An anxious physicist worries that the two metal shelves of a wood frame bookcase might obtain a high voltage if charged by static electricity, perhaps produced by friction. (a) What is the capacitance of the empty shelves if they have area 1.00 × 102 m2 and are 0.200 m apart? (b) What is the voltage between them if opposite charges of magnitude 2.00 nC are placed on them? (c) To show that this voltage poses a small hazard, calculate the energystored. (d) The actual shelves have an area 100 times smaller than these hypothetical shelves. Are his fears justified?

1. (a) What is the capacitance of a parallel plate capacitor having plates of area 2 m² that are separated by 0.02 mm of neoprene rubber (K = 6.7)? C = uF (b) What charge does it hold when 9 V is applied to it? Q = C (c) Compare this charge to the case when no dielectric is present. The charge when no dielectric is present is Qdielectric is present. no - dielectric compared to when a dielectric

A professor designing a class demonstration connects a parallel-plate capacitor to a battery, so that the potential difference between the plates is 225 V. Assume a plate separation of d = 1.47 cm and a plate area of A = 25.0 cm². When the battery is removed, the capacitor is plunged into a container of distilled water. Assume distilled water is an insulator with a dielectric constant of 80.0. (a) Calculate the charge on the plates (in pC) before and after the capacitor is submerged. (Enter the magnitudes.) before after AV f (b) Determine the capacitance (in F) and potential difference (in V) after immersion. Cf= = = (c) Determine the change in energy (in nJ) of the capacitor. AU = nJ AV f (d) What If? Repeat parts (a) through (c) of the problem in the case that the capacitor is immersed in distilled water while still connected to the 225 V potential difference. Calculate the charge on the plates (in pC) before and after the capacitor is submerged. (Enter the magnitudes.) before after…

(a) When a 8.00-V battery is connected to the plates of a capacitor, it stores a charge of 28.0 ?C. What is the value of the capacitance? ?F(b) If the same capacitor is connected to a 15.0-V battery, what charge is stored? ?C

A small object with a mass of 3.81 mg carries a charge of 21.8 nC and is suspended by a thread between the vertical plates of a parallel-plate capacitor. The plates are separated by 5.67 cm. If the thread makes an angle of 12.7° with the vertical, what is the potential difference in volts between the plates?   Round your answer to 1 decimal place.

A small object with a mass of 4.68 mg carries a charge of 33.7 nC and is suspended by a thread between the vertical plates of a parallel-plate capacitor. The plates are separated by 4.18 cm. If the thread makes an angle of 10.5° with the vertical, what is the potential difference in volts between the plates? Round your answer to 1 decimal place.