False, chemical change in baking a cake does not change color. There are other properties involved besides color change like the fluffiness of the cake and the taste of the cake.
Some chemical changes cause color changes but not always
B. force, distance, and time
Take a look at the definition of a Joule (SI unit of work) and the definition of a Watt (SI unit of power). They're (kg*m^2)/s^2 for work and (kg*m^2)/s^3 for power. Another definition for work is Newton Meter which is force times distance, and since you can define work as force times distance, then power is work per second. So it looks like you need force and distance to calculate work, and then time since power is work over time. So of the 4 choices, we've been given, let's see if any of them allow us to calculate both work and power.
<span>
a. energy, force, and time
* OK. Force will get us Newtons. But how much work do you have, don't know. Since work is force times distance. So can't get work. And without getting work, can't get power. Wrong answer.
b. force, distance, and time
* Force over distance nicely defines work. And time is essential since power is work over time. So this looks to be very good choice.
c. force, mass, and distance
* Have a problem here. Time is pretty essential since all of the SI units for work and power have seconds hiding somewhere in their definition. So this is the wrong answer.
d. mass, force, and energy
* Same issue, no time element here. So wrong answer.
</span>
I believe the two ways to increase an object’s potential energy, is either by an object’s placement or by an object moving up a gradient. So the higher the object is according to its initial height, the higher the potential energy. And when an object is at a constant velocity moving up a hill, the gravitational potential is increasing, while the kinetic energy is decreasing.
You have two different phases of the star: 1 the Sun-like phase and 2 the neutron star phase. The given quantities are:
r₁ = r(Sun) = 695700km
m₁ = 8 Msun
f₁ = 1 rev / 12 days
m₂ =

·m₁
First thing, you need to transform the frequency in units of revolution/seconds
f₁ = 1 rev / (12·24·60·60) = 1 rev / 1036800 s
and then into angular velocity through the formula
ω₁ = 2πf = 6.06E-6 rad/s
a) If the angular momentum stays the same: L₁ = L₂
where L = I·ω
and the momentum of inertia I is given by I = m·r²
Therefore, substituting we have:
m₁·r₁²·ω₁ = m₂·r₂²·ω₂
And we can find:
ω₂ = <span>

</span>
(remember m₂=

·m₁ so we can cancel out the two m₁)
We obtain:
ω₂ = (<span>695700²·6.06E-6)/(0.25·12²) = 81473.1 rad/s
we can transform it back into frequency:
</span>f₂ = ω₂/2<span>π = 1 rev / 12967 s = 7.7e-5 rev/s
b) If L</span>₂ =

·L₁
we do expect an angular velocity 4 times smaller.
Using the same formulas as above:

·m₁·r₁²·ω₁ =

·m₁·r₂²·ω₂
ω₂ = <span>

=
= </span><span>[(695700²·6.06E-6)(12²) = 20368 rad/s
</span>and
f₂ = 1 rev / 3242 s = 3.08e-4 rev/s