Name :………………………… Chapter 1 - Scientific Investigation

Name :…………………………

Form:………………..

Chapter 1 - Scientific Investigation Q8. 1. Diagram 8.1 below shows an experiment is carried out to find the relationship between the length of a pendulum and the period of oscillations .

string retort stand pendulum

Diagram 8.1 a) State the hypothesis of the experiment ………………………………………………………………………….(1 mark) b) State the variables in the experiment. i. Manipulated variable:……………………………………………… ii. Responding variable : ……………………………………………… iii.Controlled variable : ………………………………………………

Length of pendulum(cm) Time taken for 1 oscillations (sec)

(3 marks)

20

40

60

80

100

1.2

1.4 1.6 Table 8.1

1.8

2.0

c Based on the data in the table 8.1 above, i) What is the length of the pendulum that has the fastest swing. ……………………………………………………………………………….( 1 mark ) ii) What is the length of the pendulum that has the slowest swing. ………………………………………………………………………………..(1 mark )

1

d( i) Based on the table above , plot a graph

Time (s)

2.0

1.8

1.6

1.4

1.2

0

20

40

60

80

Length of the pendulum (cm)

100 (2 mark)

2

(ii) If the length of the pendulum is 50cm ,predict the time taken to complete one oscillation. ……………………………………………………………………… …………..(1 mark )

P

R Q Diagram 8.1(b)

e. Diagram 8.1(b) above shows a pendulum swing from P to Q and back to P Define the meaning of one oscillation. ……………………………………………………………………………………..(1 mark) f. What is the conclusion of the experiment. …………………………………………………………………………………… ……………………………………………………………………………………….(2 mark) Q8. 2. A group of student carried out an experiment to study the relationship between the length of pendulum and the period of the pendulum swings. Diagram 8.2 shows the apparatus set up of the experiment. In this experiment, the pendulum of different length is used. The period for ten complete swings is recorded for the respective lengths of the pendulum.

string Retort stand Pendulum bob

Diagram 8.2

3

(a )

Record the period for then complete swings for the respective length of the pendulum in the spaces provided.

Length of pendulum = 10 cm Period for 10 complete swings = 10.0 seconds

Length of pendulum = 20 cm Period for 10 complete swings = …………………

seconds

Length of pendulum = 30 cm Period for 10 complete swings = ……………… seconds

4

Length of pendulum = 40 cm Period for 10 complete swings = ……………… seconds

Length of pendulum = 50 cm Period for 10 complete swings = ……………… seconds

( 2 marks ) ( b ) Complete Table 8.2 by recording the period for 10 complete swings. Then ,calculate the period for one complete swing. Length of the pendulum ( cm ) 10 20 30 40 50

Period for ten complete swing ( s ) 10.0

Period for one complete swing ( s ) 1.0

Table 8.2 ( 2 marks )

5

(c)

Based on Table 8.2, plot a graph for the period of one complete swing against the length of the pendulum.

d( i) Based on the table above , plot a graph Time (s)

5.0

4.0

3.0

2.0

1.0

0

10

20

30

40

Length of the pendulum (cm) d)

50 (2 mark)

Based on the graph, state the relationship between the length of the pendulum and the period of the pendulum swing. ………………………………………………………………………….. ( 1 mark )

6

(e)

State the variables involved in this experiment. Manipulated variable Responding variable Constant variable ( 3 marks)

( f ) Based on the graph ,predict the period for one complete swing if the pendulum with a length of 25 cm is used in the experiment. ……………………………………………………………………………… …. ( 1 mark ) ( g ) State the conclusion of the experiment. …………………………………………………………………………………………….. …………………………………………………………………………………………….. ( 1 mark ) Q8. 3.

Diagram 8.3 shows a scene at the playground. The three children on the swings are trying to solve a problem of who can swing faster. One child suggests that the length affects the time taken while another child thinks that it has to do with their mass.

Diagram 8.3 (a) Based on your observation in Diagram 8.1, state the difference in the time taken by the child in P, Q and R can swing fastest. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ( 1 mark )

7

(b) What inference can be made based on the Diagram 8.3? ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ( 1 mark ) (c) State one hypothesis based on your observation in Diagram 8.3. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ( 1 mark)

Diagram 8.4

Diagram 8.5

(d) Diagram 8.3 shows an activity planned to investigate how the length of a simple pendulum affects its swing. In Diagram 8.4, the pendulum bob is pulled to point A and released so that it swings to B and C. ( i ) How you want to consider it is a complete oscillation if the pendulum bob release form A.

A ( 1 mark ) (e) State the variables involved in this activity. Manipulated variable Responding variable Controlled variable

Mass of pendulum bob/angle of release ( 2 mark )

8

(f) Based on Diagram 8.4, record the readings of the stopwatch in Table 8.5.

( 2 marks )

9

(g) Based on Table 8.5, draw a graph of time taken or one swing against length of string.

Time for one oscillation (second)

Length of pendulum (cm) ( 2 mark ) (h) Predict the time taken for one swing when the length of the string is 20 cm. ……………………………………………………………………………….( 1 mark ) (i) Based on the graph, state the relationship between the length of the string and the time taken for one swing? ……………………………………………………………………………………………… …………………………………………………………………………………………….. ( 1 mark )

10