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3 years ago

What are two reasons why density is a useful physical property for identifying substances?

1 answer:

4 0

Some substances look alike and the density can help you determine which is which. It also helps to tell which is heavier than the other.

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A cube has a drag coefficient of 0.8. What would be the terminal velocity of a sugar cube 1 cm on a side in air ( = 1.2 kg/mº)?

anzhelika [568]

0.495 m/s

Explanation

the formula for the terminal velocity is given by:

$\begin{gathered} v=\sqrt[]{\frac{2mg}{\sigma AC}} \\ \text{where} \\ \end{gathered}$

m is the mass

g is 9.81 m/s²

ρ is density

A is area

C is the drag coefficient

then

Step 1

Let's find the mass

$\begin{gathered} \sigma=\frac{m}{v} \\ m=\sigma\cdot v \\ \text{mass}=(2\cdot10^3\frac{\operatorname{kg}}{m^3})\cdot(0.01m)^3 \\ \text{mass}=(2\cdot10^3\frac{\operatorname{kg}}{m^3})\cdot(1\cdot10^{-6}) \\ \text{mass}=2\cdot10^{-3}\operatorname{kg} \\ \text{mass}=0.002\text{ kg } \\ \text{Area}=(0.01\text{ m}\cdot0.01m)=0.0001m^2 \end{gathered}$

now, replace

$\begin{gathered} v=\sqrt[]{\frac{2mg}{\sigma AC}} \\ v=\sqrt[]{\frac{2(0.002kg)(9.81\text{ }\frac{m}{s^2})}{(2\cdot10^3\frac{\operatorname{kg}}{m^3})(0.0001m^2)0.8}} \\ v=\sqrt[]{\frac{0.03924\frac{\operatorname{kg}m}{s^2}}{0.16\frac{\operatorname{kg}}{m^{}}}} \\ v=\sqrt[]{0.2452\frac{m^2}{s^2}} \\ v=0.495\text{ m/s} \end{gathered}$

hence, the answer is 0.495 m/s

3 0

1 year ago

A trio of students push a 65 kg crate. The first student pushes 31 N [e], the second student pushes 28 N [s] and the third stude

Verdich [7]

Answer:

The free body diagram is attached.

Explanation:

A force of 31[N] to the east, the second force goes to the south and it is equal to 28[N], the third force goes to the west and it is equal to 39 [N].

We can consider the crate as a particle. And all the forces are acting over the particle.

5 0

3 years ago

a crane lifts a 75 kg mass at a height of 8m . calculate the gravitational potential energy gained by the mass (g= 10N)

Bogdan [553]

Advice: Search up your questions in the Brainly search bar before asking your questions.

5 0

3 years ago

Which scenario would be classified as a conceptual model

den301095 [7]

Answer:

Heyo! (Ish Mash Potato) XD

Explanation:

A conceptual model is a representation of a system, made of the composition of concepts which are used to help people know, understand, or simulate a subject the model represents. It is also a set of concepts. Some models are physical objects; for example, a toy model which may be assembled, and may be made to work like the object it represents.

Hope Mr. Mash Potato Helped!!!

3 0

3 years ago

Read 2 more answers

Shondra takes notes in class.

sdas [7]

Answer:

I beileve its A because energy is what gives the ability to do work

Explanation:

4 0

3 years ago