I think it’s physical change, because the objects aren’t changing into another substance, just changing their physical shape. Hope this helps!
d thought i wouldnt trust me on it
Answer:
<em>The car will be moving at 5.48 m/s at the bottom of the hill</em>
Explanation:
<u>Principle of Conservation of Mechanical Energy</u>
In the absence of friction, the total mechanical energy is conserved. That means that
is constant, being U the potential energy and K the kinetic energy
U=mgh

When the car is at the top of the hill, its speed is 0, but its height h should be enough to produce the needed speed v down the hill.
The Kinetic energy is then, zero. When the car gets enough speed we assume it is achieved at ground level, so the potential energy runs out to zero but the Kinetic is at max. So the initial potential energy is transformed into kinetic energy.
We are given the initial potential energy U=45 J. It all is transformed to kinetic energy at the bottom of the hill, thus:

Multiplying by 2:

Dividing by m:

Taking square roots:



v = 5.48 m/s
The car will be moving at 5.48 m/s at the bottom of the hill
Answer:
he electron moves in the direction of a greater electric potential
Explanation:
Electric potential and electric field are related
V = -∫ E .ds
t
he electric force is related to the electric field
F = q E
F = q (-dV / ds)
since the electron has charge a = 1.6 1019 C
F = e dv / ds
therefore the electron moves in the direction of a greater electric potential
A) The electrons may jump to a higher energy level.