Answer:
1.87 A
Explanation:
τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s
d = diameter of copper wire = 2 mm = 2 x 10⁻³ m
Area of cross-section of copper wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
E = magnitude of electric field = 0.01 V/m
e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C
m = mass of electron = 9.1 x 10⁻³¹ kg
n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³
= magnitude of current
magnitude of current is given as
= 1.87 A
Answer:
Option E is correct 310N
Explanation:
Given that the force used to push the crate is F = 200N
The force directed 20° below the horizontal
Mass of crate is m = 25kg
Weight of the crate can be determine using
W = mg
g is gravitational constant =9.8m/s²
W = 25×9.8
W = 245 N
Check attachment. For free body diagram and better understanding
Using newton second law along the vertical axis since we want to find the normal force
ΣFy = m•ay
ay = 0, since the body is not moving in the vertical or y direction
N—W—F•Sin20 = 0
N = W+F•Sin20
N = 245+ 200Sin20
N = 245 + 68.4
N = 313.4 N
The normal force is approximately 310 N to the nearest ten
The Ozone layer is responsible for the absorption of harmful
radiation from the sun before it hits the surface or exterior structure of our
planet. It is known to be a belt of a known occurring gas, known as “ozone”
which is sealed around the Earth’s atmosphere. It serves as a shield, which absorbs
most of the sun’s ultraviolet radiation.
Answer:
Explanation:
It is given that,
A planar electromagnetic wave is propagating in the +x direction.The electric field at a certain point is, E = 0.082 V/m
We need to find the magnetic vector of the wave at the point P at that instant.
The relation between electric field and magnetic field is given by :
c is speed of light
B is magnetic field
So, the magnetic vector at point P at that instant is 
.
Pitch is the impression the listener gets of the <em>frequency</em> of the sound.
The speed of the sound is <em>not</em> related to its pitch/frequency.
If the speed and frequency were related, that would be a real problem. Bands, orchestras, and choirs could not exist ! All the instruments in the orchestra could play a note together, at the same time. But then the higher instruments ... the flute, trumpet, violins, high guitar strings and high piano keys ... would travel to you fast, and the lower instruments ... the trombone, tuba, double bass, bass drum, low guitar strings and the low piano keys ... would travel to you slow. They all played the note at the same time, but by the time you heard it, it would be all smeared out ... every instrument arriving at your ear at a different time !
