The electric force on the electron is opposite in direction to the electric field E. E points in the -y direction, so the electric force will point in the +y direction. The magnitude of the electric force is given by:
F = Eq
F = electric force, E = electric field strength, q = electron charge
We need to set up a magnetic field such that the magnetic force on the electron balances out the electric force. Since the electric force points in the +y direction, we need the magnetic force to point in the -y direction. Using the reversed right hand rule, the magnetic field must point in the -z direction for this to happen. Since the direction is perpendicular to the +x direction of the electron's velocity, the magnetic force is given by:
F = qvB
F = magnetic force, q = charge, v = velocity, B = magnetic field strength
The electric force must equal the magnetic force.
Eq = qvB
Do some algebra to isolate B:
E = vB
B = E/v
Let's solve for the electron's velocity. Its kinetic energy is given by:
KE = 0.5mv²
KE = kinetic energy, m = mass, v = velocity
Given values:
KE = 2.9keV = 4.6×10⁻¹⁶J
m = 9.1×10⁻³¹kg
Plug in and solve for v:
4.6×10⁻¹⁶ = 0.5(9.1×10⁻³¹)v²
v = 3.2×10⁷m/s
B = E/v
Given values:
E = 7500V/m
v = 3.2×10⁷m/s
Plug in and solve for B:
B = 7500/3.2×10⁷
B = 0.00023T
B = 0.23mT
Answer:
Explanation:
I'm not sure you can do this without just a bit more information. I can tell you what the mass of the water is when the rocks are removed. When we know that, we know the volume of the water that was displaced. whether or not this is enough information to determine the volume of the box, I'm not sure.
400 grams raises the box 1 cm.
The density of water = 1 gm / cm^3
400 grams of water = 400 mL or 400 cm^3
The volume of the displaced water = 400 cm^3
The volume a slice from the square prism is B*h
B = 400 cm^2
h = 1 cm
If the base is 400 cm^2 then each side is
s^2 = 400
sqrt(s^2)= sqrt(400)
s = 20
The volume of the box is 20^3 = 8000 cm^3
Answer:
<em>The distance the car traveled is 21.45 m</em>
Explanation:
<u>Motion With Constant Acceleration
</u>
It occurs when an object changes its velocity at the same rate thus the acceleration is constant.
The relation between the initial and final speeds is:
![v_f=v_o+at\qquad\qquad [1]](https://tex.z-dn.net/?f=v_f%3Dv_o%2Bat%5Cqquad%5Cqquad%20%5B1%5D)
Where:
a = acceleration
vo = initial speed
vf = final speed
t = time
The distance traveled by the object is given by:
![\displaystyle x=v_o.t+\frac{a.t^2}{2}\qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3Dv_o.t%2B%5Cfrac%7Ba.t%5E2%7D%7B2%7D%5Cqquad%5Cqquad%20%5B2%5D)
Solving [1] for a:
Substituting the given data vo=0, vf=6.6 m/s, t=6.5 s:
The distance is now calculated with [2]:
x = 21.45 m
The distance the car traveled is 21.45 m
Answer: metals.
Justification:
There are 118 elements which you can find in the periodic table ordered by atomic number. Those elements my be classified into metals, non-metals and metalloids.
The metals are placed on the left side of the periodic table. The metals share the properties of luster, conductivity and flexibility.
The properties of non-metals (which are on the right side of the periodic table) are opposite to those of metals: opaque, low conductivity and brittle.
Metalloids have in between properties.
Copper, for example is a metal: it has luster, is flexible and is highly conductive of the electricity (and temperature).
