A camera is equipped with a telephoto lens that has a focal length of $200 \mathrm{~mm}$. Repeat part (c) of Challenge 8 for this situation.

In a double-slit interference experiment, a special lamp emitting yellow light from heated sodium atoms is used to produce an interference pattern on a screen located $1.50$ m from a pair of slits separated by $0.10 \mathrm{~mm}$. If the distance between adjacent bright regions in the resulting pattern is $8.84 \mathrm{~mm}$, what is the wavelength of the sodium light?

A small object is placed to the left of a convex lens and on its optical axis. The object is $30 \mathrm{~cm}$ from the lens, which has a focal length of $10 \mathrm{~cm}$. Determine the location of the image formed by the lens. Describe the image.

You can determine the index of refraction of a substance by determining its critical angle. (a) Calculate the index of refraction of a substance that has a critical angle of $68.4^{\circ}$ when submerged in water? What is the substance, based on the given Table. (b) What would the critical angle be for this substance in air?

How would figure mentioned $\mathrm{a}$ be different if the glass were replaced by water or by diamond?

In what ways do you think the physical environment influenced cultural patterns and the distribution of culture groups in West and Central Africa?

The blackbody radiation emitted from a furnace peaks at a wavelength of $1.2 \times 10^{-6} \mathrm{~m}(0.0000012 \mathrm{~m})$. What is the temperature inside the furnace?

The generator at a power plant produces $A C$ at 24,000 V. A transformer steps this up to $345,000 \mathrm{~V}$ for transmission over power lines. If there are 2,000 turns of wire in the input coil of the transformer, how many turns must there be in the output coil?

Consider a circuit that consists of a real battery with an emf $\varepsilon$ and an internal resistance of r connected to a variable resistor R. (a) In order for the terminal voltage of the battery to be equal to the emf of the battery, what should the resistance of the variable resistor be adjusted to? (b) In order to get the maximum current from the battery, what should the resistance variable resistor be adjusted to? (c) In order for the maximum power output of the battery to be reached, what should the resistance of the variable resistor be set to?

An electric clothes dryer is rated at $4,000 \mathrm{~W}$. How much energy does it use in $40 \mathrm{~min}$ ?

An electric eel can generate a 400-V, 0.5-A shock for stunning its prey. What is the eel's power output?

A current of $12 \mathrm{~A}$ flows through an electric heater operating on $120 \mathrm{~V}$. What is the heater's resistance?

During 30 seconds of use, $250 \mathrm{C}$ of charge flow through a microwave oven. Compute the size of the electric current.

Compute the frequency of an EM wave with a wavelength of 1 in. $(0.0254 \mathrm{~m})$.