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AP Physics – Optical Stuff – 55

I have found that when confronted with a difficult choice, the hardest thing to do is usually
the right thing to do.  --  Richard Edwin Reynolds

1.       A ball is rotated in a vertical circle as shown.  The ball has a mass of 1.50 kg, the very light-weight string is 85.0 cm in length.  The ball’s velocity at the top is the minimum speed needed to maintain the circular path.   (a) What is this minimum speed?

(b) Draw and label all forces acting on the ball at points A, B, and C on the drawing below.

(c) What will be the tension in the string when the ball is at point A?  (d) What will be the tension at point B?  (e) What will be the tension at point C.

2.      A beam of light, wavelength 585 nm in air, is incident on a block of crown glass at an angle of 28.5°.  Find (a) the speed of light in the glass (b) the angle of refraction and (c) the wavelength of the light in the glass.

3.      An AM radio signal is broadcast at a frequency of 1319 kHz.  (a) What is its wavelength?   (b) What is the period of the wave?

4.      A screen is separated from a double–slit setup by a distance of 2.15 m.  The slit spacing is 0.0150 mm.  The first-order maximum is 4.05 cm from the centerline.  Find (a) the wavelength, (b) the distance between adjacent fringes.

5.      Find the minimum film thickness for constructive interference in reflected light for a thin film.  The film’s index of refraction is 1.45.  It is illuminated by light that has wavelength of 585 nm.

6.     Construct the image on the drawing below via ray tracing. Describe the image.

7.      Construct the image on the drawing below via ray tracing. Describe the image.

8.     Construct the image for an object placed as shown below.

9.      A double convex thin lens has a focal length of  50.0 cm.  A 2.70 cm tall object is placed 18.0 cm from the lens, find (a) the image distance, (b) the magnification, (c) the image height.

10. A proton is fired into the midpoint of a field between two charged plates.  The initial velocity of the proton is 1.65 x 105 m/s.  The plates are a distance of 2.15 mm apart.  The potential difference for the plates is 215 V.  Determine where the proton will hit on the lower plate.

11.  A force is applied to a conducting rod so that it slides across a pair of conducting rails.  A uniform magnetic field of 2.17 T is directed into the page.  The rails are separated by 16.5 cm.  The rod is moving at a constant velocity of 10.2 m/s. The resistance of the system is 1.87 W.  Find the following:
(a) The induced emf in the moving rod, (b) the direction of the current through R, (c) the current through R, (d) The magnitude of the applied force needed to keep the rod moving at constant velocity, (e) The power dissipated by the resistor.