Answer:
K = 2 10⁻⁸ J
Explanation:
Let's solve this exercise in parts, we start by finding the charge on each plate of the capacitor
C = Q / ΔV
C = ε₀ A / d
ε₀ A / d = Q / ΔV
Q = ε₀ A ΔV / d (1)
indicate the potential difference ΔV₁ = 12 V, the distance between the plates d₁ = 3 mm = 0.003 m,
as the power supply is disconnected and the capacitor is ideal the charge remains constant
in the second part we separate the plates at d₂ = 5 mm = 0.005 m, using equation 1
ΔV₂ =
we substitute the equation for Q
ΔV₂ =
ΔV₂ =
in the third part we use the concepts of energy
starting point. Test charge near positive plate
Em₀ = U = q ΔV₂
final point. Test charge near negative plate
Em_f = K
energy is conserved
Em₀ = Em_f
q ΔV₂ = K
K = q ΔV₁
we calculate
K = 1 10⁻⁹ 12 0.005/0.003
K = 2 10⁻⁸ J
Answer:
After 3 hours.
Explanation:
This is a encounter problem.
We start by writing the position equation of both objects.
We assume that acceleration is equal to zero in both boats ⇒ They move with constant speed
We put the origin of coordinates in the harbour so after 6 hours the first boat travels
The first boat will be 42 mi far from the harbour.
The position equation for a motion with acceleration equal to zero is :
Where is initial position
v is the speed
t is time and is initial time
Then is time variation
For the first boat :
Because we set
For the second one :
In the encounter : x1(t) = x2(t) ⇒
So after 3 hours they have the same position relative to the harbour
We can check by replacing the value t = 3h in both position equations
For x1(t) :
For x2(t) :
Answer:
Because this pole is different from the original pole that magnetized the paperclips, the top paperclip will become demagnetized in the opposite direction and the bottom paperclip will be repelled away
Answer:
Given:
Mass (m) = 75 kg
Height (h) = 10 m
Acceleration due to gravity (g) = 9.8 m/s²
To Find:
Potential Energy (PE)
Explanation:
The formula for potential energy due to gravity:
Substituting value of m, g & h in the formula: