A rod of length 2.3 m, with a rectangular cross section (1.5mm x 3.0 mm) is made of a material with a resistivity of 6.1 × 10^-8 Ohm.  A potential difference of 5.0 V is places across the ends of the rod. a.  Draw a clear physics diagram of the problem. b.  At what initial rate is heat generated in the rod? c.  Will the rate from part (b) increase, decrease, or remain constant over time, as the rod remains connected to the 2.5 V potential difference? Explain briefly

A length of aluminum wire is connected to a precision 10.00-V power supply, and a current of 0.4212 A is precisely measured at 23.5 °C. The wire is placed in a new environment of unknown temperature where the measured current is 0.3758 A. The temperature coefficient of resistivity of aluminum is 0.00429 (°C) -¹ Part A What is the unknown temperature? Express your answer using three significant figures. T= Submit G| ΑΣΦ Request Answer ? °C Review I Constants

6. High energy proton beams can be used to kill cancer cells. The beam consists of protons with 2.5x10-" J and a current of 75 nA. Assume all the protons stop in the tumor. A total of 3.4x10-3 J is needed to treat the tumor. A. How fast are the protons moving? B. What is the energy of each proton and the total energy needed in eV? C. How many protons reach the tumor each second? D. How long should the beam run to deliver the required amount of energy to the tumor?

Q1: A conductive wire has a resistivity of (0.649x10-8(Q.m)') at room temperature are (5.8x10* ) conduction electron/m3.Calculate the mobility, resistivity and relaxation time of electrons.