Please Fill in the Blanks and Answer the Short Questions/Problems When Appropriate

Leader: German Parada Dead Week Unit 1 review Course: Phys 222 Supplemental Instruction Instructor: Dr. Soeren Prell Iowa State University Date: 4/28/2014 Please fill in the blanks and answer the short questions/problems when appropriate.

Pressure is defined as ______, and it has units of ____. When an object is submerged in a fluid of density ρ, it experiences pressure dependent on __, ___ and ___, as indicated in the following equation where P is the ______and (P-Po) is called the ______.

Derived from that equation, Pascal’s principle indicates that:

Due to the difference in hydrostatic pressures, an object submerged in a fluid will experience an ______force called ______, which is described in this equation,

When incompressible fluids flow, the volumetric flow rate and velocity are related by the ______, which can be written as . Also, for incompressible fluids, the conservation of energy allows for the derivation of the Bernoulli equation, which relates ______, ______, ______and fluid ______, as follows

a – Two solid spheres with the same mass but different densities (both lower than that of water) are tied with rope to the bottom of a pool. If the density of one is three times less than the other, what is the ratio of the tension of the ropess?

b – Ethanol (ρ = 0.789g/mL) flows in a pipe with decreasing diameter. If the final diameter is four times narrower than the initial diameter, is the final pressure greater or smaller than the initial one? How much greater/smaller?

The force between two point charges increases as ______increases and ______decreases, as indicated by the equation . If more than one charge is present, the force vectors can be ______as stated by the ______.

A more general way of describing forces is by introducing the concept of ______, obtained by dividing the force over the charge of a test charge. Then, for a point charge, the expression for the E-field is . Graphically, the E-filed is represented by ______, which start at ______charges and end at ______. For multiple charges, the E-field can also be ______.

To find the E-field for more complex charge, ______can be used. This law relates the ______charge and the E-field, as follows . Using this law, the following table can be completed,

Object Charged sphere Surface of charge Line of charge E-field

Supplemental Instruction 1060 Hixson-Lied Student Success Center v 294-6624 v www.si.iastate.edu Where the charge densities are,

To calculate the energy and work for electrical systems, a concept called ______can be used. The following equation is used to calculate the potential difference between two points . Usually, the potential at _____ is set at zero. Also, it is possible for find E-field from potential using

For a point charge, the expression for potential at a point r away is For constant E-field, the expression for potential is

For conducting objects, the ______is always zero and the potential is ______.

a- Two identical charges of 30nC are located at (0,0) and (3,0). What is the direction and magnitude of the E-field at (3,4)?

b – Two parallel lines of charge separated a distance L have charge densities λ1 = -3mC/m and λ2 = -6mC/m. Where would the net E-field be zero?

c- There are two spheres with the same total charge and radius. However, on is conductive and while the other is non-conductive and has a uniform charge distribution throughout its volume. Will the graphs of V(r) for these two spheres be different? How so?

Devices used to store charge are called ______. The measurement of how well the charge is stored is termed ______(the unit is ___) and can be found by this equation .

Different equations can be used to find capacitance for different geometries, as seen below, Geometry Parallel Plate Concentric cylinders Concentric Spheres Capacitance

The energy stored by a capacitor can be found with the following equations

In reality, the energy is stored in the ______inside the capacitor, as shown in the following equation

If various capacitors are connected in parallel, the equivalent capacitance is found using whereas the following equation is used if connected in series

If instead of vacuum another material (dielectric) is placed inside the capacitor, the capacitance expressions need to be multiplied by the ______. This ______the capacitance of the devices. However, if the E-field applied across the capacitor is too high, a phenomenon called ______takes place, damaging the capacitor.

a – The plates of a parallel plate capacitor connected to a battery of are pulled away. If the final separation is three times the initial separation, how does the energy stored change?

b – The dielectric material (k = 3.5) between the plates of an isolated concentric cylinder capacitor is removed. How does the voltage of this capacitor change? What about the energy?