a 50kg person is standing still in ice skates throws their 2.0kg helmet to the right at 25m/s while on a friction less surface.
1 answer:
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Complete Question
Martin is conducting an experiment. His first test gives him a yield of 5.2 grams. His second test gives him a yield of 1.3 grams. His third test gives him a yield of 8.5 grams. On average, his yield is 5.0 grams, which is close to the known yield of 5.1 grams of substance. Which of the following are true?
A His results are accurate but not precise.
B His results are neither accurate nor precise.
C His results are both accurate and precise
D His results are precise but not accurate.
Answer:
Correct option is A
Explanation:
From the question we are told that
The yield of the first test
The yield of the second is
The third yield is
The average yield
The know yield is
From the data given we see that
Since his average yield is closer to the known yield then the answer is accurate
But since the yield for each test are not repeated the answer is not precise
So the answer is accurate but not precise
Answer:
A (samolot) - 200 MJ = 200000000 J
B (dźwig) - 800 kJ = 800000 J
C (podnośnik)-1.6 kJ = 1600 J
Explanation:
Całą część pytania można znaleźć na poniższym schemacie.
Z diagramu załączonego poniżej; mamy
A - samolot lotniczy
B - dźwig
C - podnoszenie ciężarów
Wszyscy to wiemy ;
1kJ = 1000 J
1MJ = 1000000 J
Mamy cztery opcje; i.e 200 MJ, 800 kJ, 1.6 kJ and 250 mJ
Z czterech opcji można wykluczyć 250 mJ, ponieważ jest to 0,25 J, co przedstawia bardzo niską energię w porównaniu z trzema warunkami pokazanymi na schemacie.
Więc:
A (samolot) - 200 MJ = 200000000 J
B (dźwig) - 800 kJ = 800000 J
C (podnośnik)-1.6 kJ = 1600 J
Największą pracę wykona samolot. Jest tak, ponieważ ma bardzo dużą masę i bardzo dużą prędkość. W związku z tym istnieje potrzeba wytworzenia ogromnej ilości ciepła i energii.
Z drugiej strony żuraw może podnieść ładunek o wiele większy i przewyższa ciężar ciężaru, więc praca wykonywana przez dźwig musi być zdecydowanie większa niż praca ciężarka.
