(IME)

Conforme a figura acima, um corpo, cuja velocidade é nula no ponto A da superfície circular de raio R é atingido por um projétil, que se move verticalmente para cima, e fica alojado no corpo. Ambos passam a deslizar sem atrito na superfície circular, perdendo o contato com a superfície no ponto B. A seguir, passam a descrever uma trajetória no ar até atingirem o ponto C indicado na figura. Diante do exposto, a velocidade do projétil é:

Dados:

- massa do projétil: m

- massa do corpo: 9m

- aceleração da gravidade: g

(ENEM 2015 2º APLICAÇÃO) First Footing

One of the major Hogmanay customs was ‘’first-footing’’. Shortly after ‘’the bells’’ – the stroke of midnight when public clocks would chime to signal the start of the new year —, neighbours would visit one another’s houses to wish each other a good new year. This visiting was known as ‘’first-footing’’, and the luckiest first-foot into any  house was a tall, dark and handsome man — perhaps as a reward to the woman who traditionally had spent the previous day scrubbing her house (another Hogmanay ritual). Women or red heads, however, were always considered bad luck as first-foots.

First-foots brought symbolic gifts to ‘’handsel’’ the house: coal for the fire, to ensure that house would be warm and safe, and shortbread or black bun (a type of fruit cake) to symbolise that the household would never go hungry that year.

First-footing has faded in recent years, particularly with the growth of the major street celebrations in Edinburgh and Glasgow, although not the Scots love of a good party, of which there are plenty on the night!

Disponível em: www.visitscotland.com. Acesso em: 23 nov. 2011.

A partir da leitura do texto sobre a comemoração do Ano-novo na Escócia, observa-se que, com o tempo, aspectos da cultura de um povo podem ser:

    At Wednesday's shareholder meeting, a Google employee will step up to the microphone to argue that executive compensation should be tied to diversity goals.

   The push for a shareholder proposal opposed by parent company Alphabet marks a sharp escalation in the increasingly public disagreements between the Internet giant and some of its 80,000-plus staff.

    An employee revolt last week forced Google to back off a controversial and potentially lucrative military drone project. This week, employees are finding their voices again by joining shareholder groups to pressure Google to increase the racial, ethnic and gender diversity of its workforce.

    The activism is shaking up the Internet giant, which isn't used to being publicly challenged by its own employees.

   Liz Fong-Jones, a Google site reliability engineer, says she and a group of employees felt they had no choice but to take the unusual step of speaking out at the shareholder meeting after efforts to get management to address concerns proved unsuccessful. She hopes protest votes from concerned investors will motivate executives to make diversity a priority.

Disponível em: https://www.cbs19.tv. Acesso em: 03 fev. 2020 (FAF).

Os funcionários do mundo todo lutam por participação em decisões das empresas em que trabalham. No artigo acima, nos deparamos com uma interferência dos colaboradores da Google, que clamam por

(UDESC) A Revolução Sandinista em 1979 depôs o ditador Anastácio Somoza, que controlava o país há cerca de 40 anos. Essa revolução foi um dos episódios que marcou a instabilidade política dos países da América Central no processo de descolonização, facilitando a implantação de sangrentas ditaduras na região durante todo o século XX. O país onde ocorreu a Revolução Sandinista foi: 

 A figura descreve o gráfico de uma função exponencial do tipo y= a^x, de R em R.

Nessa função, o valor de y para x = - 0,5 é igual a