Electric Lab4
Static Charge
Instructor:
Dr. Mohebi
Jiajie Huo(Jacky)
Member:
Ruihong Xiao
TEJ Shiwakoti
Anthony Hernandez
Dana Saiez
Rneiang Ye
WAJIH RAHMAN
2. introduction.
In this experiment, we are generally focusing on determining the
relatice effectiveness of various materials in transferring charge to
a pith ball.
1. F=kqq/r^2, while F refers to the electrical force, k refers to the
coefficient of the electricity force, q refers to the charge the
balls have.
2. G=mg, while G refers to the gravitational magnitude of the
object, m refers to the mass of it, while g refers to the
gravitational efficient.
3. Ne=Q/e, while Q refers to the charge of the object, e refers to
the charge of the electron.
3. Procedure.(additional: all temperature are in degree.)
a. Measure the mass of the pitch balls. M=0.1g.
b. we choose the silk and a robs, place a static electric charge on
them, and place the charge on the two balls.
c. Measure the distance the two balls repulsive effect.
D=1.6cm
e. repeat the above procedure using different materials.
3. Date sheets, spread sheets.
Rod
robber
plastic
robber
plastic
glass
plastic
Measured L(m) Date
Calculation
D(cm
Material
)
m(g) angle(o)
Q(c)
Ne
Microther
0
0.1 0.193
0
silk
1.6
0.1 0.193
4.8
1.10E-09
6.88E+09
silk
0
0.1 0.193
0
silk
1.2
0.1 0.193
3.6
7.00E-10
4.38E+09
microther
0
0.1 0.193
0
silk
0
0.1 0.193
0
Sample calculation:
tan/2=F/mg=d/2Lcos/2,mg=0.98kg*N,L=0.193m,d=0.016m,
=4.8o, F=kQQ/r^2
Q=sqrt[mgtan(/2)*r^2/k]=1.1e-9.
Ne=Q/e=1.1e-9/1.6e-19=6.875e+9
6. Discussion and conclusion.
In this experiment, we came across many problems, the first is
the rob can not get charged while mopping with the silk or any
kind of material except the plastic, so there are several kinds of
measure is missing. Secondly, when the plastic get charged, it is
hard to get the balls get charged and separate them by the electric
force, so we do it a lot more times. However, we successfully get
two set of answers and the angle of them is 4.8 o and 3.6o
separately, and the final Q is 1.1e-9 and 7.0e-10, the Ne would be
6.875e+9 and 4.375e+9, and we concluded that the magnitude of
the Ne is the same as that of the actual one, so we think it is
success in this rude experiment.