3. Waves
A section of Physics, 0625
Listing 10 of 1440 questions
shows a metal strip, held in a clamp. X metal strip clamp Y Z The end of the strip is pulled down and released, so that the strip vibrates. X and Z are the extreme positions of the end of the strip during this vibration. Y is the mid-position. Explain what is meant by the frequency of vibration of the strip, the amplitude of vibration of the end of the strip. shows two tall buildings, A and B, that are 99 m apart. 33 m 99 m P A B (not to scale) A student stands at P so that his distance from building A is 33 m. After clapping his hands once, he hears several echoes. The speed of sound in air is 330 m / s. Calculate the time interval between clapping his hands and hearing the first echo, time = the third echo. time = Write down an approximate value for the speed of sound in water, speed = in steel. speed = shows a dolphin in water emitting a sound wave of frequency 95 kHz. (not to scale) Using your value from , calculate the wavelength of this sound wave. wavelength =
0625_s15_qp_32
THEORY
2015
Paper 3, Variant 2
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An electric kettle contains 600 g of water at 20 °C. The heater in the kettle operates at 240 V. The specific heat capacity of water is 4200 J / (kg °C). The current in the heater is 12 A. Calculate the time taken for the temperature of the water to rise to 100 °C. time = State one assumption you made in your calculation in . Using the apparatus shown in , describe an experiment to demonstrate good and bad emitters of thermal radiation. Include the expected results and the conclusion. You may use a diagram. a ruler supply of hot water 2 thermometers metal water bottle black side white side The graph in represents a wave on a rope. 8.0 6.0 4.0 2.0 distance along rope / cm vertical position / cm Using , determine the amplitude of the wave, amplitude = the wavelength of the wave. wavelength = A wave travelling on the surface of water has a wavelength of 2.5 cm and a speed of 8.0 cm / s. Calculate the frequency of the wave. frequency = The wave in approaches a barrier that has a large gap in its centre. shows the crests of the wave viewed from above. direction of wave travel wave crest λ barrier gap barrier The gap in the barrier is larger than the wavelength λ. On , draw the pattern formed by three crests after the wave passes through the gap in the barrier. Water is added to the tank and the speed of a wave in the deeper water is greater than that in the shallower water. The frequency of the wave remains constant but its wavelength is different. 1. State and explain how the wavelength in the deeper water has changed. 2. Apart from the change in wavelength, describe one other difference in the pattern formed by the crests after the wave passes through the gap.
0625_s17_qp_42
THEORY
2017
Paper 4, Variant 2
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Questions Discovered
1440