Answer:

Explanation:
Assuming the light takes essentially no time to reach you, the distance at which the lightning occurred can be calculated by multiplying the speed of sound by the time it takes to hear the thunder:

Answer:
C. 0.25J
Explanation:
Energy stored in the magnetic field of the inductor is expressed as E = 1/2LI² where;
L is the inductance
I is the current flowing in the inductor
Given parameters
L = 20mH = 20×10^-3H
I = 5A
Required
Energy stored in the magnetic field.
E = 1/2 × 20×10^-3 × 5²
E = 1/2 × 20×10^-3 × 25
E = 10×10^-3 × 25
E = 0.01 × 25
E = 0.25Joules.
Hence the energy stored in the magnetic field of this inductor is 0.25Joules
Answer: The speed necessary for the electron to have this energy is 466462 m/s
Explanation:
Kinetic energy is the energy posessed by an object by virtue of its motion.

K.E= kinetic energy = 
m= mass of an electron = 
v= velocity of object = ?
Putting in the values in the equation:


The speed necessary for the electron to have this energy is 466462 m/s
Answer:
1.05m or 105cm
Explanation:
Using the hooke's law equation as follows;
F = –k.x
Where;
F = force (N)
x = extension length (m)
k = constant of proportionality (N/m)
According to the information given in this question;
Displacement (x) = 85cm = 85/100 = 0.85m
Force = 12500N
Using F = kx, we find the proportionality constant
k = F/x
K = 12500/0.85
K = 14705.8N/m.
Also, since K = 14705.8N/m, the displacement (x), when the force increases to 15500N is;
F = kx
x = F/k
x = 15500/14705.8
x = 1.05m or 105cm