Answer:
Thermal energy of an isolated system changes with time If the mechanical energy of that system is constant according to the first law of thermodynamics, which states that thermal energy of an isolated system can still change as long as the total energy of that system does not change.
Explanation:
Answer:
Five Characteristics of a Mineral
Minerals Are Natural. You must find minerals in nature; substances concocted in laboratories don't qualify. ...
Minerals Are Inorganic. ...
Minerals Are Solids. ...
Definite Chemical Composition. ...
Crystalline Structure.
These are just some examples.
Explanation:
to be franc i really think the answer is B
Answer:
Hans Christian Oersted began a new scientific epoch when he discovered that electricity and magnetism are linked. He showed by experiment that an electric current flowing through a wire could move a nearby magnet. The discovery of electromagnetism set the stage for the eventual development of our modern technology-based world.
Explanation:
Answer:
The shortest braking distance is 35.8 m
Explanation:
To solve this problem we must use Newton's second law applied to the boxes, on the vertical axis we have the norm up and the weight vertically down
On the horizontal axis we fear the force of friction (fr) that opposes the movement and acceleration of the train, write the equation for each axis
Y axis
N- W = 0
N = W = mg
X axis
-Fr = m a
-μ N = m a
-μ mg = ma
a = μ g
a = - 0.32 9.8
a = - 3.14 m/s²
We calculate the distance using the kinematics equations
Vf² = Vo² + 2 a x
x = (Vf² - Vo²) / 2 a
When the train stops the speed is zero (Vf = 0)
Vo = 54 km/h (1000m/1km) (1 h/3600s)= 15 m/s
x = ( 0 - 15²) / 2 (-3.14)
x= 35.8 m
The shortest braking distance is 35.8 m
