Name: PHYS122 Hourly Exam 1 1. A 0.500 kg block is attached to a spring on a frictionless horizontal surface. The block is pulled to stretch the spring by 10 cm, and then gently released. A short time later, as the block passes through the equilibrium position; its velocity is 1 m/s. (a). What is the block’s period of oscillation? (b). What is the block’s speed at the point where the spring is compressed by 5 cm? 2. Astronauts visiting Mars measure the period of the pendulum to be 4.0 seconds. (a). What will be the period be if they make the string four times as large? (b). What will the period be if they make the mass four times as large?PHYS122 Exam 1 -2- 3. Two springs are tied together. A transverse wave is generated on the heavier spring. The wavelength is 0.20 m. When the wave reaches the point where the springs are attached, a wave travels along the lighter spring at a speed of 5.0 m/s. A wave with small amplitude also reflects along the heavier spring at a speed of 7.5 m/s. (a). Will the reflected wave be in phase (erect) or out of phase (inverted)? (b) What is the frequency of the wave on the heavier spring? (c) What is the wavelength of the travelling wave on the lighter spring? (d) Now, suppose a pulse is sent from the lighter spring to the heavier spring. What will be the orientation of the reflected pulse?PHYS122 Exam 1 -3- 4. Two wave pulses are approaching each other. (a) Sketch the resulting pulse at three different moments during the interfe-rence. Were any nodes generated? (b) Sketch what the pulses will look like after the interference has taken place.PHYS122 Exam 1 -4- 5. An object is placed 30 mm in front of a lens. An image of the object is located 90 mm behind the lens. a. Is the lens converging or diverging? Explain your reasoning. b. What is the focal length of the lens? c. On the axis below, draw the lens at position x = 0. Draw at least two rays and locate the image to show the situation described above. d. Based on your diagram in c, describe the image by answering the following questions in the blank spaces provided. Is the image real or virtual? Is the image smaller than, larger than or same size as the object? Is the image inverted or upright compared to the object?PHYS122 Exam 1 -5- e. The lens is replaced by a concave mirror of focal length 20 mm. On the axis below, draw a mirror at position x = 0 so that a real image is formed. Draw at least two rays and locate the image to show this situation.PHYS122 Exam 1 -6- 6. A ray of light is incident on a piece of glass with index of refraction ng = 1.60 with and angle of θa = 30°. The index of refraction of the air is 1.00 (a) how fast is the light travelling through the glass? (b) At what angle will the ray refract into the glass with respect to the normal? (c) Sketch the refracted ray through the glass and the ray as it is exiting from the glass at the other surface. What angle with the exiting ray make with the normal? Bonus: Find the incidence angle that will not allow the refracted ray to pass through the second surface from glass back into air ng na θaPHYS122 Exam 1 -7- 7. To measure the speed of a golf cart, the clever caddy places a loudspeaker on the cart and produces a constant 500 Hz signal. As his buddy is driving the cart toward him, the caddy turns on another loudspeaker that also produces the same 500 Hz signal. He measures a beat frequency of 25 Hz. (a) How fast is the golf cart travelling? (b). What is the intensity of the sound from one of the loudspeakers if the caddy measures the intensity level to be 50 dB? (c). What will be the intensity level (in dB) if he is four times the distance from the loudspeaker? 8. Is light a stream of particles or a number of waves? Justify your
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