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length of the plunger is 250 mm and its diameter 100 mm. There is a difference in
pressure of the water on the two ends of the plunger of 207.5 kN/m
importance of using electrical resistance glove
Most production processes generate defectives. However, the percentage of defectives will usually
be kept as low as possible. To check the production process, random samples or products are
usually drawn and tested.
Consider a certain mass-produced item. Suppose that the production process yields at most 2%
defectives, at least when the process is what is termed ‘under control’. To check the quality of the
production process, 400 of the items are randomly selected each hour. If at most 9 defectives are
detected, then it is concluded that the process is, still under control and nothing is done. But if 10 or
more defectives are found, then it is concluded that the production process is, in the terminology,
‘out of control’, and the process is stopped and investigated. Below, p denotes the proportion of
defectives in the large hourly production and bp denotes the (random) sample proportion of the
defectives in an hourly sample of size 400
A consumer organisation and the manufacturer of a certain brand of margarine are in dispute. The manufacturer states that his packs of margarine contain at least 250g of margarine whereas the consumer organisation claims that the content is at most 249g. A judge has to decide the issue.The judge decides to base her judgement on a random sample of ten packs of margarine.
The consumer organisation will be adjudged to be right if the random sample has a mean weight of less than 249:5g.
The manufacturer will be adjudged to be right if this mean weight is at least 249:5g.
The starting point for the judge is that he assumes a normal distribution with mean and variance 4, that is (u; 4) to be a good model for the weight X of a pack of margarine of that brand. Below, X denotes the mean weight (in grams) of the ten packs of margarine.
a)Determine the probability distribution of X
b)Calculate the probability that the judge decides (incorrectly) that the consumer organisation is right while the true u is equal to 251.
A belt pulley <b><i>system</i></b> uses a flat belt of cross section area 800mm squared and density <b><i>1200 kg</i></b>/m cubed. Angle of lap is 160 degrees on the smaller pulley. Coefficient of friction is 0.3. Maximum stress allowed in the belt is 3N/mm squared. Calculate; (i) Maximum power transmitted by varying speed. (ii) Speed at which it occurs. (iii The initial tension of the belt
rigid vessel. Heat is transferred to
the steam until a pressure of 600 kPa is reached.
3.2.1 Represent the process on a P – v diagram with respect to saturation lines. (4)
Determine:
3.2.2 The mass of the steam in the vessel, and (7)
3.2.3 The initial internal energy of the steam.
Mechanical systems highly depend on energy transfer. Piledrivers, Windmills are some commonly seen mechanical systems that depend on such a mechanism. Explain the effects of energy transfer of at least two such mechanical systems with uniform acceleration.
A steel thick cylinder of external diameter 150 mm has two strain gauges fixed
externally, one along the longitudinal axis and the other at right angles to read the hoop strain. The cylinder is subjected to an internal pressure of 75 MN/m2
and this causes the following strains:
(a) hoop gauge: 455 × 10-6 tensile.
(b) longitudinal gauge: 124 × 10-6 tensile.
Find the internal diameter of the cylinder assuming that Young’s modulus for steel is 208 GN/m2 and Poisson’s ratio is 0.283.
In an air standard Otto cycle the maximum and minimum tcmperatures arc 1400°C and 15°C. The heat supplied per kg of air is 800 kJ. Calculate the compression ratio and the thermal eficiency. Calculale also the. ratio of maximum to minimum pressures in the cycle.
#333702 on Dec 2022