Physics Electrostatic Moodle
Electric Field Equation 1
E = (KQ)/(d^2)
Electric Field Equation 2
E = (N)/(q)
Fill in the blank on the chart
Electric Field= 2E5 Force experienced= .4 Electric Field= 4E5 Force experienced= .8 Test Charge= 1.5 E-6, Electric Field= 4E5 Force experienced= .1 Force experienced= .2, Electric Field 1E5 Test Charge= 1E-6, Electric Field= 1E5
Electrostatic Force Equation
F = (KQq)/(d^2)
The standard metric units of measurements of electric field strength are ________.
N/C
Use your understanding of electric field lines to identify the charges on the objects in the following configurations.
OUT is POSITIVE IN is NEGATIVE
Two charged objects have an attractive force of 0.94 N. If the charge of one of the objects is increased by a factor of four, and the distance separating the objects is doubled, then what is the new force?
-.94 N Force is same Answer is negative due to it being attractive
Two charged objects have a repulsive force of 0.94 N. If the charge of one of the objects is doubled, then what is the new force?
1.88 N Multiply the force by a factor of 2
A balloon with a charge of 9.3xE-5 C is held a distance of 0.24 m from a second balloon having the same charge. Calculate the magnitude of the repulsive force.
1349.9 N (8.99E9 x 9.3E-5 x9.3E-5)/(.24)^2
Suppose that two equally charged spheres attract each other with a force of -0.765 N (- means attractive) when placed a distance of 40.2 cm from each other. Determine the magnitude of the charge of the spheres.
3.71E-6 C Square root of ((-.0765 x (.402)^2) / 8.99E9)
A test charge of +3.1E-6 C experiences a force of 0.15 N. The electric field strength is ________.
4.84E4 N/C
A test charge of +3.1x10-6 C experiences a force of 0.3 N. The electric field strength is ________.
9.68E4 N/C
An object with a charge of 4.2E-4 C creates an electric field. A test charge of 3.1E-6 C experiences a force of 0.3 N. The electric field strength is ________.
9.68e4 N/C
Complete the following statements to illustrate your understanding of the three types of charge interactions: Oppositely charged objects ________ Like charged objects ________ A charged object and a neutral object will ________
attract repel attract
What is true of atoms in terms of being neutral, negatively charged, and positively charged is also true of objects. An object that is negatively charged must have ________ electrons compared to its protons. An object that is positively charged must have ________ electrons compared to its protons. An object that is electrically neutral must have ________ electrons compared to its protons.
more, less, the same number of
For math related problems
Answers may vary depending on the numbers given
An object with a charge of 2.1E-4 C creates an electric field. A test charge of 3.1E-6 C experiences a force of 0.15 N. The electric field strength is ________.
4.84E4 N/C
An object with a charge of 2.1E-4 C creates an electric field. A test charge of 6.2E-6 C experiences a force of 0.3 N. The electric field strength is ________.
4.84E4 N/C
Summarize these verbal statements by inserting >, <, or = symbols into the blanks below: Negatively charged: # of e- ________ # of p+ Positively charged: # of e- ________ # of p+ Electrically neutral: # of e- ________ # of p+
> < =
An object becomes charged due to an excess or deficiency (shortage) of electrons. Knowing the exact number of excess or deficient electrons in an object allows one to determine the object's charge. The charge of one electron is 1.6x10-19 C. Use this to determine the charge of the following objects. A 1.0 x 103 excess electrons B 1.0 x 106 deficient electrons C 2.0 x 109 excess electrons D 2.5 x 108 deficient electrons E 6.82 x 1012 excess electrons
A 1.0 x 103 excess electrons Answer= -1.6E-16 B 1.0 x 106 deficient electrons Answer= 1.6E-13 C 2.0 x 109 excess electrons Answer= -3.2E-10 D 2.5 x 108 deficient electrons Answer= 4E-11 E 6.82 x 1012 excess electrons Answer= -1.0912E-6
A 2.6 μC charge and a -7.8 μC charge experience an attractive force of -0.51 N. Determine their separation distance.
.598 m Square root of (8.99E9 x 2.6E-6 x -7.8E-6) / -.51
Two charged objects have an attractive force of 0.94 N. If the charge of one of the objects is tripled and the distance separating the objects is tripled, then what is the new force?
-.313 N Multiply by a factor of (1/3) or Divide by a factor of 3 Answer is negative due to it being attrative
Calculate the electrical force (in Newtons) exerted between a 22 gram balloon with a charge of -3.0 μC and a wool sweater with a charge of 6.3 μC; the separation distance is 0.56 m.
-.54 N (8.99E9 x -3.0E-6 x 6.3E-6) / (.56)^2
A balloon has been rubbed with wool to give it a charge of -2.8E-6 C. A plastic tube with a charge of 3.9E-6 C is held a distance of 0.43 m above the balloon. Determine the electrical force of attraction between the tube and the balloon.
-.58 N
If there is an acceleration, then calculate its value. If there is no acceleration, enter "0". If the acceleration is down, make the answer negative. If the acceleration is up, make the answer positive.
-8.47 m/s/s
Two charged objects have a repulsive force of 0.94 N. If the distance separating the objects is tripled, then what is the new force?
.104 N Divide the force by a factor of 9
Two charged objects have a repulsive force of 0.94 N. If the distance separating the objects is doubled, then what is the new force?
.235 N Divide the force by a factor of 4
Two charged objects have a repulsive force of 0.94 N. If the charge of one of the objects is doubled, and the distance separating the objects is doubled, then what is the new force?
.47 N Multiply by a factor of .5 or Divide by a factor of 2
Anna Litical is performing a physics lab in which she charges a variety of materials and test to determine their charge by bringing them near a negatively charged balloon and near some neutral paper bits at rest on the table. Help Anna draw conclusions from her observations by selecting +, -, or 0 (neutral) (or a combination of these if absolute conclusiveness is not possible. Object A is observed to attract the paper bits; object A must be ________ Object B is observed to attract the balloon; object B must be ________ Object C is observed to repel the balloon; object C must be ________ Object D is observed to attract both the paper bits and the balloon; object D must be ________ Object E is observed to attract the paper bits and repel the balloon; object E must be ________
+ or - + or 0 - + -
Two charged objects have an attractive force of 0.94 N. If the distance separating the objects is quadrupled, then what is the new force?
-.05875 N Divide the force by a factor of 16 Answer is negative due to it being attractive
Two charged objects have a repulsive force of 0.94 N. If the distance separating the objects is halved, then what is the new force?
3.76 N Multiply by a factor of 4 or Divide by a factor of .25
The direction of the electric field vector is defined as: Select one or more: a. the direction a + test charge would move b. away from the + charge c. away from the - charge d. toward the + charge e. the direction a - test charge would move f. toward the - charge
a. the direction a + test charge would move b. away from the + charge f. toward the - charge
Balloon Conclusive evidence to conclude that the charge is +, -, or 0 A = ________ B = - C = ________
+ +
Electric field lines begin on _________ charges or at infinity and terminate on ________ charges or infinity. The number of lines that emanate from a charge or approach a charge depends upon ________. At locations where a line meets the surface of a charge, the lines are drawn in a ________ direction. The strength of the electric field is ________ wherever the lines are closest together.
+ - electric field strength radial greatest
Balloon Conclusive evidence to conclude that the charge is +, -, or 0 A = ________ B = - C = ________
+ or 0 -
Balloon Conclusive evidence to conclude that the charge is +, -, or 0 A = ________ B = - C = ________
+, -, 0 + or 0
Two charged objects have a repulsive force of 0.94 N. If the charge of both objects is doubled and the distance separating the objects is doubled, then what is the new force?
.94 N Force is the same
Two charged objects have a repulsive force of 0.94 N. If the charge of both of the objects is doubled, then what is the new force?
3.76 N Multiply the force by a factor of 4
Observe the electric field lines below for various configurations. Rank the objects according to which has the greatest magnitude of electric charge; beginning with the smallest charge.
OUT is POSITIVE IN is NEGATIVE MORE LINES the LARGER CHARGE LESS LINES the SMALLER CHARGE
Object C attracts B, Object D repels C, Object E attracts D and repels F, Object F attracts A. Jean knows that object a is negatively charged and object B is electrically neutral. What can Jean Yuss definitively conclude about the charges on the other objects? Object C is ________ Object D is ________ Object E is ________ Object F is ________
Object C is - Object D is - Object E is + Object F is +
During a physics lab, a plastic strip was rubbed with cotton and became positively charged. The correct explanation for why the plastic strip becomes positively charged is that Select one: a. the plastic strip acquired extra protons from the charging process. b. the plastic strip acquired extra protons from the cotton. c. protons were created as the result of the charging process. d. the plastic strip lost electrons to the cotton during the charging process.
d. the plastic strip lost electrons to the cotton during the charging process.
Construct a free-body diagram showing all the forces acting on the 400 gram balloon. The balloon will accelerate ________.
down
In one part of the room, there are two balloon- one hanging straight down and the other being attracted to it. This is evidence that: Select one: a. ...nonsense! This would never happen if the balloons are identical and simply suspended by strings. They will attract each other and both be deflected from a vertical orientation. b. balloon A is neutral and balloon B is negative c. balloon A is charged and balloon B is neutral d. balloon A is neutral and balloon B is positive e. balloon B is charged and balloon A is neutral
a. ...nonsense! This would never happen if the balloons are identical and simply suspended by strings. They will attract each other and both be deflected from a vertical orientation.
a. If the charge of the test charge, q, is doubled, then it will experience ________ force; the electric field strength at this location will be ________the original value. b. If the charge of the object Q is doubled, then the test charge will experience ________ force; the electric field strength at this location will be ________ the original value. c. If the distance between the charge and the test charge is doubled, then the test charge will experience ________ force; the electric field strength at this location will be ________ the original value.
a. 2x and the same as b. 2x and 2x c. 1/4th and 1/4th
As you look around the room, you observe two other balloons being pushed away from each other as shown below. The repulsion of these balloons from one another provides evidence that: Select one: a. both balloons are charged with the same type of charge b. both balloons are charged with the opposite type of charge c. both balloons are charged- either with the same type or opposite type of charge d. only one balloon is charged; the other is neutral e. at least one balloon is charged; the other is either charged or neutral.
a. both balloons are charged with the same type of charge
Your physics teacher has prepared the room for the class's entry by suspending several inflated balloons from the ceiling. Upon entering the physics room, you observe two balloons being drawn toward each other as shown below. The attraction of these balloons for one another provides evidence that: Select one: a. only one balloon is charged; the other is neutral b. both balloons are charged with the same type of charge c. both balloons are charged with the opposite type of charge d. at least one balloon is charged; the other is either charged or neutral. e. both balloons are charged- either with the same type or opposite type of charge
d. at least one balloon is charged; the other is either charged or neutral
An electrically charged atom (sometimes referred to as an ion) can be distinguished from an electrically neutral atom in that the charged atom (ion) Select one: a. either has a proton or an electron present somewhere within it. b. has lost one or more of its neutrons. c. does not have any neutrons. d. has an imbalance of protons and electrons (unequal numbers of these). e. has a different number of neutrons than the sum of its electrons and protons.
d. has an imbalance of protons and electrons (unequal numbers of these).
An electrically neutral atom is an atom which Select one: a. has a balance of protons, electrons, and neutrons (the same number of each). b. has a balance of neutrons and electrons (the same number of each). c. does not have any protons or electrons. d. has more neutrons than the sum of all its protons and electrons. e. has a balance of protons and electrons (the same number of each).
e. has a balance of protons and electrons (the same number of each).
________ are negatively charged and ________ are positively charged. As an object begins to gain or lose electrons from its atoms, it becomes positively or negatively charged. A negatively charged object has more ________ than ________. A positively charged object has more ________ than ________.
electrons, protons, electrons, protons, protons, electrons
The charged parts of the atom are the _________ and the _________. The _________ are positively charged and the _________ are negatively charged. The _________ are not charged and thus will not be of importance in this unit.
electrons, protons, protons, eletrons, neutrons.
Miss Chiff, the seventh grade science teacher, greets her students in an unusual manner. She stands at the door of her classroom, scuffing her feet back and forth on the carpet. As she does so, electrons move from the carpet to her shoes to her body. Miss Chiff is now charged with a ________ type of charge. Then, Miss Chiff reaches out and touches her students on the nose as they enter the classroom. As she does, some electrons leave Miss Chiff and move onto her students. Miss Chiff is now ________ negatively charged than before the contact with the student. And the student is now charged with a ________ type of charge.
negative, less, negative
