English for Phisic

UNDERSTADING THE READINGDecide whether each of the following statements is true T, false F or with no information to clarify N Then make the necessary changes so that the false statement

Unit 2

PRACTICE &

PRACTICE AND HOMEWORK EXERCISES

WORKING WITH THE VOCABULARY FURTHER WORD

UNDERSTADING THE READING

Answer the following questions by referring to the reading

passage

1 What is a motion?

 Motion is typically and carefully described in terms of

distance, displacement, time, velocity, acceleration and

speed.

2 What do the Newton’s laws of motion state?

 If an object isn’t affected by any force or is affected whose resultant force is zero, a rest object will continue

to be stationary; a moving object will continue to move linearly and uniformly.

UNDERSTADING THE READING

Answer the following questions by referring to the reading

passage

3 What is gravitation?

 Gravitation, the attractive force between all objects that tend to pull them toward one another.

4 Who did the Copernicus system further develop?

 Johannes Kepler further develop Copernicus system.

UNDERSTADING THE READING

Answer the following questions by referring to the reading

passage

5 How do the Kepler’s laws state?

 1 The orbit of a planet is an ellipse with the Sun at one

of the two foci.

2 A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.

3 The square of the orbital period of a planet is

proportional to the cube of the semi-major axis of its

orbit.

UNDERSTADING THE READING

Answer the following questions by referring to the reading

7 What do Newton’s third law of motion require?

Newton’s third law of motion requires that the force a

planet exerts on the sun equal in magnitude to the force of the sun exerts on the same planet

UNDERSTADING THE READING

Decide whether each of the following statements is true (T), false (F) or with no information to clarify (N) Then make the necessary changes so that the false statements become true

T F N

1.In physics, acceleration is a change in position

of an object over time

2.Newton’s first law of motion is known as the law of inertia

3.Acceleration (the change of the energy, or velocity) of an object has the opposite direction with the force affecting the object, the magnitude

of the acceleration is directly proportional to the magnitude of force and inversely proportional to the mass of the object

UNDERSTADING THE READING

Decide whether each of the following statements is true (T), false (F) or with no information to clarify (N) Then make the necessary changes so that the false statements become true

6.Action and reaction are two opposite–acting forces

UNDERSTADING THE READING

Decide whether each of the following statements is true (T), false (F) or with no information to clarify (N) Then make the necessary changes so that the false statements become true

T F N

7 Mass is used to point out inertance of an object, any object having the lower inertance has the

lower mass and vice versa

8.Elastic force holds the objects on the surface of the earth

9.According to Newton’s hypothesis, this centripetal force is provided by the gravitational force exerted by the sun

UNDERSTADING THE READING

Decide whether each of the following statements is true (T), false (F) or with no information to clarify (N) Then make the necessary changes so that the false statements become true

T F N

10 Gravity is a particular of the gravitational force

UNDERSTADING THE READING

Word form

Emit  re-emit Arrange  re-arrange Construct  re-construct Radiate  re-radiate

Solve  re-solve Orient  re-orient

Please add the prefix re- to each word in the right column Then choose the correct word to complete each sentence

UNDERSTADING THE READING

Word form

Please add the prefix re- to each word in the right column Then choose the correct word to complete each sentence.

re-emit re-arrange re-construct e-radiate re-solve re-orient

a The atoms or molecules of the nonconductor …….… themselves so that their constituent electrons are as far as possible from the negatively charged body

b To… …….… … these conflicts Einstein developed an entirely new approach to the concept of gravity, based on the principle of equivalence

c These gases then … …….… … infrared radiation, some of which strikes and is absorbed by the earth

UNDERSTADING THE READING

Word form

Please add the prefix re- to each word in the right column Then choose the correct word to complete each sentence.

re-arrange re-construct re-radiate

d The No.1 and No.2 reactors, in fact, were returned to service

in November 1986 and the slightly damaged No.3 unit was … ……

… … in December 1987

e In this process, electrons in the molecules are set in vibration

by the electric fields of the light waves, and the vibrating electrons then … …….… …

f These signals are … …….… … when the brain processes them into an image that is right side up

WORKING WITH THE VOCABULARY

Complete each of the following statements with words/ phrases from the reading passage

Radius gravitation inversely spin speed inertia

Displacement stationary conservation velocity mass revolutio

1 Motion is typically and carefully described in terms of distance

… …….… … time, velocity, acceleration and speed

2 If an object isn’t affected by any force or is affected whose resultant force is zero, a rest object will continue to … …….… a moving object will continue to move linearly and uniformly

WORKING WITH THE VOCABULARY

Complete each of the following statements with words/ phrases from the reading passage

Radius gravitation inversely spin speed inertia

conservation velocity mass revolution

3 Acceleration (the change of the momentum, or velocity) of an

object has the same direction with the force affecting the object, the magnitude of the acceleration is directly proportional to the

magnitude of force and … …….… proportional to the mass of the object

4 Newton's third law also requires the … …….… of momentum, or the product of mass and velocity

WORKING WITH THE VOCABULARY

Complete each of the following statements with words/ phrases from the reading passage

radius gravitation spin speed inertia

velocity mass revolution

5 Without gravitation, the … …….… of the earth would send

them floating into space

6 Each planet moves so that ar … …….… vector from the sun to it swepts out equal areas in equal times

WORKING WITH THE VOCABULARY

Complete each of the following statements with words/ phrases from the reading passage

gravitation speed inertia

velocity mass revolution

7 Kepler’s third law indicated that how long it takes to make one complete … …….… (in relation to the size of the orbit)

8 Newton used Kepler’s third law to acheive at his law of universal

… …….…

WORKING WITH THE VOCABULARY

Choose the best word or phrase for each sentence

velocity

gravity orbit

inertiagravitational

internalbalanced

magnitude

additional

1 Kepler’s laws states that all planets move in elliptical

……… with the sun at one focus.

2……… is the property of all objects, which tends to

conserve the velocity in both the direction and magnitude

3.Mass has the……… property: when many objects are

put together into a body system, the mass of that system is total of mass of those object

orbit

inertia

additional

WORKING WITH THE VOCABULARY

Choose the best word or phrase for each sentence

velocity

gravity gravitational

internalbalanced

magnitude

4 Action and reaction forces are not ……… because

they act on two different objects

5 When two objects interact each other, they form a system The

interactive force between two objects is called ……… force.

6 The ……… force between any two particles is directly

proportional to the product of their two masses and inversely to the distance square between them

balanced

gravitational

WORKING WITH THE VOCABULARY

Choose the best word or phrase for each sentence

velocity

gravity magnitude

velocity

magnitude

FURTHER WORD

Multiple choice

1 Which sentence is right?

a The acceleration of a uniform accelerated linear motion

is always greater than the one of a uniform decelerated linear motion

b If a uniform accelerated linear motion has great acceleration, it has great velocity

c A uniform accelerated linear motion has the acceleration increasing or decreasing steadily over time

d The acceleration in a uniform accelerated linear motion has constant direction, dimension and magnitude

FURTHER WORD

Multiple choice

2 According to Keller third law, the time needed for a planet to

go around the sun

a depends on its mass

b depends on the average radius of its orbit

c depends on its speed of rotation

d is the same for all the planet

FURTHER WORD

Multiple choice

3 An object is moving with the velocity of 3m/s If suddenly forces acting on it disappear

a the object stops immediately

b the object changes the direction of motion

c the object slows down and stops

d the object continues to move in the former direction with the velocity 3m/s

FURTHER WORD

Multiple choice

4 A 0,5kg ball is lying at rest on the ground A football player is shooting the ball with a force of 250N The time that the foot acts on the ball is 0,02s The ball is flying with the speed of:

a 0,01 m/s b 0,1 m/s

c 2,5 m/s d 10 m/s

FURTHER WORD

Multiple choice

6 An astronaut is “weightless” in a spacecraft

a as it takes off from the earth

b in certain orbits only

c in all orbits

d only when the escape speed exceeds

FURTHER WORD

Multiple choice

7 The gravitational acceleration of an object

a has the same value everywhere in space

b has the same value everywhere on the earth’s surface

c varies somewhat over the earth’s surface

d is greater on the moon because of its smaller diameter

FURTHER WORD

Multiple choice

9 Action and reaction forces are:

a two balanced forces

b two contact forces

c two opposite–acting forces

d two elastic forces

FURTHER WORD

Multiple choice

10 A woman whose mass is 60 kg on the earth’s surface is in a spacecraft at a height of twice the earth’s radius (that is, 2 earth radii) above the earth’s surface Her mass there is

Translate into English

2 Trọng tâm của vật là điểm đặt của trọng lực của vật.

 The focus of the object is setpoint of object’s gravity

3 Khối lượng là đại lượng vô hướng, dương, không đổi đối với mỗi vật.

Mass is scalar quantity, positive, constant with the

objects.

Translate into English

FURTHER WORD

4 Gia tốc là đại lượng đặc trưng cho sự thay đổi vận tốc của một vật Nó được đo bằng sự nhanh hay chậm của chuyển động của một vật thể thay đổi theo thời gian.

 Acceleration is specify quantity for changing velocity

of an object It is measured by the increasing or decreasing of object’s motion changing overtime.

5 Trong tương tác giữa hai vật, một lực gọi là lực tác dụng còn lực kia gọi là phản lực.

 In the interaction between two objects, the one is called the action force another one is reaction force

2.3.3 Speak out loudly and state the meaning

of the following fomula

sqequal V zero (or V nought) t plus one halt at squared

V Vector equal the derivative of r vector

by t.

a vector equal minus of vectors V

Delta v vector over delta t.

FURTHER WORD

1 If the orbit of Mars is 1.52 times greater than the orbit of Earth, determine how much it takes Mars to complete one orbit?

FURTHER WORD

2 The moon is 3.84x108m from the Earth and circles the earth once every 27.3 days Compare the moon’s centripetal acceleration with the acceleration it would experience on the basis of Newton’s law gravitation

FURTHER WORD

3 Calculating the weight of an 75kg astronaut when he is:

a on the Earth (take g = 9,8 m/s2)

b on the Moon (take gm = 1,7 m/s2)

c on the Venus (take gv = 8,7 m/s2)

a.On the Earth: P = mg = 75 x 9,8 = 735 N

b On the Moon: Pm = mgm = 75 x 1,7 = 127,5 N c.On the Venus: Pv= mgv = 75 x 8,7 = 652,5 N