The second Examination of English

Gravity of earth If it wasn’t for the Earth’s gravity, we’d all float off into space. So don’t panic when I tell you that you’re constantly falling towards the Earth at an accelerating rate of 9.8 meters/second2. Fortunately, you’re also standing on the Earth, so that’s keeping you from falling.

Gravity comes from mass. The more mass an object has, the more gravity it will exert on objects around it. The amount of gravity that you experience falls off quickly over distance. So, the force of gravity that you feel on the surface of the Earth is much different from what you would experience at the distance of the Moon, or further. 9.8 m/s2 is the gravity close to the surface.You might be surprised to know that the force of gravity on Earth actually changes depending on where you’re standing on it. The first reason is because the Earth is rotating. This rotation is trying to spin you off into space, but don’t worry, this force isn’t much. The gravity of Earth at the equator is 9.789 m/s2, while the force of gravity at the poles is 9.832 m/s2. In other words, you weigh more at the poles than you do at the equator because of this centripetal force. Gravity also decreases with altitude, since you’re further away from the Earth’s center. The decrease in force from climbing to the top of a mountain is pretty minimal (0.28% less gravity at the top of Mount Everest), but if you’re up at the altitude of the International Space Station, you only experience 90% of the force of gravity you’d feel on the surface.

Finally, the force of gravity can change depending on what’s under the Earth beneath you. Higher concentrations of mass, like high density rocks can change the force of gravity that you feel; although, this amount is very slight.

From:Universe Today.com

1.Choose the best answer a,b or c to complete each statement: 1-The text is:

a)invitation. b)story. c)web article. 2-The text describes: a)mathematic’s theory. b)principle in physics. c)experiment in biology.

2.Say if these statements are (T) or (F) according to the text:
a)Earth’s gravity keeps us standing instead of floating off in space.
b)The amount of gravity is the same in earth as in the moon.
c)A person weighs heavier at the equator.
d)Concentrations of mass can change gravity considerably.

3.Answer these questions according to the text:
a)Explain the relation ship between gravity & mass?
b)What makes gravity changes from place to another one?.
c)How do we measure the force of gravity?(the unit)?


4.What or who do the underlined words refer to in the text:

a-I(§1). b-it(§2).

Text exploration:

1.Find in the text words that are opposite in meaning to:

a-raising‡……………… b-bottom‡……………….. c-low‡……………

2.Divide these words into roots & affixes:

rotation – force – international – unfortunately

prefix root suffix

3.Put the verbs in brackets in the correct form:
a-If unlike charges meet,they(to attract) each other.
b-You (to understand) better,if you take more exercises.
c-If I(to be) you,I would ask an expert about gravity.

4.Match the sentences in column (A )with their functions in column (B):

(A) (B)

1-If I were you,I would study English at university. a-regret.

2-If I had done my home work,I would have got better marks. b-blame.

3-If you had started earlier,you would havearrived at school on time. c-advice.


5.Mark the primary stress in the following words:

technology – rotation – scientific – sociological.


Written expression: Choose either:

Topic1/

Are you for or against technology advance…… In few lines,explain the advantages & disadvantages of technology in our society.

Or

Topic 2/
complete this conversation:

A:………………………………………………………………………………………………………………………………………? B:I think it was Isaak Newton. A:…………………………………………………………………………………………………………………………………… ? B:Yes it was by chance. A:……………………………………………………………………………………………………………………………… ? B:He was sitting in quite orchard & observed an apple falling to the ground. A:…………………………………………………………………………………………………………………………………… ?
B:The idea that flashed in his brain was that the same force that pulled the apple to the earth,also drew the moon towards the earth & held planets in their courses.

Good luck