Complete Question
An isolated charged soap bubble of radius R0 = 7.45 cm is at a potential of V0=307.0 volts. V0=307.0 volts. If the bubble shrinks to a radius that is 19.0%19.0% of the initial radius, by how much does its electrostatic potential energy ????U change? Assume that the charge on the bubble is spread evenly over the surface, and that the total charge on the bubble r
Answer:
The difference is 
Explanation:
From the question we are told that
The radius of the soap bubble is 
The potential of the soap bubble is 
The new radius of the soap bubble is 
The initial electric potential is mathematically represented as
The final electric potential is mathematically represented as
The initial potential is mathematically represented as

The final potential is mathematically represented as

Now

substituting values

=> 
So
Therefore
where k is the coulomb's constant with value 
substituting values

Answer:
k_2 = 7.815 * 10^-3 s^-1
Explanation:
Given:
- rate constant of reaction k_1 = 7.8 * 10^-3 s^-1 @ T_1 = 25 C
- rate constant of reaction k_2 = ? @ T_2 = 75 C
- The activation energy E_a = 33.6 KJ/mol
- Gas constant R = 8.314472 KJ / mol . K
Find:
- rate of reaction k_2 @ T_2 = 75 C
Solution:
- we will use a combined form of Arrhenius equations that relates rate constants k as function of E_a and temperatures as follows:
k_2 = k_1 * e ^ [(E_a / R) * ( 1 / T_1 - 1 / T_2 )
- Evaluate k_2 = 7.8 * 10^-3* e^[(33.6 / 8.314472)*(1/298 -1/348)
- Hence, k_2 = 7.815 * 10^-3 s^-1
Answer:
Kinetic energy = 127.89 Joules
Explanation:
Kinetic energy is calculated using the following rule:
KE = (1/2)*v* v^2
Where:
m is the mass = 145 g = 0.145 kg
v is the velocity = 42 m/sec
Substitute in the above equation to get the kinetic energy as follows:
KE = (0.5)(0.145)(42)^2
Kinetic energy = 127.89 Joules
Hope this helps :)
Answer:
a) The force is zero, or the displacement is zero, or the angle is 180 degrees
b) The kinetic energy, speed, and velocity of the particle change.
c) W1 = - W2
Answer:

Explanation:
Knowing that the volume of a sphere is V=(4/3)πr³ and 
We must find
when r=14cm
V=(4/3)πr³ ⇒

and r=14cm then

Note: as you can see the relationship of change of r with respect to t is negative because it is a decrease, and also its volume ratio