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3 years ago

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What is Newton's second law of motion

1 answer:

Alexandra [31]3 years ago

8 0

Newton’s second law is that the acceleration of an object is directly related to the net force and inversely related to its mass. Acceleration of an object depends on two things, force and mass.

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T=2π√(l/g) is dimensionally correct

Rasek [7]

Yes it is. Both sides have the dimensions of [time].

3 0

4 years ago

jim halves the distance between himself and a sound source. What is the change of decibels of the sound he hears?

steposvetlana [31]

Answer:

6.02dB

Explanation:

The sound level intensity can be calculated by using the formula:

$I(dB)=10log_{10}(\frac{I}{I_o})$

where Io is the threshold of human hearing, and I is the intensity of the sound in at a certain distance. I is given by

$I=\frac{P}{4\pi r^2}$

where P is the power of the source and r is the distance to the source. By replacing I in the expression for I(dB) we obtain

$I(dB)=10log(\frac{P}{4\pi r^2I_o})=10log(\frac{P}{\pi r^2I_o})-10log(4)$

when jim halves the distance we have r'=1/2r:

$I'(dB)=10log(\frac{P}{4\pi (\frac{1}{2}r)^2I_o})=10log(\frac{P}{\pi r^2I_o})$

Hence, the change o decibels is:

$I'-I=10log(4)=6.02dB$

hope this helps!!

4 0

3 years ago

It is known that water applies some pressure on a container; does water do any work in this case?

julsineya [31]

Not unless it crushes the container. Work is force acting through a distance. As long as nothing moves, no work is done.

5 0

4 years ago

Help needed for science homework

Gemiola [76]

The answer is 1/2 * base * height

8 0

3 years ago

Compute the dot product of the vectors u and v, and find the angle between the vectors. Bold v equals 7 Bold i minus Bold j and

OLga [1]

Answer:

$\theta = 106.3 degree$

Explanation:

As we know that

$\vec w = -\hat i + 7\hat j$

$\vec v = 7\hat i - \hat j$

also we know that

$\vec v. \vec w = -14$

it is given as

$\vec v. \vec w = (-\hat i + 7\hat j).(7\hat i - \hat j)$

$\vec v. \vec w = - 7 - 7 = -14$

also we can find the magnitude of two vectors as

$|v| = \sqrt{(-1)^2 + (7)^2}$

$|v| = \sqrt{50}$

similarly we have

$|w| = \sqrt{(7^2) + (-1)^2}$

$|w| = \sqrt{50}$

now we know the formula of dot product as

$\vec v. \vec w = |v||w| cos\theta$

$-14 = (\sqrt{50})^2cos\theta$

$\theta = cos^{-1}(\frac{-14}{50})$

$\theta = 106.3 degree$

3 0

3 years ago