Fig. 15-5 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have an electric flux of +q/?o through them?

A transverse periodic wave is represented by the equation y(z, t) = 2.0 cm sin(1,200 rad/s t - 20.0z). Another transverse wave is represented by the equation y(z, t) = 2.0cm sin(1,200 rad/s t + 20.0z). What is the equation that represents the superposition of the two waves?

A. y(z, t) = 4.0 cm sin(1,200 rad/s t - 20.0 z)
B. y(x, t) = 4.0 cm sin(1,200 rad/s t) cos(20.0x)
C. y(x, t) = +4.0 cm cos(1,200 rad/s) sin(20.0x)
D. y(x, t) = +4.0 cm cos(1,200 rad/s) + (20.0x)

A crystal diffracted a beam of electrons. The crystal spacing was 0.18 nm and the maximum scattering occurred at 80.° relative to the surface normal. The electrons were directed normally onto the crystal

(a) What is the wavelength of the electrons? (b) What potential difference accelerated the electrons?

Find the frequency of X-rays of wavelength 1 Å = 10-10 m

a. 3 × 10^18 Hz b. 3 × 10^10 MHz c. 6 × 10^9 Hz d. 3 × 10^8 Hz e. 3 × 10^20 Hz

The activation enthalpy for vacancy diffusion along a grain boundary is _____________than that for diffusion through the bulk.

Fill in the blank(s) with the appropriate word(s).