Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions
Archimedes’s Principle is a law of physics that states that when an object is totally or partially immersed in a fluid, it experiences an upthrust equal to the weight of the fluid displaced. The principle is most frequently applied to the behaviour of objects in water, and helps to explain floating and sinking, and why objects seem lighter in water. It also applies to balloons.
The key word in the principle is “upthrust”, which refers to the force acting upward to reduce the apparent weight of the object when it is under water. If, for example, a metal block with a volume of 100 cm3 is dipped in water, it displaces an equal volume of water, which has a weight of approximately 1 N (3.5 oz). The block therefore seems to weigh about 1 N less.
An object will float if its average density is less than that of water. If it is totally submerged, the weight of the water it displaces (and hence the upthrust on it) is greater than its own weight, and it is forced upward and out of water, until the weight if water displaced by submerged part is exactly equal to the weight of the floating object. Thus a block of wood with a density six tenths that of water will float with six tenths of its volume under water, since at that point the weight of fluid displaced is the same as the blocks’s own weight. If a dense material is made into a suitable shape, it will float because of Archimedes’s principle. A ship floats, whereas a block of iron of the same mass sinks.
It is also because of Archimedes’s principle that ships float lower in the water when they are heavily loaded (more water must be displaced to give the necessary upthrust). In addition, they cannot be so heavily loaded if they are to sail in fresh water as they can if they are to sail in the sea, since fresh water is less dense than sea water, and so more water must be displaced to give the necessary upthrust. This means the ship is lower in the water, which can be dangerous in rough weather.
From “Archimedes’s Principle”, MicrosoftÒ Student 2008[DVD]. Microsoft Corporation, 2007.
What happens when something is immersed in a fluid?
A. It will be pushed further down with a force, equal to the weight of the fluid displaced.
B. It receives an upward force, equal to the weight of the fluid displaced
C. It receives a download force, equal to the weight of the fluid displaced
D. The fluid will expand the object and overflow to the floor
Đáp án B
It receives an upward force, equal to the weight of the fluid displaced: “Nó nhận một lực đẩy lên tương đương với trọng lượng của chất lỏng bị chiếm chỗ”.
Câu này thích hợp với câu hỏi: “Điều gì xảy ra khi một vật nào đó nổi lên trong một chất lỏng?”
Chúng ta có thể tìm thấy ý này trong câu đầu của đoạn một: “Archimedes’s Principle is a law of physics that states that when an object is totally or partially immersed in a fluid, it experiences an upthrust equal to the weight of the fluid displaced.”
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
I know you are upset about breaking up with Tom, but there are plenty more
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
I'll have to go to the funeral of Ms. Jane, a of mine
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is CLOSEST in meaning to each of the following questions.
David was narrowly defeated and blew his own chance of becoming a champion.
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
Matthew's hands were covered in oil because he his bike
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
I'm sorry you've decided not to go with us on the river trip, but you change your mind, there will still be enough room on the boat for you
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
We found some real at the market
Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges
- John: "I can't see the stage very well from here." - Jack: " "
Mark the letter A, B, G or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.
It gives out light, but not heat and so is safe to use near inflammable liquids
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
The at the football match cheered their team on.
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It was so foggy that the driver couldn't the traffic signs
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It's no good pretending; you've got to reality
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
___________________with my previous job, I would have won a higher promotion and I in this unfortunate position now
Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges
Peter: "I've been awarded a scholarship to study in America." ~ Kate: "Uh, really? "
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is CLOSEST in meaning to each of the following questions.
If you had stuck to what we originally agreed on, everything would have been fine.
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
Wood that has been specially treated is regular wood