Jen+Hughes+11-11

November 11, 2008


 * Objectives:**
 * pass papers back
 * Daily Question
 * Mass vs. Weight Discussion
 * Lab Discussion
 * Begin Homework

//Does a dieting person lose mass or weight?
 * Daily Question**

Answer: A dieting person loses mass. The loss of mass influences the objects weight. When the person is dieting they are losing matter from their body, thus they are losing mass. When there is less matter, there is less for gravity to push on. Thus, the weight of the person also decreases.//


 * Daily Question... part two..**

//Can a person ever lose weight bur not mass?// Answer: Yes. A change in gravity can change a persons weight but not change their mass. By going somewhere were there is a greater or lesser gravitational force, the person is not losing matter (mass) but the gravitational force is influencint (increasing or decreasing) their weight. So, if a person were to travel to outter space where their is no gravity, or to a different planet where the gravitational force is different than here on earth, their mass would stay the same, but their weight would differ. The same applies if an individual were to travel to a higher altitude. Here, the person is technically farther away from the earth, so the gravity pulling on them is less. Being in water can also make this same change. When you are in water, there is more upward forces counteracting the downward force of gravity, influencing your weight and making you feel lighter (less weight).

FYI gravity on: moon= 1.6m/s^2 mars= 3.8 m/s^2 earth= 9.8 m/s^2

//What kind of scale would work anywhere in space? Both on earth and on moon or any other planet?//

A balanced scale such as the one pictured below would work anywhere., A digital scale would not work because these scales incorporates earths gravitational force to find the objects mass. If it was taken to another planet where the gravitational force is not the same, then it wouldn't calculate the correct mass. A balance scale such as the one pictured below would work because the gravity pushing down is the same on both sides, so it would calculate the correct mass.

To accurately answer this question, review over the worksheet handed out during class. It should be page 16 of the physics binder. This worksheet proficiently explains the difference between these two terms. They are completely different concepts and it will be importaant for every student to understand how they are different. They measure differnt characteristics of an object, thus they have different measurements and units. Mass will be measured in kilograms while weight is measured in Newtons. Notice both concepts are incorporating the metric system but are measureing different ideas. Mass measures the amount of matter that makes up an object. Therefore, it is measuring the number of protons, neutrons, and electrons because these make up matter which is what mass is measuring. Unlike mass, weight is measuring the gravitational force acting on the mass. The more matter there is, the more mass is measured, and the more there is for gravity to pull/ push on, and the more weight there is.
 * What is matter and what is mass??**

The homework sheet is page 17. Do this worksheet tonight and be prepared to discuss the answers in class tomorrow. The questions force the student to understnad and realize the difference between mass and weight. It also forces the individual to incorporate the equation weight= mass x acceleration.
 * Homework!!!!!**