Question 1:
From the standard BS AU 209-4a: 1995 Vehicle security - Part 4a: Specification for security glazing for passenger cars and car derived vehicles. Read through the standard, and then answer the questions below.
a. a.In your own words, give a brief description of what the standard covers; your answer should contain what is its aim and what type of materials it covers?
(You should aim to write no more than about 150 words in your answer.)
b. Give a brief explanation of the method used to assess the resistance of glazing material to removal by impact. Use your own words: do not copy from the Standard.
(Your answer should be fairly brief: aim to use no more than about 100 words.)
c. For the testing of a glazing material against BS AU 209-4a, a pendulum with a mass of 9.5 kg is used to impact the material. The pendulum is dropped from a vertical height of 700 mm. Calculate what impact speed is achieved with this configuration. (Hint: The speed of the pendulum is directly related to the drop in vertical height, similar to the free drop test you studied in Block 3 Part 2 with the drop weight test for safety glass oculars.)
Take the value of g, the acceleration due to gravity, to be 9.8 ms-2.
d. Explain in terms of energy conservation how, by knowing the vertical drop height, the energy at impact of a pendulum impactor can be calculated.
e. Calculate the impact energy for the impact configuration given in (c). Show your working fully. (Hint: Use 'Converting energy' which can be found in Natural Constraints at the end of Block 1 to help you here.)
Question 2:
This question carries 10% of the marks for this assignment.
a. Determine the homologous temperature of lead when it is operating at a temperature 150 °C? - use 327 as melting point i.e (327 +273 ) = 600K
b. When heated from room temperature at what temperature would a solder with a composition 80% by weight of tin:
i.begin to melt?
ii.become completely liquid?
c. Give two arguments against removing lead from electronic products.