Form 2 Chapter 9

Form 2 ScienceChapter 9

FORM TWO CHAPTER 9STABILITY

1 Diagram 1.1 shows three wooden blocks labelled as A, B and C which are placed on a smooth board. One side of the block is lifted slowly to find out which block falls easily.

(a) Which object is the most stable?

……………………………………………………………………………………………………..

[1 mark]

(b) Which object is the most unstable?

……………………………………………………………………………………………………..

[1 mark]

(c) Arrange the blocks in an ascending order of stability.

……………………………………………………………………………………………………….

[1 mark]

(d) Diagram 1.2 shows a wooden block.

JPN Pahang 2009 119

A B C

Diagram 1.1

Diagram 1.2


(i) Draw a diagram to show how you would place the wooden block to make it more stable.

[1 mark]

(ii) What are the factors that influence the stability of the wooden block?

(a) ……………………………………………………………………………………………

(b) ……………………………………………………………………………………………

[2 marks]

JPN Pahang 2009 120


2. Model A, B and C in Diagram 2.1 have the same height.

(a) (i) Which model is the most stable?

……………………………………………………………………………………………………

(ii) Give a reason for the answer in (a)(i).

.…………………………………………………………………………………………………...

[2 marks](b) (i) Which object is the least stable?

…………………………………………………………………………………………………..

(ii) Give a reason for the answer in (b)(i).

…………………………………………………………………………………………………….

[2 marks]

(c) Draw lines and mark G to show the point of equilibrium of the objects shown in Diagram 2.3

[2 marks]

JPN Pahang 2009 121

A B C

Diagram 2.1

Diagram 2.3


3. (a) Diagram 3.1 shows two vases of flowers, P and Q.

(i) Based on your observation in Diagram 3.1, state the difference in the stability of vase P and vase Q.

……………………………………………………………………………………………………

[1 mark]

(ii) What inference can be made based on Diagram 3.1?

……………………………………………………………………………………………………

[1 mark]

(iii) State one hypothesis based on your observation in Figure 8.1.

……………………………………………………………………………………………………

[1 mark]

JPN Pahang 2009 122

P Q

Diagram 3.1


(b) A student carries out an experiment to investigate the situation in Diagram 3.1. Diagram 3.2 shows the apparatus set-up for the experiment.

The student takes the following steps:

Step 1: A lump of plasticine is made into a shape of a cylinder to form a model.Step 2: Four sticks of equal size are fitted into the four corners of the model to form the

legs so that it can stand on the table.Step 3: A string is hooked to the model. The string then passes over a pulley fixed at the

edge of the table. A dish is tied to the end of the string.Step 4: Weights are added to the dish until the model topples.Step 5: The weight needed to topple the model is then recorded.Step 6: Steps 2 to 6 are repeated using sticks of different lengths.

(i)Record the weight needed to topple models P, Q and R in Table 3.3.

JPN Pahang 2009 123

Plasticine

Stick

Pulley

Weights

Diagram 3.2

Plasticine

Stick

Pulley

8 cm 50

10

Model P


Model P Q R

Length of straws(cm) 8 12 16

Weight needed to topple model (N)

Table 3.3[2 marks]

JPN Pahang 2009 124

Model R

Model Q

Plasticine

Stick

Pulley

16 cm10

5

Plasticine

Stick

Pulley

12 cm20

10


(ii) Using Table 3.3, draw a bar chart to show the weight needed to topple the different models.

[2 marks]

(c) State the relationship between the length of the sticks and the weight needed to topple the model.

……………………………………………………………………………………………………….

………………………………………………………………………………………………………

[1 mark](d) State the variables involved in this experiment.

Manipulated variable: ……………………………………………………….

Responding variable: ……………………………………………………….

Controlled variable: Size and shape of plasticine model

[2 marks]

JPN Pahang 2009 125

40

10

20

30

Wei

ght n

eed

ed

to to

ppl

e m

ode

l (N

)

Model

50

60

70


(e) Based on the graph, predict the weight needed to topple the model if the length of the stick is longer than 16 cm.

……………………………………………………………………………………………………

[1 mark]

(f) Based on the experiment, state the relationship between the position of the centre of gravity and the stability of an object.

………………………………………………………………………………………………………

………………………………………………………………………………………………………

[1 mark]

JPN Pahang 2009 126


4. Diagram 4.1 shows four tables, P, Q, R and S.

(a)(i) Which table is the most stable?

……………………………………………………………………………………………………

[1 mark]

(ii) Explain your answer in (a)(i).

……………………………………………………………………………………………………..

…………………………………………………………………………………………………….

[1 mark]

(b)(i) Which table is the least stable?

……………………………………………………………………………………………………

[1 mark]

(ii) Explain your answer in ( b)(i).

……………………………………………………………………………………………………..

…………………………………………………………………………………………………….

[1 mark]

(c) Arrange the tables according to their stability in descending order.

[2 marks]

JPN Pahang 2009 127

P R

Q S

Diagram 4.1


(d) Diagram 4.2 shows a racing car.

How is a racing car designed so that it will not fall over easily in a race? …………………………………………………………………………………………………………

…………………………………………………………………………………………………………

[2 marks]

JPN Pahang 2009 128

Diagram 4.2

Documents

Form 2 Chapter 9