All categories

3 years ago

Am sorry but. What about these three

Physics

1 answer:

frosja888 [35]3 years ago

3 0

c is physical ie not chemical reaction ...

mass cannot be created or destroyed. in chem reaction, mass before reaction = total mass after. that would incl any gas

water. find the mass of, say, 100cc. divde the mass by the volume.

water = 1000kg/cubic metre. a lot of water ...

You might be interested in

You are sitting on a merry-go-round of mass 200 kg and radius 2m that is at rest (not spinning). Your mass is 50 kg. Your friend

Bogdan [553]

Answer:

a. $\tau=200J$ b. $\alpha=0.44 \frac{rad}{s^2}$ c. $\alpha=0.33\frac{rad}{s^2}$ d. The angular acceleration when sitting in the middle is larger.

Explanation:

a. The magnitude of the torque is given by $\tau=rF\sin \theta$ , being r the radius, F the force aplied and $\theta$ the angle between the vector force and the vector radius. Since $\theta=90^{\circ}, \, \sin\theta=1$ and so $\tau=rF=2m100N=200Nm=200J$ .

b. Since the relation $\tau=I\alpha$ hols, being I the moment of inertia, the angular acceleration can be calculated by $\alpha=\frac{\tau}{I}$ . Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is $I=\frac{1}{2}Mr^2$ , being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by $I_p=m_pr_p^{2}$ , being $m_p$ the mass of the person and $r_p^{2}$ the distance from the person to the center. Given all of this, we have

$\alpha=\frac{\tau}{I}=\frac{\tau}{I_{disk}+I_{person}}=\frac{Fr}{\frac{1}{2}Mr^2+m_pr_p^{2}}=\frac{200Nm}{\frac{1}{2}200kg*4m^2+50kg*1m^2}=\frac{200\frac{kgm^2}{s^2}}{450Nm^2}\approx 0.44\frac{rad}{s^2}$ .

c. Similar equation to b, but changing $r_p=2m$ , so

$alpha=\dfrac{200\frac{kgm^2}{s^2}}{\frac{1}{2}200*4kg\,m^2+50*4 kg\,m^2}=\dfrac{200}{600}\dfrac{1}{s^2}\approx 0.33 \frac{rad}{s^2}$ .

d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.

5 0

2 years ago

The billiard ball model was the working model of the atom until thomson discovered the

zysi [14]

<span>d. electron

J J Thomson discovered the electron, and it was put in his model of the atom.</span>

3 0

3 years ago

Read 2 more answers

Explain with one example that different types of organisums live in one habitation

inn [45]

Answer:

When you look at a simple koi pond you can find Koi (the secondary consumer) that feeds off of the zooplankton (first consumer), they eat the phytoplankton (producers). All in a simple food chain

Explanation:

Basically, Koi eat the little animal plankton (zooplankton) that then eats the plant plankton (phytoplankton) that can only end when a part of that habitat is removed. If you got rid of the plant plankton then the whole chain would collapse and most likely die.

5 0

2 years ago

A 700 kg car makes a turn going at 30 m/s with radius of

Gnoma [55]

Answer:5250 N

Explanation: ig:iihoop.vince

5 0

2 years ago

For an atom to be neutral the amount of ? and? must be equal

maks197457 [2]

Answer: Well first of all, for an Atom to be neutral, it shall have an equal number of the protons and the neutrons. So given that, the protons are able to be positively charged and since the electrons are negatively charged (Protons and Electrons are completely different from each other) then that means the Algebric are aggregated of charges because it equal to zero. So overall, the 'neutral atom' has to be neutral, and how? Protons must equal the number of electrons or else it wouldn't be considered neutral.

Hopefully this helps you very much!! :-) Have a great daayy!

6 0

3 years ago

Read 2 more answers