In this worksheet, we will practice calculating the deflection of light rays at interfaces of materials within which light travels at different speeds.
A ray of light is shown going from air (refractive index of 1.00) through crown glass (refractive index of 1.52) into water (refractive index of 1.33), such as going into a fish tank. Calculate the amount the ray is displaced by the glass , given that the incident angle is and the glass is 1.00 cm thick.
In which substance from this table is the speed of light m/s?
|Gases at , 1 atm|
|Ice (at )||1.309|
- A Fluorite
- B Ethanol
- C Plexiglas
- D Ice at ()
- E Benzene
A laser emits red light that has a wavelength of 633 nm. The light is transmitted into glass in which it propagates at m/s, while retaining the same frequency that it had while propagating in air.
What is the frequency of the light?
- A Hz
- B Hz
- C Hz
- D Hz
- E Hz
What is the wavelength of the light in the glass?
Lunar astronauts have placed a corner reflector on the Moon’s surface. A laser beam from Earth is periodically fired at the reflector and reflected back by it to the beam’s source. The distance to the Moon is calculated from the time between emitting the beam and detecting its reflection. The distance from Earth to the Moon is also calculated by parallax measurement and found to be m. The distance found using the reflected laser measurement of the distance is found to be greater than the distance found by parallax as the light is slowed slightly when it moves through Earth’s atmosphere. Find the percentage increase in the round-trip time taken by the laser beam due to the effect of Earth’s atmosphere. Use a value of 30.0 km for the thickness of Earth’s atmosphere and a value of 1.00394 for the average refractive index of the atmosphere.
A light ray traveling through water is incident on a plane glass surface at an angle from a line normal to the surface. The light ray propagates through the glass at an angle of from the normal of the surface. Find . Use a value of 1.33 for the refractive index of water and use a value of 1.52 for the refractive index of glass.
A secret agent is pursued through some woodland by an armed guard carrying a gun with a laser targeting sight. The agent attempts to lose the pursuing guard by diving into a lake. While underwater, the agent sees the laser beam from the guard’s gunsight in the water near him and notes that the beam is at an angle of to the vertical. Find the angle above the horizontal at which the laser beam must be incident on the surface of the water. Use a value of 1.33 for the refractive index of water. Assume that the surface of the lake is perfectly horizontal.
An object made of an unknown substance is immersed in water. A ray of light is directed at the object at an angle of from the object’s surface. The light ray propagates within the substance at an angle of from the normal to the object’s surface. Find the refractive index of the substance. Use a value of 1.33 for the refractive index of water.
A light ray propagating in water strikes the surface of a gemstone at an angle of from the normal to the surface. The light ray propagates within the gemstone at an angle of from the normal to the surface. Find the speed of light in the gemstone. Use a value of 1.33 for the refractive index of water.
- A m/s
- B m/s
- C m/s
- D m/s
- E m/s
A light ray propagating in air is incident on an air-glass interface, and after propagating through glass, it is incident on a glass-water interface, as shown. Assuming that the angle from the normal of the air-glass interface at which the light ray strikes the glass surface is , find the angle from the normal to the glass-water interface at which the light ray propagates in water. Use a value of 1.33 for the refractive index of water and a value of 1.52 for the refractive index of glass.