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3 years ago

The air in a car tire la compressed when the car rolls over a rock. If the air

Physics

1 answer:

stealth61 [152]3 years ago

8 0

Answer:

the signs of heat and work are; -Q and -W

Explanation:

The first law of thermodynamics is given by; ΔU = Q − W

where;

ΔU is the change in internal energy of a system,

Q is the net heat transfer (the sum of all heat transfer into and out of the system)

W is the net work done (the sum of all work done on or by the system).

Now, The system in this case is the tire and since the air gets warmer, heat must have left the system. Therefore Q is negative (-Q).

Since work is done by the system, W remains negative.

Thus, the signs of heat and work are; -Q and - W

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The equation for the speed of an electromagnetic wave is

igomit [66]

Answer:

c = 1 / √(ε₀*μ₀)

Explanation:

The speed of the electromagnetic wave in free space is given in terms of the permeability and the permittivity of free space by

c = 1 / √(ε₀*μ₀)

where the permeability of free space (μ₀) is a physical constant used often in electromagnetism and ε₀ is the permittivity of free space (a physical constant).

4 0

2 years ago

Two +1 C charges are separated by 30000 m, what is the magnitude of the force?

Kipish [7]

Answer:

The magnitude of the force is 10 N

Explanation:

Coulomb's Law

The electrostatic force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.

Written as a formula:

$\displaystyle F=k\frac{q_1q_2}{d^2}$

Where:

$k=9\cdot 10^9\ N.m^2/c^2$

q1, q2 = the objects' charge

d= The distance between the objects

We have two identical charges of q1=q2=1 c separated by d=30000 m, thus the magnitude of the force is:

$\displaystyle F=9\cdot 10^9\frac{1*1}{30000^2}$

F = 10 N

The magnitude of the force is 10 N

7 0

2 years ago

Vision is blurred if the head is vibrated at 29 Hz because the vibrations are resonant with the natural frequency of the eyeball

Likurg_2 [28]

Answer:

k = 4422.35 KN/m

Explanation:

Given that

Frequency ,f= 29 Hz

m = 7.5 g

Natural frequency ω

ω = 2 π f

We also know that for spring mass system

ω ² m =k

k=Spring constant

So we can say that

( 2 π f)² = m k

By putting the values

(2 x π x 29)² = 7.5 x 10⁻³ k

33167.69 = 7.5 x 10⁻³ k

k=4422.35 x 10³ N/m

k = 4422.35 KN/m

Therefore spring constant will be 4422.35 KN/m

4 0

3 years ago

The minimum frequency of light needed to eject electrons from a metal is called the threshold frequency, ν0. find the minimum en

shusha [124]

The energy carried by the incident light is
$E=hf$
where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
$E=hf=(6.63 \cdot 10^{-34}Js)(5.64 \cdot 10^{14}s^{-1})=3.74 \cdot 10^{-19}J$

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3 years ago

Which of the following rivers flows north in eastern Florida?

Zarrin [17]

St. John’s

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o0o0o0o0o0

6 0

2 years ago