5116 Prelim P2 Bbss 2009

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 Section A Answer all questions Write your answer in the spaces provided on the question paper 1.

beaker can hold 250cm3 of liquid. When it is filled with paraffin (density 0.80g/cm3), the total weight is 2.6N. Assume g= 10N/kg. (a) Calculate the mass of the filled beaker.

mass = _______________ [1]

(b) Calculate the mass of paraffin in the beaker. State clearly the formula used.

mass = _______________ [2]

(c) Calculate the weight of the beaker.

weight = _______________ [2]

2. A wide range of the electromagnetic spectrum is being used in the medical field. State which component is used in each of the following (a) Treating cancer _____________________ [1] (b) Radiography _____________________ [1] (c) Optical fibres _____________________ [1] 2

A

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 3. A motorcycle and a rider have a combined mass of 350 kg. During a trial run on a racetrack, the motorcycle accelerates uniformly from rest at a constant rate of 8.0m/s2 until the speed is 60 m/s. The motorcycle then travels at a constant speed until it has gone a further 600 m. It then comes to rest with a constant deceleration in a further 8.0 s. (a) On the grid provided below, plot a speed-time graph to show the motion of the motorcycle

[4] (b) Calculate the kinetic energy of the motorcycle and rider when they are travelling at constant speed.

kinetic energy = __________ J [2] (c) Calculate the braking force on the motorcycle during the final 8.0s of the journey.

braking force = __________ N [3]

3

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2

4.

(a) Speed is a scalar quantity. Velocity is a vector quantity. State the difference between a scalar quantity and a vector quantity _______________________________________________________ ______________________________________________________ [1] (b) The figure below shows two forces of magnitudes 6N and 8N acting on an object P. The forces are at right angles to each other. The diagram is not to scale. 6N

8N Fig. 2.1 On the space below, draw a vector diagram to determine the resultant force on object P. State the magnitude of the resultant force and show its direction on your vector diagram.

4

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 magnitude = __________ N [4] 5. The figure below shows a tool that helps disabled people to open ring-pull cans.

ring pull

(a) A force of 5.0 N is applied at the end of the tool as shown. Calculate the force F at the ring-pull

F=

__________ N [3]

(b) In the calculation in (a), the weight of the tool is ignored. Assuming the tool is made of the same material throughout, mark out the likely position of the center of gravity and label it cg. State and explain what impact, if any, will it have on the force required to open ring-pull cans. _____________________________________________________ _____________________________________________________ _____________________________________________________ ___________________________________________________ [3] 5

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2

6. Explain why solids have fixed shapes but liquids take the shape of their containers. In your answer you should include how the motion and separation of the molecules differs between the 2 states ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ________________________________________________________ [4]

7. The figure below shows three different cans A, B and C. Each can is filled with hot water at a temperature of 80°C .

Cans A and B are the same size; can C is smaller. Can A has a shiny silver surface. Can B has a different surface to can A. Can C has a similar surface to can B. (a) Can B radiates heat at a higher rate than can A. Suggest two reasons why this may be so. ________________________________________________________ ________________________________________________________ ______________________________________________________ [2]

(b) State whether can C radiates heat at a higher or lower rate than can B. Explain your answer. ______________________________________________________ [1]

6

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2

8. The figure below shows the position of an object, 0, and its image, I, formed in a plane mirror, M.

On the figure, draw two rays which leave O and reach the eye, E, after reflection at the mirror. [4] 9. In the circuit below, E is a battery of e.m.f. 6.0 V and negligible internal resistance. R1 and R2 are resistors, each of resistance 150 Ω. V1 is a high resistance voltmeter and A1 is an ammeter of negligible resistance.

What are the ammeter and voltmeter readings when the positive terminal of the voltmeter is connected at point F and G? [2] At F

At G

Ammeter reading at A1 / A Voltmeter reading at V1 / V

7

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 10. A horizontal steel wire is fixed at one end and is kept under tension by means of weight suspended over a pulley as shown in Fig A

wire

Fig A A 5 V d.c supply is connected to the wire between the fixed point and the pulley such that a current flows between the fixed point and the pulley. Magnets are placed near to the centre of the horizontal section of the wire in order to produce a magnetic field at right angles to the wire.

wire

Fig B The horizontal steel wire bends upwards as shown in Fig B. (a) On the fig B, draw the direction of the current flowing through the steel wire. [1] (b) State the effect on the bending of the wire when (i) the magnets are brought closer to wire, ____________________________ [1] (ii) the poles of the magnets are reversed, ____________________________ [1] (iii)the current along the wire is reversed. ____________________________ [1] 8

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 Section B Answer any two questions Write your answers on the separate answer paper provided 11. Two identical resistors, each of resistance 6.0 Ω, are to be connected between the terminals of a 2V cell. (a) The resistors are connected in series. (i) Calculate the total resistance of this circuit. (ii) Calculate the total power dissipated in each resistors .

[1] [2]

(b) The resistors are now connected in parallel. (i) Calculate the total resistance of this circuit. (ii) Calculate the current in each resistor.

[1] [2]

(c) Both resistors are wires made from the same material. Suggest 2 ways to double one of the resistances. [2] (d) The graph shows the results of an experiment to determine the resistance of another wire.

Find the resistance of the wire

[2]

9

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2 12. Fig. (a) shows a circuit breaker with the contact closed.

Fig. (a) Fig. (b) shows the same circuit breaker after a large current passes through the circuit.

Fig. (b) (a) Describe how the circuit breaker opens the circuit when the current becomes too large. [3] (b) Explain why the circuit breaker should be connected to the live wire in a household circuit. [2] (c) State and explain how should the number of coils in the solenoid be changed so that the circuit breaker trips (switch off) for a smaller current. [3] (d) If the iron core is replaced by steel, state and explain what would be the effect on the working of the circuit breaker. [2]

10

bbss/2009/Prelim/Sec4E5N/Science(5116)/P2

13. The figure below shows a ripple tank. The oscillating paddle is made to bounce up and down by a rotating motor. For each rotation of the motor one new wavefront is sent out. light source

(a) A series of alternate bright and dark lines can be seen on the screen below the tank. Suggest how this pattern is formed. [2] (b) Explain how you would measure the wavelength of the waves. Your explanation should include steps taken to ensure accuracy and precision of the measurement. [5] (c) Explain how you would use a ripple tank to demonstrate the refraction of waves with a plane wavefront. Draw a diagram to help your explanation. [3]

END OF PAPER Persisted?

11