Vem

Key takeaways

Vem belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Vem to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Vem from memory before moving on to harder problems.

Reference excerpt

The VEM (Acronym of Vale eletrônico Metropolitano, Electronic Metropolitan Ticket) is a Smart card system used in bus, train and metro of the metropolitan area of Recife, Brazil. The VEM cards operate by using contactless technology as they have an internal chip that communicates with the validator by RFID. Since 11 of June 2014, All credits in VEM card has a validity of 180 days. There are many types of the Vem Card: "Trabalhador" (worker) Green color: is the standard and most issued version, with more than million and half issued cards. This card complies with Brazilian "vale transporte" rules, meaning that the credit is paid by the company that the user works and can only be used by that user in their house to work ride and vice versa, being impossible use the same card twice in a same ride, also there is a daily use limit of 8 rides. The card credit is paid by companies using a web-based application and the card is recharged during its normal use in Buses or Metro after 48 hours the credit is paid by the company. The use and balance of this type of card can be checked using a web-based application. The card is printed with the user name and its CPF. the worker card can also carry "comum" credit type. "Comum" (common) Green color: This is the standard card for non-worker users. It can be obtained by free by any user, as no data of the user is printed on card, however, the first charge is fixed in R$25,00. It can be purchased/recharged only with cash at the VEM site located at Rua da Soledade 259, Boa vista without any fares or at any reseller by adding a convenience fare of 2,5% of the recharge (it is deducted of the charge). How those sellers act as a resellers, often them can not recharge the card because all their "stock of credit" were sold. There is no discount in fare by using this card, except in the case you use interchange train-buses or buses-buses in some very specific lines. How this card is not linked to any law or rule, you can use it how many times you want until the card have credit, also if the card is lost, is impossible to retrieve its credit, as it are not linked to any CPF. the worker card can carry "common" credit type, meaning that is not necessary to buy another card if you have a worked card, you just need to add funds to it. Since June 2014, with the opening of BRT stations, the use of a VEM card is mandatory in the BRT system. The common card can be purchased in BRT Stations by R$4,00. "Estudante" (student) Yellow color: It is granted for almost any student whose school is located within Recife Metropolitan Area (only some exceptions apply) and it deducts only half of the fare. The card is printed with the photo of the user, and after its use, you need to show your student ID card to have your access authorized. In future, the fingerprint will be needed to be presented to certify that is the user that are using the card. To obtain and recharge it, riders need to get a student card and some documents of your school proof of student status. This card can not be used in special services like air conditioned buses, and have a daily limit of 8 uses and a monthly limit of 60 rides. "Rodoviário" (Bus driver) white color: used by bus drivers and fare collector to operate the system and to obtain free ride. the card has the worker photo and can only be used by them, in future, fingerprint will be needed during its use for free rides. "Infantil" (for children) fully colored with drawings: for children under six who cannot go through the turnstiles. "Livre Acesso": Blue or Orange color: This card grants access by free in public transport for people with some disability. The blue version is for people that not need a helper to travel, the orange is for who need the helper, granting the free ride for them, too. This card has the user photo printed and can only be used by its user. In future, fingerprint will be needed to be presented. Due Brazilian law, There are no limits for using those cards. "Idoso" (elderly) Red color: Still Not Released. "Vem Jaboatão": The city of Jaboatão dos Guararapes are not part of Grande Recife transport consortium, so it can not use the metropolitan VEM in its municipal micro-buses, so a new VEM needed to be created. It is not compatible with the metropolitan version.

Worked examples

Example 1 — a first encounter with Vem

Start with the simplest possible case. Write down what Vem claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Vem before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Vem ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Vem

In research: Vem appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Vem in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Vem is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fare collection systems, Smart cards, Transport in Pernambuco, so understanding it makes those chapters shorter.
In everyday life: Look for Vem outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Vem in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Vem means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Vem out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Vem in simple terms?

The VEM (Acronym of Vale eletrônico Metropolitano, Electronic Metropolitan Ticket) is a Smart card system used in bus, train and metro of the metropolitan area of Recife, Brazil. The VEM cards operate by using contactless technology as they have an internal chip that communicates with the validator…

Why does Vem matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Vem?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Vem.