Answer:
a) I = 1,894 10¹⁰ W / m², b) E = 1.376 10⁵ N / C
Explanation:
a) intensity is defined as energy per unit area per unit time
I = P / A
let's reduce the magnitudes to the SI system
P = 10 mW = 10 10⁻³ W
d = 0.82 μm = 0.82 10⁻⁶ m
the laser area is
A =π r² = π d²/4
A =π (0.82 10⁻⁶)²/4
A = 5.28 10⁻¹³ m²
we calculate
I =
I = 1,894 10¹⁰ W / m²
b) average intensity and electric field are related
I = E * E
E = √I
E =
E = 1.376 10⁵ N / C
Answer:
The magnitude of an earthquake is 5.6.
Explanation:
The magnitude of an earthquake can be found as follows:

Where:
I: is the intensity of the earthquake = 37.25 cm
S: is the intensity of a standard earthquake = 10⁻⁴ cm
Hence, the magnitude is:

Therefore, the magnitude of an earthquake is 5.6.
I hope it helps you!
When a balloon is rubbed with a wool cloth, e<span>lectrons move from the atoms in the balloon to the atoms in the cloth, causing the cloth to have a negative charge. Therefore, the answer is B. Before they were rubbed together, they both had balanced charges. However, after rubbing them, the wool is left with the positive charge, and the balloon with the negative. This causes the atoms in the cloth to flow to the balloon, leaving the cloth with a negative charge.</span>
Required Heat = Q
Q = Mass * specific heat of water * change in temp.
Q = 5g * 1g/cal*degC * 20degC
Q = 100 cal of heat is required
To convert calories to Joules,
1 cal = 4.184 Joules
100cal = 418.4 J of heat is needed