1) Current in the wire: 0.0875 A
The current in the wire is given by:

where
Q is the charge passing a given point in the conductor
t is the time elapsed
In this problem, we have
Q = 420 C is the total charge passing through a given point in a time of
t = 80 min = 4800 s
So, the current is

2) Drift velocity of the electrons: 
The drift velocity of the electrons in the wire is given by:

where
I = 0.0875 A is the current
is the number of free electrons per cubic meter
A is the cross-sectional area
is the charge of one electron
The radius of the wire is

So the cross-sectional area is

So, the drift velocity is

Answer:
7350 J
Explanation:
The gravitational potential energy of the rock sitting on the edge of the cliff is given by:

where
m is the mass of the rock
g is the gravitational acceleration
h is the height of the cliff
In this problem, we have
m = 50 kg
g = 9.8 m/s^2
h = 15 m
Substituting numbers into the formula, we find:

Because weight W = M g, the ratio of weights equals the ratio of masses.
(M_m g)/ (M_w g) = [ (p^2 Man )/ (2 K_man)] / [ (p^2 Woman )/ (2 K_woman)
but p's are equal, so
K_m/K_m = (M_w g)/(M_m g) = W_woman / W_man = 450/680 = 0.662
Answer:
A) having each person listen to just 1 song instead of 5.
Explanation:
Ravi could accurately use the outcome to compare the hearing capacities of his friends by this experiment if appropriate precautions are observed.
Playing 5 well known songs simultaneously could result to the interference of sounds when each participant moves away from the player. Which could naturally cause the variation in volume of the songs played with respect to the increasing distance.
Therefore, the reliability of the result from this experiment can be increased if each person listen to just 1 song instead of 5 at a predetermined volume. Each participant would be able to focus on hearing a song during the experiment.
The speed is 0.956 m / s.
<u>Explanation</u>:
The kinetic energy is equal to the product of half of an object's mass, and the square of the velocity.
K.E = 1/2
m

where K.E represents the kinetic energy,
m represents the mass,
v represents the velocity.
K.E = 1/2
m

1.10
10^42 = 1/2
3.26
10^31

= (1.10
10^42
2) / (3.26
10^31)
v = 0.956 m / s.