Scientists can tell this by looking at seismic waves released by earthquakes. ( if you need me to elaborate more ask)
I hope this helps. it was right when i took the test.
Answer:
E=12.2V/m
Explanation:
To solve this problem we must address the concepts of drift velocity. A drift velocity is the average velocity attained by charged particles, such as electrons, in a material due to an electric field.
The equation is given by,

Where,
V= Drift Velocity
I= Flow of current
n= number of electrons
q = charge of electron
A = cross-section area.
For this problem we know that there is a rate of 1.8*10^{18} electrons per second, that is



Mobility
We can find the drift velocity replacing,


The electric field is given by,



Answer:
Total energy is constant
Explanation:
The laws of thermodynamics state that thermal energy (heat) is always transferred from a hot body (higher temperature) to a cold body (lower temperature).
This is because in a hot body, the molecules on average have more kinetic energy (they move faster), so by colliding with the molecules of the cold body, they transfer part of their energy to them. So, the temperature of the hot body decreases, while the temperature of the cold body increases.
This process ends when the two bodies reach the same temperature: we talk about thermal equilibrium.
In this problem therefore, this means that the thermal energy is transferred from the hot water to the cold water.
However, the law of conservation of energy states that the total energy of an isolated system is constant: therefore here, if we consider the hot water + cold water as an isolated system (no exchange of energy with the surroundings), this means that their total energy remains constant.
Explanation:
It is given that,
Displacement of the delivery truck,
(due east)
Then the truck moves,
(due south)
Let d is the magnitude of the truck’s displacement from the warehouse. The net displacement is given by :


d = 4.03 km
Let
is the direction of the truck’s displacement from the warehouse from south of east.


So, the magnitude and direction of the truck’s displacement from the warehouse is 4.03 km, 37.4° south of east.