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3 years ago

Please help! This is due in 10 minutes!! I will mark brainliest asap

Physics

2 answers:

SashulF [63]3 years ago

7 0

The object is at rest. This is because time is going by and there’s no distance being added

Dominik [7]3 years ago

6 0

Third option is the answer aka the object is resting hope this helps you

You might be interested in

When would the velocity of a wave traveling in a medium change?

creativ13 [48]

When its going from one medium to another.

5 0

3 years ago

What is the difference between the number of electrons in an atom of selenium,se, and the number of electrons in an atom of alum

Daniel [21]

Selenium has 36 electrons34(atomic number) + 2(amount of electrons gained in the <span>ion, has a 2- charge) = 36
</span>To identify the number of electrons an element has, all you need is a periodic table. Identify the atomic number (the smallest of the 2 numbers in the box). That number will be the number of protons which is also the number of electrons.
*number Atoms of all elements are made up of three primary particles: protons, neutrons, and electrons. The "sub-atomic" particles each have specific properties that such as size, electrical charge, etc. that are crucial for the stability of the atom. The particles break down like this: Particle Relative size Charge Location How to determine

Proton 1 + in the nucleus # of protons= element's atomic # (use periodic table)

Electron 0 - outside nucleus # of electrons=# of protons(in neutral, "normal" atom)

Neutron 1 0 in the nucleus Must be told or given (ie. can vary--isotopes--

for small elements most common form often

consists of isotope where #protons=#neutrons) Aluminum has 13 electrons because it needs 13 negative charges to balance the 13 postively-charged protons (which is what the periodic table told us it contains). This will make the Aluminum atom electrically neutral.

5 0

3 years ago

A 45.8-kg girl is standing on a 151-kg plank. Both originally at rest on a frozen lake that constitutes a frictionless, flat sur

erik [133]

Answer:

a. 1.12m/s

b. 0.34m/s

Explanation:

Let Vgi = the velocity of the girl relative to the ice

Let Vgp = the velocity of the girl relative to the plank

Let Vpi = the velocity of the plank relative to the ice

Vgi = Vgp + Vpi

From the question, Vgp = 1.46/s

So, Vgi = 1.46 + Vpi

Conservation of Momentum (Relative to the ice), we have

Initial Momentum = Final Momentum

Because the girl and the plank are at rest initially, the initial Momentum = 0

So, 0 = Mg * Vgi + Mp * Vpi

Where Mg = Mass of the girl = 45.8kg

Mo = Mass of the Plank = 151kg

Make Vpi the subject of the formula, we then have

-Mg*Vgi = Mp*Vpi ---------- Divide through by Mp

Vpi = -Mg * Vgi/Mp

Vpi =( -45.8 * Vgi)/151

Vpi = -45.8Vgi/151

Remember that, we have (Vgi = 1.46 + Vpi)

We then substitute the expression of Vpi in the above equation

That is;

Vgi = 1.46 + (-45.8Vgi/151) ------- Open the bracket

Vgi = 1.46 - 45.8Vgi/151 ----------- Multiply through by 151

151 * Vgi = 151 * 1.46 - 45.8Vgj

151Vgi = 220.46 - 45.8Vgi --------- Collect like terms

151Vgi + 45.8Vgi = 220.46

196.8Vgi = 220.46 --------------- Divide through by 196.8

Vgi = 220.46/196.6

Vgi = 1.1213631739572736

Vgi = 1.12 m/s (Approximated)

So, the velocity of the girl relative to the ice is 1.12m/s

b. Velocity of the plank, relative to the ice

We can solve this using (Vgi = 1.46 + Vpi)

All we need to do is substitute 1.12 for Vgi in the equation

So, we have

Vgi = 1.46 + Vpi becomes

1.12 = 1.46 + Vpi -------- Collect like terms

1.12 - 1.46 = Vpi

-0.34 = Vpi

So, the Velocity of the plank is 0.34m/s to the left

3 0

4 years ago

Read 2 more answers

A ball is throw into the sky at 18m/s. How high can it reach?

Komok [63]

Answer:

The maximum height of the ball will be "16.53 m".

Explanation:

Given that,

$V_{final} = 18 \ m/s$

As we know,

The initial as well the final height on the ball will be same after it reaches it's maximum height.

then,

⇒ $V_{final}=V_{initial}$

where, $V_{initial} = \sqrt{2gh}$

$=\sqrt{2\times 9.8\times h}$

$=\sqrt{19.6h}$

hence,

The max height of the ball will be:

⇒ $18=\sqrt{19.6h}$

$19.6h=324$

$h=\frac{324}{19.6}$

$=16.53 \ m$

8 0

3 years ago

Newton’s law of cooling states that dx dt = −k(x−A) where x is the temperature,t is time, A is the ambient temperature, and k &g

lys-0071 [83]

Answer:

a) $X= kA_o\dfrac{1}{k^2+\omega^2}\left ( kcos\omega t+\omega sin\omega t \right )+Ce^{-kt}$

b)Does not affect the long term.

Explanation:

Given that

$\dfrac{dx}{dt}=-k(x-A)$

A = A0 cos(ωt)

$\dfrac{dx}{dt}=-k(x-A_o cos(\omega t))$

$\dfrac{dx}{dt}+kx=kA_o cos(\omega t)$

This is linear equation so integration factor ,I

$I=e^{\int kdt}$

$I=e^{kt}$

Now by using linear equation property

$e^{kt} X=\int e^{kt} kA_o cos(\omega t) dt +C$

$e^{kt} X= kA_o \dfrac{e^{kt}}{k^2+\omega^2}\left ( kcos\omega t+\omega sin\omega t \right )+C$

$X= kA_o\dfrac{1}{k^2+\omega^2}\left ( kcos\omega t+\omega sin\omega t \right )+Ce^{-kt}$

at t= 0

$X(0)=\dfrac{k^2A_o}{\omega^2+k^2}+C$

$X= kA_o\dfrac{1}{k^2+\omega^2}\left ( kcos\omega t+\omega sin\omega t \right )+e^{-kt}\times \left ( X(0)-\dfrac{k^2A_o}{\omega^2+k^2} \right )$

So the initial condition does not affect the long term.

5 0

4 years ago