Answer: a) 1.05kW b) 3.78MJ c) 5.3 bars
Explanation :
A)
Conversions give 900 kcal as 900000 x 4.2 J/cal {4.2 J/cal is the standard factor}
= 3780kJ
And 1 hour = 3600s
Therefore, Power in watts = 3780/3600 = 1.05kW = 1050W
B)
At 15km/hour a 15km run takes 1 hour.
1 hour is 3600s and the runner burns 1050 joule per second.
Energy used in 1 hour = 3600 x 1050 J/s
= 3780000 J or 3.78MJ
C)
1 mile = 1.61km so 13.1 mile is 13.1 x 1.61 = 21.1km
15km needs 3.78 MJ of energy therefore 21.1km needs 3.78 x 21.1/15 = 5.32MJ =5320 kJ
Finally,
1 Milky Way = 240000 calories = 4.2 x 240000 J = 1008000J or 1008kJ
This means that the runner needs 5320/1008 = 5.3 bars
Answer:
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Answer:
A. Manufacturers rating capacity ↔ 3. Must be marked on all jacks; must not be exceeded
B. Block Used to lift and hold heavy loads, allow them for travel ↔ 1. Place the jack head against this
C. Level surface ↔ 4. Place this under the base of the jack when it's necessary to provide a firm foundation
D. Jack ↔ 2. Used to lift and hold heavy loads, allow them for travel
Explanation:
The manufacturers rating for a jack is labelled on all jacks and should be referenced to compare with the load to be lifted so as to ensure a safe and successful lifting.
In order to lift a load, such as a car, it is required to place the jack on a level surface to provide balance during the lifting task
The head of the jack is placed against the block for lifting heavy objects for proper performance