When the surface of the comb rubs on your hair, the comb is electrically charged. When the comb comes close to the paper, the charge on the comb causes charge separation on the paper bits. Since paper is neutral, positive and negative charges are equivalent. The charge on the comb charges the area of the bit of paper nearest the comb to the opposite. Thus, the bits of paper become attracted to the comb.
Answer:
E = 31.329 N/C.
Explanation:
The differential electric field at the center of curvature of the arc is
<em>(we have a cosine because vertical components cancel, leaving only horizontal cosine components of E. )</em>
where is the radius of curvature.
Now
,
where is the charge per unit length, and it has the value
Thus, the electric field at the center of the curvature of the arc is:
Now, we find and . To do this we ask ourselves what fraction is the arc length 3.0 of the circumference of the circle:
and this is
radians.
Therefore,
evaluating the integral, and putting in the numerical values we get:
Answer:
temperature measures heat - the unit is Celsius - and it is measured with a thermometer.
length is measuring how long, tall, or wide something is - the base unit it metres - and it is measured with a ruler or a metre stick
volume is measuring the quantity of a three dimensional space - the unit is cubic centimetre - you find volume by taking the measurements with a ruler
mass is measuring how much space something takes up/ weight - unit is the gram - you use a scale
Answer:
149 m
Explanation:
The distances across the lake is forming a triangle.
let the distance between the point and the left side be 'x'
and the distance between the point and the right be 'y'
and the distance across the lake be 'z' and the angle opposite to 'z' be 'Z' given:
∠Z = 83°
x = 105 m
y = 119 m
Now, applying the Law of Cosines, we get
z² = x² + y² - 2xycos(Z)
Substituting the values in the above equation, we get
z² = 105² + 119² - 2×105×119×cos(83°)
or
z = √22140.48
or
z = 148.796 m ≈ 149 m
The point is 149 m across the lake
Answer:
n = 1.4266
Explanation:
Given that:
refractive index of crystalline slab n = 1.665
let refractive index of fluid is n.
angle of incidence θ₁ = 37.0°
Critical angle
According to Snell's law of refraction:
At point P ;
Therefore:
Then maximum value of refractive index n of the fluid is:
n = 1.4266