Inference : Inertia depends on mass  

Hypothesis: The larger the mass, the larger the inertia 

Aim : To study the effect of mass on the inertia of an object

Manipulated: Mass, mResponding: Period of oscillation, TConstant: Stiffness of blade, distance of the centre of the plasticine from the clamp

Apparatus/Materials: Jigsaw blade, G-clamp, stopwatch, and plasticine mass 20 g, 40 g, 60 g, 80 g, and 100 g

Procedure:1. Measure the 20g of plasticine using an electronic balance.2. The jigsaw blade is clamped at the end of table with G-clamp.3. The jigsaw blade is put on plasticine (20g) at one end.4. The free end of the blade is displaced horizontally and released so that it oscillates. 5. The time for 10 complete oscillations is measured using a stopwatch. This step is repeated. 6. The average of 10 oscillations is calculated. Then, the period of oscillation is determined. 7. Repeat the experiment.

Graph of   T2 versus m: 

Hypothesis: When the force applied is constant, the acceleration of an object decreases when its mass increases.

Aim: To study the effect of mass of an object on its acceleration if the applied force is constant

Manipulated: Mass, mResponding: Acceleration, aConstant: Applied force, F

Apparatus/Materials: Ticker-timer, A.C. power supply, trolleys, elastic band, runway, wooden block, ticker tape, cellophane tape

Procedure:1. A ticker-tape is attached to the trolley and passed through the ticker-

timer.2. The ticker-timer is switched on and the trolley is pulled down the

inclined runway with an elastic band attached to the hind post of the trolley.

3. The elastic band must be stretched to a fix length that is maintained throughout the motion down the runway.

4. When the trolley reaches the end of the runway, the ticker-timer is switched off and the ticker tape is removed.

5. Starting from a clearly printed dot, the ticker tape is divided into strips with each strip containing 10 ticks.

6. A ticker tape chart is constructed, and from the chart, the acceleration of the trolley is calculated.

7. The experiment is repeated using 2 and 3 trolleys. 8. The elastic band must be stretched to the same fixed length as in

step 4.

Hoo Sze Yen Form 4 Experiments Physics SPM 2008

Results: M a ss o f Time of oscillations, t (s) Period of oscillation, T load, m (g) t1 t2 Average T = t/10 (s) T

2 (s

2)

20 40 60 80 100

Hypothesis: The bigger the weight, the longer the spring extension

Aim: To determine the relationship between the weight and the spring extension

Manipulated: Weight of the loadResponding: Spring extensionConstant: Spring constant

Apparatus and Materials: Spring, pin, weights, plasticize, retort stand, metre rule

Procedure:1. The length of the spring without any weights, l0 is measured using the metre rule with the pin as reference.2. A 50 g weight is hung from the bottom of the spring. The new length of the spring, l is measured. The spring extension is l – l0.3. repeated the experiment with weights 100 g, 150 g, 200 g, and 250 g.

Hypothesis: When the temperature of air increases, the volume increases if the mass and pressure is constant

Aim: To investigate the relationship between the volume and the temperature of gas

Manipulated: Air temperatureResponding: Air volumeConstant: Mass and pressure of the trapped air

Apparatus and Materials: Capillary tube, tall beaker, thermometer, Bunsen burner, tripod, wire gauze, retort stand, mercury or concentrated sulphuric acid, stirrer, ruler, ice, rubber band

Procedure:1. The air to be studied is trapped in a capillary tube by concentrated sulphuric acid.2. The capillary tube is fitted to a ruler using two rubber bands and the bottom end of the air column is ensured to match the zero marking on the ruler.3. Water and ice is poured into the beaker until the whole air column is submerged. Water is then stirred until the temperature rises to 10 °C. The length of the air column and the temperature of the water are recorded.4. Water is heated slowly while being stirred continuously. The length of the air column is recorded every 10 °C until the water temperature reaches 90 °C.

Hypothesis: The deeper the actual depth, the deeper the apparent depth

Aim: To study the relationship between the actual depth and apparent depth

Manipulated: Actual depth, DResponding: Apparent depth, dConstant: Refractive index of medium (water), n

Apparatus/Materials: Tall beaker, 2 pins, ruler, metre rule, retort stand

Procedure:1. A pin is mounted on a movable clamp on a retort stand.2. Another pin is placed at the base of the tall beaker. Water is filled as the actual depth to D = 7.0 cm.3. The object pin O is observed from the top, and pin I is adjusted vertically until it appears to meet pin O. At this point, the position of pin I matches the apparent depth, d of pin O. The apparent depth is measured from the top of the water level to the position of pin I. 4. repeated the experiment by changing the actual depth to 9.0 cm, 11.0 cm, 13.0 cm and 15.0 cm.5.The results are tabulated and a graph of D against d is plotted.

Hypothesis: The smaller the width of gap, the bigger the angle of diffraction of the wave.

Aim: To study the phenomenon of wave diffraction

Manipulated: Width sizeResponding: Diffraction patternConstant: Wavelength, frequency, and speed of incident waves

Apparatus/Materials: Ripple tank, reflector, stroboscope

Procedure: 1. Arrange two metal bar to produce a narrow gap.2. The motor is switched on to send plane water waves towards the

narrow gap.3. Observe the pattern before and after they pass through the narrow

gap using a stroboscope.4. Repeat the experiment with a bigger width of the gap.

Hypothesis: The refracted light ray obeys Snell’s Law which states that the value of sin i//sin r is a constant where i is the angle of incidence and r is the angle of refraction.

Aim: To study the relationship between the angle of incidence and angle of refraction

Manipulated: Angle of incidence, iResponding: Angle of refraction, rConstant: Plane mirror used

Apparatus/Materials: Ray box, glass block, paper, pencil

Procedure:1. The outline of the glass block is traced on a sheet of white paper and labeled.2. The glass block is removed. Point O is marked on one side of the glass block. With a protractor, lines forming angles of incidence 20°, 30°, 40°, 50° and 60° are drawn and marked.3. The glass block is replaced on its outline on the paper.4. A ray of light from the ray box is directed along 20° line. The ray emerging on the other side of the block is drawn.5. Repeat the experiment.6.The glass slab is removed. The points of incidence and the corresponding points of emergence are joined. The respective angles of refraction are measured with a protractor.7. The values of sin i, sin r, and sin i// Sin r are calculated.

Hypothesis: The refracted light ray obeys Snell’s Law which states that the value of constant where i is the angle of incidence and r is the angle of refraction

Aim: To study the relationship between the angle of incidence and angle of refraction Manipulated: Angle of incidence, iResponding: Angle of refraction, rConstant: Plane mirror used

Apparatus/Materials: Ray box, glass block, paper, pencil

Procedure:1. A straight line AOB is drawn on a piece of white paper.2. A line OC is drawn perpendicular to the line AOB.3. By using the protractor, draw angle of 30, 40, 50, 60 and 70 with the line OC.4. A plane mirror is placed vertically on the line AOB.5. A ray of light from the ray box is directed along 30° line. The ray emerging on the other side of the block is drawn.6. The angles of refraction are measured with a protractor.7. Repeat the experiment.

A O B

CRAY BOX

Hypothesis: The higher the current flowing through a conductor, the higher the potential difference

Aim: To determine the relationship between current and potential difference of a circuit

Manipulated: Current, I Responding: Potential difference, V Constant: Length of conductor

Apparatus/Materials:Two 1.5 V dry cells, battery holder, ammeter, voltmeter, constantan wire, rheostat, press-switch, connecting wire

Procedure:1. A constantan wire of 10cm length is connected across terminals X and Y .2. Switch on the circuit and adjust the rheostat until the ammeter reading is 0.2A. The voltage across the constantan wire is measured by voltmeter.3. Repeat the experiment by varying the value of I 0.3A, 0.4A, 0.5A, 0.6A.

4. Record the result.

Hypothesis: If the magnetic field is stronger, the force on the conductor carrying a current in the magnetic field will be stronger.

Manipulated: The number of magnet used Responding: The distance moved by sliding wireConstant: The size of current, the length of sliding wire

Apparatus/Material: C-shaped soft-iron core, 5 pair of flat magnets, bare copper wire, DC power supply, switch, metre rule, connecting wire

Procedure: 1. Switch on the circuit and adjust the rheostat until ammeter shows

reading, the current is 2A.2. Attach a pair of magnet on the C-shaped soft iron core. Switch on

the current and measure the distance x moved by the sliding copper wire.

3. Repeat the experiment with 2, 3, 4, and 5 pairs of flat magnet.

Hypothesis: The more the number of turn of solenoid, the larger the induced

Aim: To study the factor affecting the magnitude of the induced current.

Manipulated: number of turn of solenoid Responding: Induced currentConstant: number of magnets, speed of magnet falling

Apparatus/Materials:Flat permanent magnet, cardboard tube, sensitive centre-zero galvanometer, insulated copper wire, retort stand, metre rule

Procedure:1.Make a solenoid of 20 turns by winding round a cardboard tube.2.hold the permanent magnet at the height of 50 cm above the top end of the solenoid and then drop the magnet into the solenoid.3. record the deflection of the galvanometer as the induced current4. Repeat the experiment with different turns of wires on solenoid.

Hypothesis: The more the number of magnet used, the larger the induced current.

Aim: To study the factor affecting the magnitude of the induced current.

Manipulated: The number of magnet used Responding: Induced currentConstant: Speed of magnet falling, the number of turns of solenoid

Apparatus/Material: C-shaped soft-iron core, 5 pair of flat magnets, bare copper wire, DC power supply, switch, metre rule, connecting wire

Procedure: 1. Make a solenoid of 50 turns by winding a wire round a cardboard

tube.2. Drop a permanent magnet from a height of 50 cm above the top end

of solenoid .3. Observe and record the deflection of the galvanometer as the

induced current.4. Repeat the experiment with different number of magnet.