(10) A uniform rod of weight 20 newton which is movable around a hinge at on its ends is pulled a side by a horizontal force of magnitude 10 newton acting on the other end, then the measure of the angle of inclination of the rod to the vertical when it is in equilibrium \( =\ldots \ldots \ldots \) \( \begin{array}{llll}\text { (a) } 60^{\circ} & \text { (b) } 45^{\circ} & \text { (c) } 30^{\circ} & \text { (d) } 90^{\circ}\end{array} \)

body placed on a rough horizontal level \( W=75 \mathrm{~N} \) horizontal force affected 50 N Makes it about to move en the coefficient of friction equals \( \begin{array}{llll}\text { 1) } \frac{1}{3} & \text { 2) } \frac{2}{3} & \text { 3) } \frac{3}{4} & \text { 4) } \frac{1}{4}\end{array} \)

Essay problem a body placed on rough horizontal level and two horizontal coplanar forces affected on it \( 6,10 \mathrm{~N} \) angle between them \( 60^{\circ} \) then the body's about to move if friction coefficient \( \frac{2}{3} \) then body weight \( =\ldots, \mathrm{N} \)

4. When you descend in a plane, your ears pop. Is air moving into your ears or out of them when they pop? 5. Explain why a balloon gets bigger as you put more molecules of gas into it at a constant temperature.

Question 6/13An air tank is exposed to ambient temperature.If you set the air pressure of the tank to 35 psi for a leak test and find that 24 hours later the tank's pressure has increased, what could've happened?The tank leakedThe tank drew in additional airThe ambient temperature increasedThe ambient temperature decreased

3) if \( \overrightarrow{F_{1}}, \overrightarrow{F_{2}}, \overrightarrow{F_{3}} \) are 3 forces that meets at a point and equilibrium: then the resultant of \( \overrightarrow{F_{1}}, \overrightarrow{F_{2}} \) equal : \( \begin{array}{lll}\text { 1) } \overrightarrow{F_{1}}, & \text { 2) } \overrightarrow{F_{1}}+\overrightarrow{F_{2}} & \text { 3) } \overrightarrow{F_{3}}\end{array} \)