Names: ______Block:______Date:____/____/______

Mass vs. Weight Exploration

Objective: By the end of the activity, student should be able to…

·  Understand the relationship between mass, weight, gravitational field strength (g), and gravity.

·  Use the correct units when describing mass, weight, gravitational field strength (g), or gravity.

·  Identify the relative range for the gravitational field strength (g) on different planets.

Activity I:

1.  Go to the following website and read about Mass vs. Weight: http://www.mathsisfun.com/measure/weight-mass.html

  1. Read through the webpage. Answer the following questions:
  2. List one specific condition where weight of an object might change: ______.
  3. What is the correct SI unit for measuring weight? ______.
  4. Go to the bottom of the page, click and answer questions in the “Your Turn” section. (See pic below)
  1. Answer questions 1-10 and mark down any notes/questions you have after reading the answers.
  1. Optional Challenge Option: Click on the link from the same webpage to read more about “Apparent Weight.” Answer the following questions about your apparent weight and use sketches, equations, diagrams, etc. to show how you arrived at your answer on a separate sheet of paper!

You are standing on top of a spring scale in an elevator. What is your apparent weight when the elevator is moving at

(a) constant speed upward?

(b) accelerating upward with a constant acceleration of 1.5 m/s2?

(c) accelerating downward with a constant acceleration of 1.5 m/s2?

Activity II:

1.  Go to the following website: http://www.mrmont.com/games/scale.html

  1. You should see a simulation that looks like this image:

  1. You will be collecting data using the simulation and the following procedure:
  1. Click on the 10g mass and put it on the spring scale to measure the weight.
  2. Record the mass (in Kg) and weight (in Newtons) on the data table.
  3. Repeat the steps for all the masses on the simulation.

Data Table:

Mass / Weight on Earth / Weight on Moon
0.05 kg

Analysis:

  1. Make a graph of weight vs. mass on graph paper. (Weight should be on the Y-axis, Mass on the X-axis). Be sure to properly title, label, plot the graph and draw a best-fit line.
  2. Repeat the experiment but change the acceleration to the moon. Plot the data for the moon on the same graph but use a different color or key.
  3. Explain the relationship between mass and weight of objects on Earth. What did you learn? Explain how this is different for the moon.
  1. Challenge Option: (On a separate sheet of paper)
  2. Determine the slopes for the two best-fit lines on the graph. (Don’t forget the correct units.) Show your calculation.
  3. Explain the significance of the slopes you just calculated.