Answer:
The average speed can be calculated as the quotient between the distance travelled and the time needed to travel that distance.
To go to the school, he travels 2.4 km in 0.6 hours, then here the average speed is:
s = (2.4km)/(0.6 hours) = 4 km/h
To return to his home, he travels 2.4km again, this time in only 0.4 hours, then here the average speed is:
s' = (2.4 km)/(0.4 hours) = 6 km/h.
Now, if we want the total average speed (of going and returning) we have that the total distance traveled is two times the distance between his home and school, and the total time is 0.6 hours plus 0.4 hours, then the average speed is:
S = (2*2.4 km)/(0.6 hours + 0.4 hours)
S = (4.8km)/(1 h) = 4.8 km/h
Answer:
D. The tea loses heat to the spoon causing the spoon to become warmer
Explanation:
When the silver spoon at a lower temperature than the tea, is added to the tea, it makes thermal contact. Hence, the heat transfer starts between the two until the equilibrium is reached. We know that the heat transfer takes place from the body with a higher temperature to a body with a lower temperature. As a result, the body with higher temperature loses heat and its temperature lowers down. While the body with a lower temperature gains heat and its temperature rises.
Therefore, the correct option is:
<u>D. The tea loses heat to the spoon causing the spoon to become warmer</u>
Fossil fuels have led to an increase in food costs.
Explanation:
Buried organic material over million of years form combustible geologic deposits of organic materials called fossil fuels that can be converted crude oil, natural gas, or coal.
Fossil fuel are currently used as a source of energy in machine and equipment applied in the farming industry. Mechanization has been made possible due to this type of fuel availability thus larger farms have been prepared for cultivation.In addition, other processes such as planting,weeding and harvesting are currently performed by farming machines which are propelled by fossil energy. So in general, fossil fuels in the farming industry has led to increase in amount of crop harvested because more farms are under cultivation and farming process is now mechanized. However, due to use of machines and energy, the production cost has increased, thus to cover for this increased cost, the prices for food products increases, making the cost of food commodities to rise.
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Fossil fuels: brainly.com/question/13660400
Keyword: Farming, industry, fossil fuel
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Data:
25 turn electromagnet
batter voltage: 1.5 V , 3.0 V , 4.5 V, 6.0V
paper clips picked up first try: 5, 12, 14, 20
paper clips picked up second try: 7, 12, 17, 26
average: 6, 12, 15.5, 23
50 turn electromagnet
battery voltage: 1.5 V, 3.0 V, 4.5 V, 6.0 V
paperclips picked up first try: 10, 28, 30, 44
paperclips picked up second try: 16, 24, 32, 50
average: 13, 26, 31, 47
