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3 years ago

When is a body said to be at res

Physics

1 answer:

Aleksandr [31]3 years ago

7 0

When there is no motion a body is at rest

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A bag of rocks has a mass of 16.4 kg what is it weight here on the earth

Alex73 [517]

Answer
160,72N
Explanation
W=mg
=(16.4)(9.8)

6 0

1 year ago

The Coulomb force between two charges q1 and q2 at separation r in air is F. If half of the separation is filled with medium of

vodomira [7]

Answer:

The new Coulomb force is q₁q₂/9πε₀r²

Explanation

The coulomb force between the two charges q₁ and q₂ at a distance r in air is given by F = q₁q₂/4πε₀r².

Now, let us assume the material of dielectric constant κ = 9 is placed between them on the side of the q₁ charge. The value of its effective charge is now q₃ = q₁/κ at a distance of d = r/2 from the q₂ charge.

Since we have air between q₂ and q₃, the coulomb force between them is

F' = q₂q₃/4πε₀d²

= q₂(q₁/κ)/4πε₀(r/2)²

= 4q₂q₁/κ4πε₀r²

= 4/κ(q₂q₁/4πε₀r²)

= 4/9 × (q₂q₁/4πε₀r²)

= q₁q₂/9πε₀r²

So, the new Coulomb force is q₁q₂/9πε₀r²

3 0

3 years ago

A train starting from rest picks up a speed of 20 m/s in 20 s while travelling on a straight path. It continues to move at the s

Andrej [43]

Answer:

$1300 m$

Explanation:

As the path is straight, so the speed is equivalent to velocity. Now. assuming that the acceleration and deceleration of the train are constant. So, change of velocity with respect to time for acceleration as well as deceleration is constant. Hence, the slope of the speed-time graph is constant for the time of acceleration as well as deceleration. The speed for the time from $20 s$ to $70 s$ is constant, so slope for this interval of time is zero. The speed-time graph is shown in the figure.

The total distance covered by the train during the entire journey is the area of the speed-time graph.

Area $=\frac{1}{2}(20\times 20)+ 50\times 20+\frac{1}{2}(20\times 10)$

$=200+1000+100$

$=1300$

As velocity is in $m/s$ and time is in $s$ so the unit of area is $m$

Hence, the total distance is $1300m$ .

8 0

2 years ago

A violin string that is 50.0 cm long has a fundamental frequency of 440 Hz. What is the

amid [387]

For a standing wave on a string, the wavelength is equal to twice the length of the string:
$\lambda=2 L$
In our problem, L=50.0 cm=0.50 m, therefore the wavelength of the wave is
$\lambda = 2 \cdot 0.50 m = 1.00 m$

And the speed of the wave is given by the product between the frequency and the wavelength of the wave:
$v=\lambda f = (1.00 m)(440 Hz)=440 m/s$

5 0

3 years ago

Read 2 more answers

Which statement provides the most complete description of an object's motion?

vivado [14]

Answer:

A. The bird watcher followed the south trail a distance of five kilometers in 45 minutes.

5 0

2 years ago