Goal: In this activity you will learn to use a spring scale to measure forces in Newtons.

Transcription

1 Name: Block: Date: / / IP 6 Spring Lab Adapted from Minds on Physics: Inquiry Activity # &Concepts & Challenges:Physical Science Using a Spring, page Goal: In this activity you will learn to use a spring scale to measure forces in Newtons. For this activity, you will be using spring scales to measure forces. You will be using different spring scales, described in the chart below: description Range N (Green) N N N (Red) N N Basically, the Newton scale can only measure forces up to N, but the N scale can measure forces as large as N. Be CAREFUL! The N scale can only measure forces up to N; if you try to measure larger forces, the spring inside will be permanently stretched and the scale will be ruined! This is a picture of a spring scale similar to the ones you will be using. Make sure you use the right side of the scale for today s lab. Notice that there are two scales: The scale on the left has grams at the top we will not be using this side of the scales for today s lab. The scale on the right has Newtons at the top this is the side we will be using for today s lab! For most of today s lab, we will be using the spring scale to measure weights of objects. (An object s weight is a measure of the pull of gravity on the object.)

2 PROCEDURE:. Obtain the following: spring scales: a green N scale and a red N scale a set of hooked masses. Make sure that the pointer of the spring scale is at zero when nothing is hanging from it. The metal tab at the top may be used to adjust the scale.. To find the weight of an object: (a) Hold the spring scale in one hand and attach the object to the hook of the spring scale with the other hand (b) Carefully lower the object so that it does not abruptly drop if it seems as if the object will weigh more than the scale maximum, remove it from the hook and use a scale with a larger range (c) Observe where the pointer stops on the scale.. Use both your N (green) and N (red) scales to find the weight of several objects. (a) If an object weighs too much for the listed scale, place a large X through the box. (b) There are empty spaces in the chart. Find objects around the room to weigh. Be sure to write a description of the object in the Object column. Object N N g hooked mass (. kg) g hooked mass (. kg) g hooked mass (. kg) g hooked mass (. kg) g hooked mass ( kg) rock. Weigh a shoe.

3 (a) Weigh the shoe with one spring scale, as shown in the diagram below and record the value in the space to the right (include units) A GRAMS NEWTONS of A (b) Look at the diagram below which shows the same shoe being weighed by spring scales. First predict what each spring scale will measure, and then weigh the shoe as shown in the diagram and record the values (remember to include units). A B A B GRAMS NEWTONS GRAMS NEWTONS Predicted Measured

4 (c) Look at the diagram below which shows the same shoe being weighed by spring scales. First predict what each spring scale will measure, and then weigh the shoe as shown in the diagram and record the values (remember to include units). A GRAMS NEWTONS Predicted A B Measured GRAMS NEWTONS B ANALYSIS QUESTIONS: Answer the following questions using COMPLETE SENTENCES.. The rock does not have anything that can easily be attached to the hook on the spring scale. Describe the method you used to find the weight of this object:

5 . Observe any similarities/differences for the readings with the N and the N scale for the same object. (a) Are the values the same? Should they be the same? (b) Which reading do you think is better and why?. Where have you seen spring scales outside of school? What were they used for? You must give at least one example.. For the hanging masses, did you notice a relationship between the mass (in kilograms) and the weight you measured? Describe this relationship.

6 . Weighing a show: How did you your predictions for the spring scales compare to the actual readings in step b? Did the measurements surprise you? 6. Weighing a show: How did you your predictions for the spring scales compare to the actual readings in step c? Did the measurements surprise you?