Английский язык. Ильичева Н.А - 4 стр.

UptoLike

ВУЗ: 

ВГУ | Воронеж

Составители: 

Рубрика: 

4
axis. The moon revolves around the Sun. The sun moves in the galaxy. The
galaxies move with respect to one another.
2
If an object changes its position (the location of an object), we say that
motion has occurred. When an objet is undergoing a continuous change in
position, we say the object is moving or is in its motion. We describe motion in
terms of distance and time. Two basic kinds of motion are straight line motion
and circular motion.
3
The terms speed and velocity are often used interchangeably. In physical
science, however, these terms have distinct meanings. The basic difference is
that one is a scalar quantity and the other one a vector quantity.
4
A scalar quantity is one that has magnitude or size only. For example, you
may be travelling in a car at 90 km/h. This figure is your speed. A vector
quantity, on the other hand, is one that has magnitude and direction. For
example, suppose you are travelling 90 km/h north. This quantity describes your
velocity.
5
The average speed of an object is the total distance travelled divided
by the time spent in travelling the total distance. In formula form we have:
distance travelled d
Speed = V =
time to travel distance t
6
When you drive down a straight highway and suddenly increase your
speed, you feel as though you are being forced back against the seat. When
driving fast on a circular cloverleaf, you feel forced to the outside of the circle.
These experiences result from changes in velocity (speed in a certain direction)
or, in other words, from acceleration.
7
There are three ways that you can change the velocity of an object. You
can (1) increase or (2) decrease its magnitude when travelling in a straight line,
or (3) you can change the direction of the velocity vector. When any of these
changes occur, we say that the object is accelerating. The faster the change in 
                                         4


axis. The moon revolves around the Sun. The sun moves in the galaxy. The
galaxies move with respect to one another.

2
       If an object changes its position (the location of an object), we say that
motion has occurred. When an objet is undergoing a continuous change in
position, we say the object is moving or is in its motion. We describe motion in
terms of distance and time. Two basic kinds of motion are straight line motion
and circular motion.

3
       The terms speed and velocity are often used interchangeably. In physical
science, however, these terms have distinct meanings. The basic difference is
that one is a scalar quantity and the other one a vector quantity.

4
      A scalar quantity is one that has magnitude or size only. For example, you
may be travelling in a car at 90 km/h. This figure is your speed. A vector
quantity, on the other hand, is one that has magnitude and direction. For
example, suppose you are travelling 90 km/h north. This quantity describes your
velocity.

5
      The average speed of an object is the total distance travelled divided
by the time spent in travelling the total distance. In formula form we have:

           distance travelled                       d
Speed =                                       V=
          time to travel distance                    t

6
       When you drive down a straight highway and suddenly increase your
speed, you feel as though you are being forced back against the seat. When
driving fast on a circular cloverleaf, you feel forced to the outside of the circle.
These experiences result from changes in velocity (speed in a certain direction)
or, in other words, from acceleration.

7
       There are three ways that you can change the velocity of an object. You
can (1) increase or (2) decrease its magnitude when travelling in a straight line,
or (3) you can change the direction of the velocity vector. When any of these
changes occur, we say that the object is accelerating. The faster the change in

Страницы