Calculate the following: 4.9.1 The total resistance of the circuit. 4.9.2 The total current of the circuit. 4.9.3 The voltage drop across \( R_{1} \) resistor. 4.9.4 The voltage drop across \( R_{2} \) resistor. 4.9.5 Prove that \( V_{T}=24 \mathrm{~V} \) 4.9.6 What will happen to the current flow in resistor \( R_{1} \) if the resistance is doubled? 4.10 Calculate the power dissipated by an electric circuit which is supplied by a 220 V

- Which time function of velocity has a uniform non zero-acceleration at any time \( t \) ? \( \begin{array}{llll}\text { A. } v=9 t^{3} & \text { B. } v=9 t^{2} & \text { C. } v=9 t-4 t^{2} & \text { D. } v=9 t\end{array} \)

6) A 70 kg man steps onto a scale inside an elevator. What does the scale read if the elevator descends while slowing down at a rate of \( 3 \mathrm{~m} / \mathrm{s}^{2} \) ? a. 49 kg b. 70 kg c. 82 kg d. 91 kg

\( vf=vi+a.t \)

64 Un cubetto d'argento ha il volume di \( 4 \mathrm{~cm}^{3} \) e costa \( € 126 \), cioè \( € 3 \) al grammo. Un cubo di vetro ha volume di \( 7 \mathrm{~cm}^{3} \) e costa \( € 26,25 \), cioè \( € 1,50 \) al grammo. Qual è la differenza tra le densità dei due cubi? [8]

40 If a toy helicopter is moving at \( 12 \mathrm{~m} / \mathrm{s} \), how much energy does the 3 kg toy have? Show your work!