one way to increase your hitting results?
6. Who now holds the record for the most homeruns hit in one major league season? What year was that record made?
Read the article. “Science at the Ball Game” (pp.247 – 258) in The Kids World Almanac of Baseball by Thomas G. Aylesworth. Answer the following questions on a separate piece of paper.
Questions:
1. What is inertia? Give an example.
2. What happens to acceleration as force increases? Decreases?
3. What is a baseball player doing when they allow their hand you “give” on impact when catching the ball?
4. What can a Baseball player do to make a throw go further?
5. What occurs as soon as the ball leaves the pitcher’s hand?
6. At what point does the ball start to drop after being released by a player?
7. Is a curve ball an optical illusion or real? How do we know this?
8. Is there a difference between a left handed and right handed curve ball? What is it?
9. How is a knuckle ball thrown?
10. After a knuckle ball has been released what actually happens to it as it is moving through the air?
11. What simple machine is used in baseball? What type of simple machine is it?
12. What is a fulcrum? Where is the fulcrum on a baseball bat?
13. What is the function of a lever?
14. Where is the force on a bat? Where is the load?
15. What 4 mechanical traits help a player hit a home run?
16. What did Breen determine as the most effective kind of swing?
17. How can a batter see the ball more clearly?
18. How can a batter bring around a bat the fastest?
19. Compare and contrast when a poor batter begins to swing as compared to a good hitter?
20. Compare how hitters use their center of gravity. Which way is better and why?
