Day 3:12-1-10 Pre-test

1
Day 312-1-10 Pre-test

• Topic Pre-test Newton
• Objective I will take the Pre-test learn what
  about a Newton.
• Science Starter Draw 2 forces on the shopping
  cart. Use the force symbol and direction arrow.

2
Copy these questions in your Notebook, then read
page 30 in the Textbook to find the answers

1. What is the common unit of force in the United
   States?
2. How is this unit (q. 1) abbreviated?
3. What is the unit of force that scientists prefer?
   
4. What is greater the pound or the Newton?
5. The pound is _______N?

3

• Units of Force-
• If you are mailing a package at the post
  office, how does the clerk know how much to
  charge you? The package is placed on a scale and
  you are charged based on the packages weight.
  For example, the scale shows that the package
  weighs 5 pounds. The pound is a unit of force
  commonly used in the United States. The pound
  measurement of force is based on the Roman unit
  libra, which means balance and is the source
  for pounds abbreviation, lb. The word pound
  comes from the Latin word pondus, which means
  weight. Although the pound is commonly used to
  express force, scientists prefer to use the
  newton. The newton (N) is the metric unit of
  force. A force of one newton is the exact amount
  of force needed to cause a mass of one kilogram
  to speed up by one meter per second each second
  (Figure 2.3). We call the unit of force the
  newton because force in the metric system is
  defined by Newtons laws. The newton is a smaller
  unit of force than the pound. One pound of force
  equals 4.448 newtons. How much would a 100-pound
  person weigh in newtons? Remember that 1 pound
  4.448 newtons. Therefore, a 100-pound person
  weighs 444.8 newtons.