An iron rod of length 30cm is heated through 50 Kelvin. Calculate it's increase in length (linear expansivity of iron=1.2*10raise to power -5 ​

An air-filled capacitor is formed from two long conducting cylindrical shells that are coaxial and have radii of 26 mm and 103 mm. the electric potential of the inner conductor with respect to the outer conductor is - 700 v (k = 1/4πε 0 = 8.99 × 109 n · m2/c2) the energy stored in a 1.0-m length of this capacitor is closest to