Blank objects is a major cause of back injuries in the workplace

Does the densoty of an object change if you add more of it because i did an expirement that proved that the density does change

Marysya12 [62]

No the density does not change. Density is a ratio D=m/v no matter how much of a substance you have its mass will be proportional.
When doing density labs sometimes you might get different answers due to errors that are unavoidable.

8 0

3 years ago

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Which of the following is an example of how pictures of a planet's surface can provide evidence about the planet's natural resou

Volgvan

I think it’s c but I’m not for sure

5 0

3 years ago

500 g of water at 90°C is cooled in a freezer. If all the water is converted to ice, what is the amount of heat released when th

KATRIN_1 [288]

Answer:

356 000 J

Explanation:

Total Energy released

= Energy released when water cools to 0 + Energy released when water is converted to ice at 0

= mcT + ml

= (0.5)(4200)(90-0) + (0.5)(334 000)

= 189 000 J + 167 000 J

= 356 000 J

4 0

3 years ago

An astronaut holds a rock 100 m above surface of Planet X. The rock is then thrown upwards with a sleek of 15m/s. The rock reach

Gelneren [198K]

Answer: $5 m/s^{2}$

Explanation:

This problem is related to vertical motion, and the equation that models it is:

$y=y_{o}+V_{o}sin\theta t-\frac{1}{2}gt^{2}$ (1)

Where:

$y=0m$ is the rock's final height

$y_{o}=100 m$ is the rock's initial height

$V_{o}=15 m/s$ is the rock's initial velocity

$\theta=90\°$ is the angle at which the rock was thrown (directly upwards)

$t=10 s$ is the time

$g$ is the acceleration due gravity in Planet X

Isolating $g$ and taking into account $sin(90\°)=1$ :

$g=(-\frac{2}{t^{2}})(y-y_{o}-V_{o}t)$ (2)

$g=(-\frac{2}{(10 s)^{2}})(0 m-100 m-(15 m/s)(10 s))$ (3)

$g=5 m/s^{2}$ (4) This is the acceleration due gravity in Planet X

5 0

3 years ago

One mole of a gas is placed in a closed system with a 20 L vessel initially at T = 300 K. The vessel is then isothermally expand

Elden [556K]

Answer:

Given that

P = RT/V + a/V²

We know that

H= U + PV

For T= Constant (ΔU=0)

ΔH= ΔU +Δ( PV)

ΔH= Δ( PV)

P = RT/V + a/V²

P V= RT + a/V

dH/dV = d(RT + a/V)/dV

dH/dV = - a/V²

So the expression of dH/dV

$\dfrac{dH}{dV}=\dfrac{-a}{V^2}$

b)

In isothermal process

$\Delta H=nRT\ln{\dfrac{V_2}{V_1}}$ (ΔU=0)

Now by putting the all values

$\Delta H=nRT\ln{\dfrac{V_2}{V_1}}$

$\Delta H=1\times 0.08206\times 300\ln{\dfrac{40}{20}}$

ΔH = 17.06 L.atm

8 0

3 years ago