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2 years ago

What gives an object gravity?

1 answer:

8 0

We don't know WHY there are gravitational forces that attract everything
to everything else.

We DO know that the more mass is involved, the stronger the forces are,
and we know that if an object had no mass then it wouldn't be affected by
gravity. So you could say that it's MASS that gives an object gravity, and
the more mass the object has, the more gravity it has.

You might be interested in

Gases are more prone to expansion and contraction than liquid . The biggest change in the volume in your thermometer was probabl

KiRa [710]

Answer:

In the air

Explanation:

There are three states of matter:

- Solids: in solids, the particles are tightly bond together by strong intermolecular forces, so they cannot move freely - they can only vibrate around their fixed position

- Liquids: in liquids, particles are more free to move, however there are still some intermolecular forces keeping them close to each other

- Gases: in gases, particles are completely free to move, as the intermolecular forces between them are negligible

For this reason, it is generally easier to compress/expand the volume of a gas with respect to the volume of a liquid.

In this problem, we are comparing water (which is a liquid) with air (which is a gas). From what we said above, this means that the change in volume is larger in the air rather than in the water.

8 0

2 years ago

Air at 400 kPa, 980 K enters a turbine operating at steady state and exits at 100 kPa, 670 K. Heat transfer from the turbine occ

Angelina_Jolie [31]

Answer:

a). $\frac{\dot{W}}{m}= 311$ kJ/kg

b). $\frac{\dot{\sigma _{gen}}}{m}=0.9113$ kJ/kg-K

Explanation:

a). The energy rate balance equation in the control volume is given by

$\dot{Q} - \dot{W}+m(h_{1}-h_{2})=0$

$\frac{\dot{Q}}{m} = \frac{\dot{W}}{m}+m(h_{1}-h_{2})$

$\frac{\dot{W}}{m}= \frac{\dot{Q}}{m}+c_{p}(T_{1}-T_{2})$

$\frac{\dot{W}}{m}= -30+1.1(980-670)$

$\frac{\dot{W}}{m}= 311$ kJ/kg

b). Entropy produced from the entropy balance equation in a control volume is given by

$\frac{\dot{Q}}{T_{boundary}}+\dot{m}(s_{1}-s_{2})+\dot{\sigma _{gen}}=0$

$\frac{\dot{\sigma _{gen}}}{m}=\frac{-\frac{\dot{Q}}{m}}{T_{boundary}}+(s_{2}-s_{1})$

$\frac{\dot{\sigma _{gen}}}{m}=\frac{-\frac{\dot{Q}}{m}}{T_{boundary}}+c_{p}ln\frac{T_{2}}{T_{1}}-R.ln\frac{p_{2}}{p_{1}}$

$\frac{\dot{\sigma _{gen}}}{m}=\frac{-30}{315}+1.1ln\frac{670}{980}-0.287.ln\frac{100}{400}$

$\frac{\dot{\sigma _{gen}}}{m}=0.0952+0.4183+0.3978$

$\frac{\dot{\sigma _{gen}}}{m}=0.9113$ kJ/kg-K

5 0

3 years ago

I need help with some graph.<br><br> Which graph shows acceleration?

matrenka [14]

Answer:

The first graph

Explanation:

Graph A shows acceleration.

4 0

2 years ago

Read 2 more answers

Nana76 [90]

Answer:

Electron shell

Nucleus

Neutrons

Explanation:

An atom is made up of three fundamental subatomic particles which are the protons, neutrons and electrons.

Protons are the positively charged particles. Neutrons do not carry any charges.
Both protons and neutrons are found in the tiny nucleus at the center of that atom.
The electrons are negatively charged.
They are found outside the nucleus in electronic shells.

5 0

2 years ago

A baseball bat balances 74.9 cm from one end. If an 0.560-kg glove is attached to that end, the balance point moves 25.3 cm towa

timurjin [86]

Answer:

The mass of the bat is 1.09 kg.

Explanation:

Given that,

The balance point of the glove, x = 74.9 cm

Mass of the glove, m = 0.56 kg

Center of mass of the baseball bat, C = 25.3 cm

Let M is the mass of the bat. The center of mass is given by the formula as :

$C=\dfrac{MX+mx}{M+m}$

X is 0 as it is at a end

$C=\dfrac{mx}{M+m}$

$25.3=\dfrac{0.56\times 74.9}{M+0.56}$

M = 1.09 kg

So, the mass of the bat is 1.09 kg. Hence, this is the required solution.

3 0

2 years ago