1. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching 1. J.P. has been asked to design an experiment. Her assignment is to stretch an elastic band and to measure both the force on the band and the amount of stretch. DESIGN an experiment she could carry out. DRAW the apparatus here. DESCRIBE what she must measure.

2. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching 2. 10 20 30 40 50 cm 0 10 20 30 40 50 cm 0 Here is J.P.’s apparatus WRITE DOWN your readings for Force and Stretch. MARK on the diagram the stretch of the rubber band. 100 g DESCRIBE the easiest way to measure the stretch ?

3. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching 3. 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 In this experiment J.P. is squashing some plastic foam Height of foam in centimetres Compression of foam in centimetres Force in grams weight0200 515 0 TAKE READINGS and complete the table 100 g 10 5

4. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching 4. PLOT these values as a line graph. Here are some results from a squashing experiment Force in grammes weight Length in centimetres Squash in centimetres 100200300400 2521 0 191817,5 04677,5 Squash in Centimetres Force in grams weight 0200100300400 2 4 6 8 EXPLAIN how the information in the table or the graph tells you the foam becomes more difficult to squash the more you squash it.

5. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching 5. Here is a graph from a stretching experiment. A nylon thread and a metal wire of the same length and thickness were used. Extension in millimetres Force in gram weight 0 200400 600 800 1 2 3 4 DESCRIBE the behaviour of the materials in your own words. nylon thread metal wire

6. © KCL/PENTECH/WCED 2000 Day length Squeezing & stretching J.P.’s teacher has asked her to do a home assignment. She has to write an explanation of why some materials are more difficult to squash than others. Help J.P. out. WRITE your explanation here. 6.