The release of free energy drives the spontaneous reaction.
Spontaneity can be <span>determined
using the change in </span>Gibbs free energy
(the thermodynamic potencial):
delta G=delta H – T*delta
S
where delta H is the enthalpy and delta S is the entropy.
The direction (the sign) of delta G depends of the changes
of enthalpy and entropy. If delta G is negative then the process is
spontaneous.
In our case, both delta H and delta S are negative values, the
process as said is spontaneous which means that it may proceed in the forward
direction.
When light travels from a medium with higher refractive index to a medium with lower refractive index, there is a critical angle after which all the light is reflected (so, there is no refraction).
The value of this critical angle can be derived by Snell's law, and it is equal to

where n2 is the refractive index of the second medium and n1 is the refractive index of the first medium.
In our problem, n1=1.47 and n2=1.33, so the critical angle is
Answer:

Explanation:
m = Mass of roller coaster = 2000 kg
r = Radius of loop = 24 m
v = Velocity of roller coaster = 18 m/s
g = Acceleration due to gravity = 
Normal force at the point will be

The force exerted on the track is
.
The intensity of a sound wave is defined as the amount of energy passing through a unit area of the wave front in unit of time.
Answer:
See answers below
Explanation:
a.
F = mg,
15.5 N = m(9.8 m/s²)
m = 1.58 kg
b.
Fnet = Applied force - resistance,
Fnet = 18 N - 4.30 N,
Fnet = 13.70 N
Fnet = ma
13.70 N = (1.58 kg)a
a = 8.67 m/s²
For the free body diagram, draw a box with an upward arrow labeled 15.5 N, a downward label labeled 15.5 N, a right label labeled 18 N, and a left label labeled 4.30 N.