Explanation:
When a bullet is fired from a rifle, the actual firing makes a distinctive sound, but people at a distance may hear a second because the bullet creates a shock wave , a little sonic boom( speed of this sonic boom is greater than the speed of sound). It is this sound only that is heard by the people at a distance from the gun.
Answer:
Explanation:
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Answer:
Atoms can be joined together by chemical bonds.
Explanation:
When atoms form bonds, they can achieve a stable electron arrangement. To achieve a stable electron arrangement atoms can lose, gain or share electrons. There are many different types of bonds that hold atoms together.
Answer:
Explanation:
Number of turns
N = 210turns
Length of solenoid
l = 0.18m
Cross sectional area
A = 4cm² = 4 × 10^-4m²
A. Inductance L?
Inductance can be determined using
L = N²μA/l
Where
μ is a constant of permeability of the core
μ = 4π × 10^-7 Tm/A
A is cross sectional area
l is length of coil
L is inductance
Therefore
L = N²μA / l
L=210² × 4π × 10^-7 × 4 × 10^-4 / 0.18
L = 1.23 × 10^-4 H
L = 0.123 mH
B. Self induce EMF ε?
EMF is given as
ε = -Ldi/dt
Since rate of decrease of current is 120 A/s
Then, di/dt = —120A/s, since the current is decreasing
Then,
ε = -Ldi/dt
ε = - 1.23 × 10^-4 × -120
ε = 0.01478 V
ε ≈ 0.015 V
<span>b. It ensures that measurements are taken from two points
that are very far apart.
Measurements taken six months apart are the farthest apart
that an astronomer can ever get ... they're on opposite sides
of the Earth's orbit !</span>
