A U-tube manometer filled with water (density = $1000 \mathrm{~kg} / \mathrm{m}^{3}$ ) shows a height difference of $25 \mathrm{~cm} .$ What is the gauge pressure? If the right branch is tilted to make an angle of $30^{\circ}$ with the horizontal, as shown in Fig. $\mathrm{P} 1.77,$ what should the length of the column in the tilted tube be relative to the U-tube?