Homework Problem 5.6 The electric potential in a region of space has the value V(z) = yz^3 where y = 25 V/m^3 is a constant. Compute the electric field at

the point (0,0,5.0 cm). \text { (a) } \vec{E}=-3.9 \times 10^{-5} \frac{\mathrm{N}}{\mathrm{C}} \text { (b) } \vec{E}=-3.1 \times 10^{-3} \frac{\mathrm{N}}{\mathrm{C}} \hat{\mathrm{z}} \text { (c) } \vec{E}=-1.25 \times 10^{-1} \mathrm{~N} \hat{\mathrm{c}} \text { (d) } \vec{E}=-1.9 \times 10^{-1} \frac{\mathrm{N}}{\mathrm{C}} \hat{\mathrm{z}} \text { (e) } \vec{E}=0