Answer:
Explanation:
Energy stored in a capacitor
= 1/2 C₁V²
capacity of a capacitor
c = εK A / d
k is dielectric and d is distance between plates .
When the distance between the plates is halved and then filled with a dielectric (κ = 4.3)
capacity becomes 4.3 x 2 times
New capacity
C₂ = 8.6 C₁
Energy of modified capacitor
1/2 C₂ V²= 1/2 x 8.6 c x V²
Energy becomes
8.6 times.
Energy stored = 8.6 x 10⁻⁴ J
Answer:
H / R = 2/3
Explanation:
Let's work this problem with the concepts of energy conservation. Let's start with point P, which we work as a particle.
Initial. Lowest point
Em₀ = K = 1/2 m v²
Final. In the sought height
= U = mg h
Energy is conserved
Em₀ =
½ m v² = m g h
v² = 2 gh
Now let's work with the tire that is a cylinder with the axis of rotation in its center of mass
Initial. Lower
Em₀ = K = ½ I w²
Final. Heights sought
Emf = U = m g R
Em₀ =
½ I w² = m g R
The moment of inertial of a cylinder is
I =
+ ½ m R²
I= ½
+ ½ m R²
Linear and rotational speed are related
v = w / R
w = v / R
We replace
½
w² + ½ m R² w² = m g R
moment of inertia of the center of mass
= ½ m R²
½ ½ m R² (v²/R²) + ½ m v² = m gR
m v² ( ¼ + ½ ) = m g R
v² = 4/3 g R
As they indicate that the linear velocity of the two points is equal, we equate the two equations
2 g H = 4/3 g R
H / R = 2/3
Answer:
Explanation:
An electromagnetic wave can be created by accelerating charges; moving charges back and forth will produce oscillating electric and magnetic fields, and these travel at the speed of light.
Answer:
C. Mg3N2
Explanation:
Magnesium has a positive 2 charge and nitrogen has a negative 3 charge. To completely balance it out, you need three magnesium’s and two nitrogen’s. The final charge for magnesium would be positive 6 and the final charge for nitrogen would be negative 6, this will make it neutral.