物理 1986 年 DSE、CE 選擇題

1.

Ticker-tape with dots separated by 1 cm, 2 cm, 3 cm, 4 cm, 5 cm and 6 cm

The diagram above shows a ticker-tape produced by a trolley being pulled by a rubber band. Which of the following statements about the trolley is/are true ?

(1)Its displacement increases uniformly with time.

(2)Its velocity increases with time.

(3)Its acceleration increases uniformly with time.

2.

A body falls freely from rest. What are the distances travelled in the first and third second ?

	First second	Third second
	$4.9$ m	$14.7$ m
	$4.9$ m	$19.6$ m
	$4.9$ m	$24.5$ m
	$9.8$ m	$39.2$ m

3.

Which of the following motions of a given mass requires the greatest force $P$ ? (Assume that the surface is smooth.)

Four cases: A upward acceleration 0 on a 30 degree slope, B upward acceleration 1 m/s2 on 30 degrees, C acceleration 0 on 60 degrees, D acceleration 1 m/s2 on 60 degrees

4.

Which of the following is a vector quantity with correct unit ?

5.

Spring S attached to a wall and a 2 kg block on a table, string over two pulleys supporting a 6 kg block

The system of pulleys and blocks is at rest. What is the tension in string $S$ ? (Neglect all friction and the masses of the strings and pulleys.)

6.

Object O and inverted real image I on opposite sides, with points A, B, C and D on the axis

In the diagram shown, the image $I$ is produced by a lens. The object is placed at $O$ . What is the nature and position of this lens ?

7.

Which of the following ray diagrams correctly show(s) the paths of light rays through the lens ?

Three ray diagrams (1), (2), (3) for a convex lens with F and 2F marked

8.

If points $F$ and $F'$ represent the focal points of a concave lens, which of the following ray diagrams correctly shows the path of a light ray through the lens ?

Four ray diagrams A to D for a concave lens

9.

The heat capacity of an object depends on its

(1)material

(2)mass

(3)shape

10.

Syringe containing air connected by rubber tubing to a Bourdon gauge

In the experiment shown in the diagram, volume of the air inside the syringe is $25$ ml when the pressure is $1.0\times10^5$ N m $^{-2}$ . What is the volume of the air when the pressure is $0.5\times10^5$ N m $^{-2}$ ? (Assume that mass of the air in the syringe is constant.)