Answer:
F = GMmx/[√(a² + x²)]³
Explanation:
The force dF on the mass element dm of the ring due to the sphere of mass, m at a distance L from the mass element is
dF = GmdM/L²
Since the ring is symmetrical, the vertical components of this force cancel out leaving the horizontal components to add.
So, the horizontal components add from two symmetrically opposite mass elements dM,
Thus, the horizontal component of the force is
dF' = dFcosФ where Ф is the angle between L and the x axis
dF' = GmdMcosФ/L²
L² = a² + x² where a = radius of ring and x = distance of axis of ring from sphere.
L = √(a² + x²)
cosФ = x/L
dF' = GmdMcosФ/L²
dF' = GmdMx/L³
dF' = GmdMx/[√(a² + x²)]³
Integrating both sides we have
∫dF' = ∫GmdMx/[√(a² + x²)]³
∫dF' = Gm∫dMx/[√(a² + x²)]³ ∫dM = M
F = GmMx/[√(a² + x²)]³
F = GMmx/[√(a² + x²)]³
So, the force due to the sphere of mass m is
F = GMmx/[√(a² + x²)]³
Answer:
t = 2.13 10-10 s
, d = 6.39 cm
Explanation:
For this exercise we use the definition of refractive index
n = c / v
Where n is the refraction index, c the speed of light and v the speed in the material medium.
The refractive indices of ice and crown glass are 1.13 and 1.52, respectively, therefore the speed of the beam in the material medium is
v = c / n
As the beam strikes perpendicularly, the beam path is equal to the distance of the leaves, there is no refraction, so we can use the uniform motion relationships
v = d / t
t = d / v
t = d n / c
Let's look for the times on each sheet
Ice
t₁ = 1.4 10⁻² 1.31 / 3 10⁸
t₁ = 0.6113 10⁻¹⁰ s
Crown glass (BK7)
t₂ = 3.0 10⁻² 1.52 / 3.0 10⁸
t₂ = 1.52 10⁻¹⁰ s
Time is a scalar therefore it is additive
t = t₁ + t₂
t = (0.6113 + 1.52) 10⁻¹⁰
t = 2.13 10-10 s
The distance traveled by this time in a vacuum would be
d = c t
d = 3 10⁸ 2.13 10⁻¹⁰
d = 6.39 10⁻² m
d = 6.39 cm
Greetings!
The correct answer choice is Choice 4.
<em>Why?</em>
In a scientific experiment the only thing being changed is the independent variable. Everything else should stay the same.
In this experiment, the independent variable is the amount of sunlight each plant should receive. <em>Here's a tip</em>- when looking for and independent variable look for whats being changed on purpose.
Hope this helps!
~Fluerie
Answer: 2. Solution A attains a higher temperature.
Explanation: Specific heat simply means, that amount of heat which is when supplied to a unit mass of a substance will raise its temperature by 1°C.
In the given situation we have equal masses of two solutions A & B, out of which A has lower specific heat which means that a unit mass of solution A requires lesser energy to raise its temperature by 1°C than the solution B.
Since, the masses of both the solutions are same and equal heat is supplied to both, the proportional condition will follow.
<em>We have a formula for such condition,</em>
.....................................(1)
where:
- = temperature difference
- c= specific heat of the body
<u>Proving mathematically:</u>
<em>According to the given conditions</em>
- we have equal masses of two solutions A & B, i.e.
- equal heat is supplied to both the solutions, i.e.
- specific heat of solution A,
- specific heat of solution B,
- & are the change in temperatures of the respective solutions.
Now, putting the above values
Which proves that solution A attains a higher temperature than solution B.
The answer is: 120V
Power is the rate at which energy is supplied/transformed in time:
we can write:
V ddp in Volts represents Energy/Charge i.e. energy carried by each coulomb;
I current in Amperes represents Charge/time or coulombs passing each seconds.
combining them we have:
Power = energy/time = V • 1
or
1200 = V ⋅ 10
V = 1200/10 = 120V