Answer:
1. Buy Quiet – select and purchase low-noise tools and machinery
2. Maintain tools and equipment routinely (such 3. as lubricate gears)
3. Reduce vibration where possible
4. Isolate the noise source in an insulated room or enclosure
5. Place a barrier between the noise source and the employee
6. Isolate the employee from the source in a room or booth (such as sound wall or window
Explanation:
Hope my answer will help u.
Answer:
a. 2.08, b. 1110 kJ/min
Explanation:
The power consumption and the cooling rate of an air conditioner are given. The COP or Coefficient of Performance and the rate of heat rejection are to be determined. <u>Assume that the air conditioner operates steadily.</u>
a. The coefficient of performance of the air conditioner (refrigerator) is determined from its definition, which is
COP(r) = Q(L)/W(net in), where Q(L) is the rate of heat removed and W(net in) is the work done to remove said heat
COP(r) = (750 kJ/min/6 kW) x (1 kW/60kJ/min) = 2.08
The COP of this air conditioner is 2.08.
b. The rate of heat discharged to the outside air is determined from the energy balance.
Q(H) = Q(L) + W(net in)
Q(H) = 750 kJ/min + 6 x 60 kJ/min = 1110 kJ/min
The rate of heat transfer to the outside air is 1110 kJ for every minute.
Answer: c fine sand aggregate, portland cement,fine sand
Explanation:
Answer:
The annual operating cost of the refrigerator is $102.78.
Explanation:
Power consumed by the refrigerator = 247 W = 247/1000 = 0.247 kW
Daily operation of the refrigerator = 19 hours
Annual operation of the refrigerator = 365 × 19 = 6,935 hours
Annual energy consumed = 0.247 kW × 6,935 hours = 1712.945 kWh
1 kWh of electricity cost $0.06
1712.945 kWh will cost 1712.945 × $0.06 = $102.78
Annual operating cost = $102.78
Answer:
The entity relationship (ER) data model has existed for over 35 years. It is well suited to data modelling for use with databases because it is fairly abstract and is easy to discuss and explain. ER models are readily translated to relations. ER models, also called an ER schema, are represented by ER diagrams.
