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.

What is the dot product of vector \( j \) with a magnitude of 4 and a direction of \( 30^{\circ} \) and vector k with a magnitude of 10 and a direction of \( 15^{\circ} \) ? (Round your answer to the nearest tenth.)

22.Sebuah benda bermuatan \( \mathrm{q}=9 \times 10^{-5} \mathrm{C} \) dan mempunyai gaya elektrolisis \( 7,2 \mathrm{~N} \). maka kuat medan pada tempat benda tersebut berada adalah.. A. \( 1,2 \times 10^{-6} \mathrm{~N} / \mathrm{C} \) B. \( 4,2 \times 10^{-6} \mathrm{~N} / \mathrm{C} \) C. \( 5,0 \times 10^{-6} \mathrm{~N} / \mathrm{C} \) D. \( 8,0 \times 10^{-6} \mathrm{~N} / \mathrm{C} \)

85 Un pannello di MDF, una fibra di legno utilizzata per mobili componibili, ha spessore \( (14,0 \pm 0,2) \mathrm{mm} \) e forma rettangolare con lati \( (60,0 \pm 0,1) \mathrm{cm} \) e \( (80,0 \pm 0,1) \mathrm{cm} \); la sua massa è \( (5600 \pm 20) \mathrm{g} \). Le specifiche del prodotto in- dicano che il materiale ha densità \( 850 \mathrm{~kg} / \mathrm{m}^{3} \), con tolle- ranza dell' \( 1 \% \). Calcola la densità del pannello in base ai valori mi- surati.

2) ¿Qué aceleración adquiere si se le aplica el doble de fuerza que en el punto anterior? ¿Y si se le aplica el triple? Hacé los cálculos aplicando la fórmula, luego justificalo a través del enunciado de la Segunda Ley.

What will happen to the speed of a ball after it is thrown upward into the air? \( \begin{array}{ll}\text { A. Increnses } & \text { C. increases and then d }\end{array} \)