4. The symmetric two-rod truss of Fig. 4 is subjected to a force P to the right at Point C. Each of the two identical rods has a cross sectional area of 100 cm², a moment of inertia of 50 cm⁴ for its section, and is made of elastic-perfectly plastic steel with a modulus of elasticity of 200 GPa and a yielding stress of 200 MPa. The length of Rods BC and DC are both 5 meters. (25%)
2) What is the maximum value of P? Why can't it be larger?
1) If P = 1000 kN, what is the displacement at Point C, including both the magnitude and direction?
3. Consider a cylindrical pressure vessel subjected to internal pressure p and an external axial force F. The vessel has an inner radius r and thickness t (r >> t). The magnitude of the external axial force F is 3πr²p. Three electrical resistance strain gages are placed on the outer surface of the vessel in the manner shown in Figures 3.1 and 3.2 to measure strains. Gages A, B and C measure the extensional strains εa, εb and εc in the directions of lines Oa, Ob and Oc, respectively. (25%)
2) If εb=3εc, find the value of Poisson's ratio v for the material of the vessel.
Questions 36~40 are based on the following reading.
"With the right policies in place, digital technology can give an unprecedented boost to sustainable development, particularly for the poorest countries," said UN Secretary-General António Guterres in a press release. "This calls for more connectivity; and less digital fragmentation. More bridges across digital divides; and fewer barriers. Greater autonomy for ordinary people; less abuse and disinformation." The 17th Internet Governance Forum, which kicked off on Monday and runs through Friday, is the first held in Ethiopia, Africa in 11 years. It puts a spotlight on the least connected region, with 60 percent of the population lacking Internet access.
Address the divide
Globally, more men use the Internet at 62 percent, compared with 57 percent of women. And in nearly all countries where data are available, rates of Internet use are higher for those with more education. Addressing these digital divides or "digital poverty" is at the top of the Internet has also paved the way for the proliferation of misinformation,disinformation and hate speech,the regular occurrence of data breaches,and an increase in cybercrimes.This year’s theme,”Resilient Internet for a Shared Sustainable and COmmon Future”,calls for collective actions and a shared responsibility to connect all people and safeguard human rights;avoid Internet fragmentation;govern data and protect privacy;enable safety,security and accountability;and address advanced digital technologies..
Internet boost for SDGs
"The Internet is the platform that will accelerate progress towards the Sustainable Development Goals (SDGs)." Our collective task here in Addis Ababa (the capital of Ethiopia) is to unleash the power and potential of a resilient Internet for our shared sustainable and common future," said Li Junhua, United Nations Under-Secretary-General for Economic and Social Affairs. In a video message to the Forum, released on Tuesday, the Secretary-General said: "We often hear that the future will be digital. But the future of digital must be human-centered."
Mr. Guterres highlighted that the Global Digital Compact he has proposed in anchored in human rights and aims to deliver on universal connectivity;a human-centered digital spare that protects free speech and privacy;and the safe and responsible use of data.He expects the Compact to be agreed by governments at the 2024 Summit of the Future - with input from technology companies,civil society,academia and others.
Retrieved and adapted from: https://news.un.org/en/story/2022/11/1131142,29th November 2022
40. What can be inferred from this passage? (A) The forum will gather the digital industry to solve digital poverty in Africa. (B) The UN will propose an agreement for promoting worldwide connectivity. (C) Every government in the world will be connected by signing the Global Digital Compact. (D) Future digital development will be based on the private high tech companies.
39. What does "Global Digital Compact" mean in the last paragraph? (A) A plan aiming to make the digital development condensed (B) An agreement of worldwide digital development (C) A contract for global internet access (D) A global project aiming to bargain with the high tech companies
38. According to the passage, what is the main aim of this year’s Internet Governance Forum? (A) To address internet crimes (B) To highlight the internet needs of the people around the world (C) To achieve the UN SDGs by using the internet (D) To solve the digital divide issue and provide a better cyber environment
This is a large modal.