A. COMING B. DERIVED C. DESCENDED D. EXTRACTED(76-80). READ THE PA...

75. a. coming

b. derived

c. descended

d. extracted

(76-80). Read the passage below carefully and choose the correct answer a, b, c or d.

DOWN-TO-EARTH IDEAS

If a big apple and a small one drop from an identical height at the same instant, which

one will reach the ground first? Neither! Without air resistance, a large apple will reach

the ground no sooner than a small one. Many people find this hard to believe, since it

seems to contradict “common sense”.

A great Italian mathematician and physicist named Galileo first proved that, without

friction, a heavy object and a light one released froni the same height will reach the

ground at the same instant.

He had begun to suspect that the common notion about heavier objects falling faster than

lighter ones was false when he experimented with pendulum. He found that a heavy

pendulum swung no faster than lighter one. Galileo went on to experiment with balls

rolling down a sloping plank, and proved that heavy balls reached the bottom no faster

than light balls.

Galileo’s investigation with the dynamics of motion revealed another important law of

physics: that, apart from air resistance, bodies accelerate constantly as they fall. In a

yacuum (where there is no air resistance) a heavy object does not fall faster than a light

one; the rate of acceleration (32 feet per second) is the same for all objects. Thus any

object travels faster at the end of its fall than at the beginning.

– air resistance (n): sức cản của không khí

– to contradict (v): mâu thuẫn với, trái với

– friction (n): sự ma sát

– pendulum (n): quả lắc đồng hồ

– dynamics (n): động lực học

– to accelerate (v): tăng tốc ->acceleration (n): gia tốc

– vacuum (n): khoảng chân không