Answer:
0.6048 kg of coal
Explanation:
Mass energy input = mass energy output/efficiency
Mass energy output = 30 GJ/ton= 3×10^10 J/1000 kg = 3×10^7 J/kg
Efficiency = 30% = 0.3
Mass energy input = 3×10^7/0.3 = 1×10^8 J
Mass of coal to be burned = power×time/mass energy input
Power = 100 W
Time = 1 week = 604,800 s
Mass of coal to be burned = 100×604,800/1×10^8 = 0.6048 kg
Answer:
d=1.49×1011m
Explanation:
Velocity is defined as the rate of travel, and can be found using the distance formula.
velocity=distancetime
Rearranging this formula we can solve for distance given velocity and time of travel.
d=vt
We are given velocity and time, and so can solve for distance, but if we plug in the values given;
d=(3.00×108m/s)(8.3minutes)
We can see that the units do not match up. Since seconds are the SI unit for time, we will need to convert 8.3 minutes to seconds.
t=(8.3minutes)(60seconds/minute)=(498s)
Now our units work out and we can solve for distance.
= 15.85
There are a few ways to do this- unfortunately different fields are better at it than others! Medical research is generally pretty good, some other fields likewise very good, some not as much.
Basically, though, what they do is use standadisation- they agree on the terminology, units of data, statistical measures, and so forth, that will be used in that scientific field. As much as possible, every scientist in the field uses those standards so everyone working in the field should recognise it.
For instance, in clinical trials, there is very good agreement worldwide on what the different metrics we use are- e.g. in cancer research, we usually want to know the 5-year survival rate (meaning the percentage of patients still alive 5 years after diagnosis). So anyone with the right training should be able to pick up a clinical trial report and understand what the results are and what the report is saying.
Answer:
Semantic memory is a category of long-term memory that involves the recollection of ideas, concepts and facts commonly regarded as general knowledge. Examples of semantic memory include factual information such as grammar and algebra.
