To demonstrate the effect of slope angle and mass on a material's geomorphic threshold, you will perform the following experiment with four different types of materials (each of the materials are fixed to wooden blocks and will be used as a substitute for different types of rocks): Material A: sandpaper Material B: fabric Material C: aluminum foil Material D: paper 1. Hypothesize which of the four materials will have the greatest shear strength (cohesiveness or friction) and why. 2 marks Your answer: sanpaper has greatest shear strength because It 2. Hypothesize what will happen when you add more weight to the blocks. Will the materials fail sooner (lower slope angle) or later (greater slope angle)? Your answer: If we add more weight to the blocks, fail Scones. Instructor comment: 3. Using five trials for each of the following combinations, determine the average point at which the angle of repose is exceeded (slope failure) on a protractor. Put one block with the material face up at the top of the ramp and use a piece of string or tape to keep this bottom block stationary. Gently lay the second block on top of the first material, side- down, and then increase the slope angle until the block "fails". This is the measurement which you record. Conduct the experiment 5 times for each material and then calculate an average failure angle Material Trial 1 Trial 2 Trial 3 A: Sandpaper B: Fabric C: Aluminum Foil 31 D: Paper Instructor comment: 35 34' 32 28 35 31 31 Trial 4. 37 34 31 34 materials. Trial 5 32 30 29 34 Average 356 31 30.4 33.4 4. Add an extra block for additional mass to each trial and repeat the experiment. Use a small amount of tape around the edges to keep the top-most block stationary. Material Trial 1 Trial 4 A: Sandpaper B: Fabric C: Aluminum Foil D: Paper Instructor comment: 38 31 30" 34 Trial 2 Trial 3 40 31 31* 30 29 28 28 Trial 5 28 29 29 33 5. Examine the results from trials 1-2. Confirm or disprove your hypotheses from Questions 1 and 2. Your answer: Average 340 36.6" 21.8 30.6 P 29 29-6