Read the text and choose answers (прочитай текст и выбери ответы).

the discovery of gravity
(i) if i had a 1kg weight in one hand, and a 100g weight in the other hand, and dropped them at exactly the same time, which would fall the fastest … and therefore land first? the answer (which i hope you got right) is that they would both fall at the same speed (or, more specifically, with the same acceleration), and both would hit the ground at the same time. (ii) don’t worry if you got it wrong. even aristotle (who lived from 384 to 322 bc) believed that heavier objects fall faster than lighter objects, so you’re in good company! in fact, most people believed this until around 1638, when italian astronomer galileo galilei proved that objects fall at the same speed – whatever their weight (or, strictly speaking, their mass. [see this article to find out the (iii) the story goes that galileo proved his theory by dropping different-sized balls from the leaning tower of pisa. he found that the speed at which an object falls is determined not by how heavy it is, but by how long it has been falling. galileo increased our understanding of gravity, but even he couldn’t explain why it was that things fell to the ground in the first place. (iv) it was up to englishman isaac newton – arguably the greatest scientist who ever lived – to realise what gravity actually was. basically, if the mass of an object is doubled, the gravitational force is doubled, but the rate of acceleration remains the same. if the mass of an object is halved, then the gravitational force is halved, but again the rate of acceleration remains the same.

1. in para (i) choose the appropriate summaries of the paragraph idea:
mass of objects does not affect their falling acceleration speed
a acceleration speed of fallin object always depends on the object’s mass
large or small objects fall at different acceleration
when objects are falling their falling acceleration is the same despite their different weight
2. in para (ii) it is stated that:
galileo galilei and aristotle worked together on the issue of falling objects and their weight
aristotle discovered that objects fall at the same acceleration
galileo galilei discovered that objects fall at the same acceleration speed
all people before 1638 had already known that objects fall at the same speed

3.the summary of para (iii) is best described in russian as:
галилео галилей скидывал мячи разного размера с пизанской башни во имя своего эксперимента
галилео галилей, согласно легенде, скидывал разные по массе мячи с пизанской башни
галилео галилей проводил эксперименты из-за которых пизанская башня наклонилась
галилео галилей спускался на воздушных шарах с пизанской башни во имя своих экспериментов

4. according to para (iv) gravitational force increases along with increase of the mass of an object.
false
true

okotletacot    3   26.01.2020 14:45    1