Two parallel-plate capacitors, identical except that one has twice the plate separation of the other, are charged by the same voltage source. Which capacitor has a stronger electric field between the plates? Which capacitor has a greater charge? Which has greater energy density? Explain your reasoning.

Draw a diagram comparing convection in a pot of water with convection in Earth's mantle. Relate the process of convection to plate movement.

If the energy stored by a $6 \mu \mathrm{F}$ capacitor is $1200 \mathrm{~J}$, find the charge $Q$ on each plate of the capacitor.

For $P=8.5 \mathrm{~kips}$, determine the minimum plate thickness $t$ required if the allowable stress is $18 \mathrm{~ksi}$.

To produce a polarized laser beam, a plate of transparent material is placed in the laser cavity and oriented so the light strikes it at the polarizing angle. Such a plate is called a Brewster window. Prove that if $\theta_{\mathrm{P} 1}$ is the polarizing angle for the $n_1$ to $n_2$ interface, then $\theta_{\mathrm{P} 2}$ is the polarizing angle for the $n_2$ to $n_1$ interface.

Under what conditions can the outer surface of a vertical cylinder be treated as a vertical plate in natural convection calculations?

Determine the mass of inertia about the y-axis for the parabolic plate of the previous problem. State the radius of gyration about the y-axis.

Why does toast have a better chance of landing jelly-side up if it is quickly shoved off the plate or table?(a) It falls faster than if slowly slipping from the plate and does not have time to rotate. (b) It moves in a parabolic path.(c) The torque due to the gravitational force about the trailing edge of the toast as it leaves the plate has very little time to change the toast’s rotational momentum.(d) The hand probably gives it an extra twist and the toast makes a full rotation instead of a half rotation.

A 1-mm-thick copper plate $(k=386 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K})$ is sandwiched between two 7-mm-thick epoxy boards $(k=$ $0.26 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K}$ ) that are $15 \mathrm{~cm} \times 20 \mathrm{~cm}$ in size. If the thermal contact conductance on both sides of the copper plate is calculated to be $6000 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K}$, find the error involved in the total thermal resistance of the plate if the thermal contact conductances are disregarded.

Two capacitors with $C_1=1.5 \mu \mathrm{F}$ and $C_2=2.5 \mu \mathrm{F}$ are connected in parallel. If the combined charge on both capacitors is $25 \mu \mathrm{C}$, what is the voltage across the capacitors?

Engine oil at $40^\circ C$ is flowing over a long flat plate with a velocity of 6 m/s. Determine the distance $x_{\mathrm{cr}}$ from the leading edge of the plate where the flow becomes turbulent, and calculate and plot the thickness of the boundary layer over a length of $2 x_{\mathrm{cr}}.$

A batter hits a fly ball which leaves the bat $0.90 \mathrm{~m}$ above the ground at an angle of $61^{\circ}$ with an initial speed of $28 \mathrm{~m} / \mathrm{s}$ heading toward centerfield. Ignore air resistance. $(a)$ How far from home plate would the ball land if not caught? $(b)$ The ball is caught by the centerfielder who, starting at a distance of $105 \mathrm{~m}$ from home plate just as the ball was hit, runs straight toward home plate at a constant speed and makes the catch at ground level. Find his speed.

A $\frac{1}{4}$-in steel plate having a thermal conductivity of $25 \mathrm{Btu} / \mathrm{h} \cdot \mathrm{ft} \cdot{ }^{\circ} \mathrm{F}$ is exposed to a radiant heat flux of $1500 \mathrm{Btu} / \mathrm{h} \cdot \mathrm{ft}^2$ in a vacuum space where the convection heat transfer is negligible. Assuming that the surface temperature of the steel exposed to the radiant energy is maintained at $100^{\circ} \mathrm{F}$, what will be the other surface temperature if all the radiant energy striking the plate is transferred through the plate by conduction?

A $0.40~\mu \mathrm{F}$ capacitor is connected to a $9.0~ \mathrm{V}$ battery. How much charge is on each plate of the capacitor?