Answer:
C. Neutral
Explanation:
Ions will combine in a way that the overall ionic compound will always be neutral.
Mechanical energy (ME) is the sum of potential energy (PE) and kinetic energy (KE). When the toy falls, energy is converted from PE to KE, but by conservation of energy, ME (and therefore PE+KE) will remain the same.
Therefore, ME at 0.500 m is the same as ME at 0.830 m (the starting point). It's easier to calculate ME at the starting point because its just PE we need to worry about (but if we wanted to we could calculate the instantaneous PE and KE at 0.500 m too and add them to get the same answer).
At the start:
ME = PE = mgh
ME = 0.900 (9.8) (0.830)
ME = 7.32 J
Answer:
CO2 emissions from fossil fuel burning should be minimized at all cost. The CO2 are gotten when the carbons from hydrocarbons react with air(oxygen). This gas erodes the ozone layer which makes the melting of ice caps faster due to increased amount of heat radiations on the earth. This is the only best and permanent solution to the reduction of the amount of heat rays on the earth which is a global problem.
Objects which reflects back the sunrays could also be inserted into the sea to prevent the melting of the ice caps.
Answer:
(b) EAST
Explanation:
you can assume that the magnetic field points rightward, that is, in the positive x direction (NORTH). Furthermore, you can assume that the direction of the motion of the electron is in the positive y direction. Hence, you have:

You use the Lorentz formula to known which is the direction of the magnetic force over the electron:

which implies the cross product between the unitary vecors j and i, that is
(WEST)
However, the minus sign of the charge of the electron changes the direction 180°. Hence, the direction is k. That is, to the EAST
Answer:
a. 
b. 
c. 
Explanation:
First, look at the picture to understand the problem before to solve it.
a. d1 = 1.1 mm
Here, the point is located inside the cilinder, just between the wire and the inner layer of the conductor. Therefore, we only consider the wire's current to calculate the magnetic field as follows:
To solve the equations we have to convert all units to those of the international system. (mm→m)

μ0 is the constant of proportionality
μ0=4πX10^-7 N*s2/c^2
b. d2=3.6 mm
Here, the point is located in the surface of the cilinder. Therefore, we have to consider the current density of the conductor to calculate the magnetic field as follows:
J: current density
c: outer radius
b: inner radius
The cilinder's current is negative, as it goes on opposite direction than the wire's current.




c. d3=7.4 mm
Here, the point is located out of the cilinder. Therefore, we have to consider both, the conductor's current and the wire's current as follows:

As we see, the magnitud of the magnetic field is greater inside the conductor, because of the density of current and the material's nature.