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3 years ago

PLEASE HELP!!!! ): PLEASE!!!

Physics

1 answer:

amid [387]3 years ago

6 0

Answer:

Because the person is changing direction

Explanation:

The acceleration of an object is defined as the rate of change of velocity:

$a=\frac{\Delta v}{\Delta t}$

where

$\Delta v$ is the change in velocity

$\Delta t$ is the change in time

We must keep in mind that velocity is a vector, consisting of a speed and a direction. Therefore, a change in velocity means:

- either a change in the speed of the object, or

- a change in its direction

In this problem, the person is running around the track with a constant speed. However, his velocity is constantly changing (because the track is circular), this means that the change in velocity is not zero, and so there is a non-zero acceleration.

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What color is mercury

Evgen [1.6K]

Hello!
If you are referring to the mercury substance, mercury is a bright red color, usually used in early thermometers and is deadly if humans have a lot of constant with this substance

7 0

3 years ago

Read 2 more answers

A magnetic field of 0.080 T is in the y-direction. The velocity of wire segment S has a magnitude of 78 m/s and components of 18

Annette [7]

Answer:

Part a)

Induced EMF when length vector is along Z direction is 0.72 V

Part b)

Induced EMF when length vector is along Y direction is ZERO

Explanation:

As we know that the motional EMF induced in the wire is given as

$E = (v\times B). L$

As we know that

$v = 18\hat i + 24\hat j + 72\hat k$

$B = 0.080 \hat j$

$L = 0.50 \hat k$

now we have

$\vec v \times \vec B = 1.44\hat k - 5.76 \hat i$

so we have

$E = 1.44 (0.50) = 0.72 V$

If the length vector is along Y direction then we have

$L = 0.50 \hat j$

so again we have

$\vec v \times \vec B = 1.44\hat k - 5.76 \hat i$

so we have

EMF = 0

6 0

3 years ago

In musical language, mezzo forte (mf) signals that the music's volume should be

jeka57 [31]

It is medium loud because very loud is called forte.
mezzo means medium. forte means loud. mezzo forte means medium loud.

answer: d) medium loud

8 0

3 years ago

What is the advantage of SI unit over CGS unit?

Allushta [10]

ADVANTAGE

PEOPLE USED CERTAIN UNIT OF MEASUREMENT IN THEIR SPECIFIC REGION WHICH IS NOT ACCEPTED BY WORLD IN CGS SYSTEM.CGS UNIT MADE

DIFFICULTY IN TRADE. LATER SI UNIT OF MEASUREMENT HAVE BEEN ADOPTED IN 1960 AD TO BRING THE uniformity IN measurement throughout THE WORLD. SI SYSTEM MADE THE MEASURENT AROUND WORLD MORE EFFECTIVE AND LESS COFUSING THAN CGS UNIT.

5 0

3 years ago

What is the rotational kinetic energy of the Earth about the Sun? Assume the earth is a uniform sphere, mass of the Earth is 5.9

Thepotemich [5.8K]

Answer:

2.66x10^33 J

Explanation:

In order to do this, we first need to know the expression for kinetic energy:

E = 1/2 I*w² (1)

I is moment of innertia

w is angular speed.

Moment of Innertia can be calculated using the following expression:

I = 2/5 M*R² (2)

M is mass of earth, R is radius of earth

Replacing the data in expression (2) we have:

I = 2/5 * 5.97x10^24 * (6.37x10^6)²

I = 9.69x10^37 kg m²

Next, we need to calculate the angular speed of Earth over it's axis, this is easy, because we know the Earth rotates over it's own axis once a day, 24 hours (86400 s), and assuming Earth is a perfect sphere, we can calculate the speed:

w = 2π / 86400 = 7.27x10^-5 rad/s

next thing we need to do is calculate the rotational kinetic energy of earth on it's axis, using equation (1) so:

E = 1/2 * 9.69x10^37 * (7.27x10^-5)²

E = 2.56x10^29 J

Now that we have this value, we can finally calculate the rotational kinetic energy of earth about the sun. For that, we need to calculate again the angular speed of earth about the sun. The Earth rotates around the sun once a year, or 365 days, which is 3.1536x10^7 s, so the angular speed would be:

w = 2π/3.1536x10^7 = 1.99x10^-7 rad/s

finally the energy is the combination of the sun and earth so:

K = 1/2 (Ie + Me*Rorb²)wo²

I is innertia for earth

Me mass of earth

Rorb RAdius of orbit around the sun

wo is angular speed around the sun

Replacing the data we finally have:

K = 1/2 [9.69x10^37 + 5.97x10^24 * (1.5x10^11)²]*(1.99x10^-7)²

K = 2.66x10^33 J

4 0

3 years ago