HCI Worksheet 1 Basic Ideas in Physics

Hwa Chong Institution Sec 3 (Physics) 1 Name: __________________________________________ Class: _________ Date: ____________ Sec 3 Physics Worksheet 1: Basic Ideas in Physics Multiple Choice Questions 1. A stopwatch hand stops in the position as shown. What is the reading? A 21.2 s B 22.4 s C 27.6 s D 32.0 s E 38.0 s N92/I/1 2 It takes 13.8 s for a pendulum to swing from X to Y and back again twenty times. What is the period of the pendulum? A 0.345 s B 0.690 s C 1.38 s D 4.60 s E 13.8 s

Hwa Chong Institution Sec 3 (Physics) 2 3 A student used a vernier caliper to measure the diameter of a wooden cylinder. The diagram shows an enlargement of the calipers scale. What was the reading recorded? A 2.40 cm B 1.64 cm C 0.62 cm D 0.42 cm 4 A student has been asked to calculate the volume of a piece of wire, which is about 80 cm long and about 0.2 cm in diameter. Which of the following instruments should the student use? Length Diameter A Metre rule Micrometer B Metre rule Vernier calipers C Micrometer Vernier calipers D Vernier calipers Micrometer N97/I/1 5 Which of the following physical quantity is measured using a micrometer? A current B length C time D weight N98/I/1 6 The diagram shows part of a micrometer screw gauge. What is the reading shown? A 5.31 mm B 5.79 mm C 5.81 mm D 6.31 mm N91/I/2

Hwa Chong Institution Sec 3 (Physics) 3 7 The diagram shows part of the vernier scale on a pair of calipers. Which reading is correct? A 2.74 cm B 3.10 cm C 3.26 cm D 3.64 cm N99/I/1 8 The diagram shows a micrometer screw gauge. What is the reading shown? A 5.25 mm C 7.02 mm B 5.48 mm D 7.48 mm N2000/I/1 9 The diagram shows a micrometer scale. Which reading is shown? A 5.64 mm C 7.16 mm B 7.14 mm D 7.64 mm N2002/I/1

Hwa Chong Institution Sec 3 (Physics) 4 10 One oscillation of a swinging pendulum occurs when the bob moves from X to Y and back to X again. Using a stopwatch, which would be the most accurate way to measure the time for one oscillation of the pendulum? A Time 20 oscillations and multiply by 20. B Time 20 oscillations and divide by 20. C Time one oscillation. D Time the motion from X to Y and double it. N2003/I/1 11 The diagram shows part of a vernier scale. What reading is correct? A 30.5 mm B 33.5 mm C 38.0 mm D 42.5 mm N2004/I/1

Hwa Chong Institution Sec 3 (Physics) 5 Discussion Questions Derived Quantity Formula S.I. unit Another common unit Area of a rectangle Density Average speed 1 Fill up the table with the appropriate formulas and units: 2 Fill in the blanks with units of the appropriate prefixes. (a) 1 kg = 103 ____ (c) 1 mA = 1 × ____ (b) 1 _____ = 10-6 s (d) 1 _____ = 109 W 3 When using the Vernier callipers, (a) state two precautions you would take in order to make your determ ination of the diameter of a coin as accurate as possible. (b) state two ad vantages of using this instrument compared with using a rule reading in millimetres for making this measurement. 4 When using the micrometer screw gauge, state the purpose of the ratchet.

Hwa Chong Institution Sec 3 (Physics) 6 5 A pile of 500 sheets of paper has a mass of 2 kg. The pi le is 300 mm long, 200 mm wide, and 50 mm thick. Calculate (a) the thickness of one sheet; (b) the mass of one sheet; (c) the volume of the pile; (d) the density of the paper; (e) the mass of a one-square-metre sheet of this paper. [Avison] 6 When a block of metal is hung in air from a spring balance, the reading is 9.6 N. (a) What is the weight of the block of metal? (b) Assuming that the weight of a 1 .0 kg mass is 10 N, calculate the mass of the block of metal?

Hwa Chong Institution Sec 3 (Physics) 7 (c) The figure shows a displacement can which has been filled with water. When the block of metal in (a) is lowered into the can until it is totally immersed in the water, 110 cm 3 of water overflows. Calculate the density of the metal. 7 The following figure shows a simple pendulum suspended from a clamp. (a) Describe briefly how you would use a stopwatch or a stopclock to determine, as reliably as possible, the period of oscillation of a pendulum. (b) A student obtains the following values for the time for 20 complete oscillations of a pendulum. 14.6 s 14.7 s 14.5 s 14.6 s 14.7 s Determine the period of the pendulum. N97/II/1 Pendulum bob

Hwa Chong Institution Sec 3 (Physics) 8 Further Questions (i) In a simple pendulum , what is the physical quantity that determines the period T of the oscillation? What is the relationship between T and that quantity? (ii) One important consideration when doing a pendulum experiment is to ensure that the maximum angle of swing must not exceed 10o. What is the reason for it? (iii) Imagine you are explaining what it meant by an oscillation of the pendulum to a Sec 1 student, how would you describe it? (iv) Why do we need to repeat the timing several times? (v) What is the most significant source of error in this experiment? (vi) The typical stopwatch used in the laboratory can measure up to centi or milliseconds. Should we take the readings to that level of precision? (vii) After a few swings, the amplitude of the oscillations becomes smaller as air resistance is dissipating energy from the pendulum. Will the period of the pendulum change in response? (viii) If the pendulum bob is changed to a more massive one, would the period T of the oscillation change?

Hwa Chong Institution Sec 3 (Physics) 9 8 In the opening scenes of the movie Raiders of the Lost Ark , Indiana Jones trie d to remove a gold idol from a booby -trapped pedestal. He replaced the idol with a bag of sand of approximately the same volume (see picture on left). (a) Calculate the ratio of the mass of the idol to the mass of the bag of sand. (Density of gold = 19.32 g/cm3; density of sand  2 g/cm3.) Ratio = ……………………… (ix) One way to improve on the readings of the period is to use a light-operated solid state switch instead of the human hand to start and stop the stopclock. The light switch is placed at the centre of the oscillation and will take note each time the bob passes in between the light switch. The light switch has a response time of a few nanoseconds. With reference to (vi), can we now take the readings to a milliseconds?

Hwa Chong Institution Sec 3 (Physics) 10 (b) Give a short explanation whether Jones will suc ceed in not activating the mass-sensitive booby trap? (c) In a later scene, he and an unscrupulous guide play ed catch with the idol. The volume of the idol was about 1.0 L (litre). If it were solid gold, what mass would the idol have? Mass of idol = …………………….. kg (d) Based on your answer in part (c), explain if it is plausible for a typical man to play catch with the idol?