Leia o Texto 3 para responder a questão de número 29.
texto 3
New hydrogen-powered city car takes to the road
by Tom Simonite
http://www.newscientist.com/section/tech
[1] A concept car that attempts to sidestep the three main hurdles to the
dream of hydrogen-fuelled highways was unveiled in London, UK, today. Like
other hydrogen cars, the Riversimple Urban Car (RUC) is powered by a fuel cell
that combines hydrogen with oxygen from the air to release energy and nothing
[5] more toxic than water.
Its makers claim that by starting from scratch to build a small, efficient
car they can make it commercially viable more quickly than the major auto
manufacturers experimenting with adapting more conventional cars to hydrogen.
Honda predicts its FCX Clarity hydrogen car will enter mass production in 2018,
[10] but Riversimple is aiming to lease its first fleet in 2011 and mass produce in
2013.
Using hydrogen to power cars can cut urban pollution and carbon emissions too, if the hydrogen comes from a
renewable source or is used efficiently enough. The lack of fuelling infrastructure aside, the three main problems with
building a hydrogen car are that fuel cells contain expensive platinum, are difficult to make powerful enough to power a
[15] conventional vehicle, and the hydrogen they use is hard to store in large quantities.
The RUC is about the size of a Smart car, weighs 350 kilograms (772 pounds) and uses a relatively cheap 6
kilowatt fuel cell, compared to the more sophisticated 100 kW cell used by the FCX Clarity, he says. The fuel payload
need not be huge, either: just 1 kg (2.2 lb) of liquid hydrogen (26 litres at normal pressure) is enough to take the car 300
kilometres, says Spowers. The car’s top speed is 50 miles per hour (80.4672 kilometres per hour), and it can accelerate
[20] from 0 to 30 mph (48 km/h) in 5.5 seconds. Even using hydrogen derived from natural gas, its well-to-wheel carbon
emissions for urban driving are only 30 grams/km.
No trecho “Its makers claim that by starting from scratch to build a small, efficient car …” (linhas 06-07) , a locução “starting from scratch” indica que o RUC é um veículo
