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2 years ago

What is a substance

Physics

1 answer:

Ulleksa [173]2 years ago

4 0

Well, if i am correct. a substance is:

a particular kind of matter with uniform properties

or...

the real physical matter of which a person or thing consists and which has a tangible, solid presence.

choose which ever you like better:)

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4. Uncle Harry weighs 180 pounds. What is his mass in kilograms?

MatroZZZ [7]

180 pounds (lb) converts to 81.647 kilograms (kg).

5 0

2 years ago

A hazard sign has 3 identical

melomori [17]

Answer and Explanation: To know how much tape he will need, we have to calculate the perimeter of each parallelogram-shaped stripe.

Perimeter is the sum of all the sides of a figure.

For a parallelogram:

P = 2*length + 2*width

So, we need to determine width and length of the stripe.

Width is 3 inches. Length is the hypotenuse of the right triangle, whose sides are 6 and 18 inches. Then, length is

$h=\sqrt{18^{2}+6^{2}}$

$h=\sqrt{360}$

h = 19 in

Perimeter of the first stripe is

P = (2*19) + (2*3)

P = 44 inches

The hazard sign has 3 stripes. So total perimeter is

$P_{t}=$ 44 + 44 + 44

$P_{t}=$ 132 inches

To outline the parallelogram-shaped stripes, Charles need a total of 132 inches of tape. Since one roll has 144 inches, he will have enough tape to finish the job.

5 0

2 years ago

The age and crisis of the stage trust vs. mistrust

hodyreva [135]

Trust vs. mistrust is the first stage in Erik Erikson's theory of psychosocial development. This stage begins at birth continues to approximately 18 months of age. ... If the care has been inconsistent, unpredictable and unreliable, then the infant may develop a sense of mistrust, suspicion, and anxiety.
Hope it is helpful

6 0

3 years ago

Steel train rails are laid in 12.0-m-long segments placed end to end. The rails are laid on a winter day when their temperature

Yanka [14]

Answer:

a) Space = $6.05 x 10^{-3} m = 0.605 cm$

b) Stress= $-100.8 x 10^{6} Pa$

Explanation:

1) Data Given

$L = 12 m , T_i = -9 C \degree, T_f = 33 C \degree$

2) Calculate the space using Linear thermal expansion formula

We need to use Linear thermal expansion formula since the space created would be a change on 1 dimension, the increase of the temperature will increase the length of the steel. The formula is given by:

$\Delta L = L_i \alpha_{steel} \Delta T$

We have everything except the $\alpha_{steel}$ , so we look for this on a book and we find that $\alpha_{steel} = 1.2 x 10^{-5} C^{-1}$ , so we can replace.

$\Delta L = 12 m (1.2 x 10^{-5} C^{-1}) (33 C \degree -(-9 C \degree)) = 12 m (1.2 x 10^{-5} C^{-1}) 42 C \degree =6.048 x 10^{-3} m = 0.6048cm$

3) Calculate the stress of the steel

The Stress is the ratio of applied force F to a cross section area - defined as

$\sigma = \frac{F_n}{A}$

Since we don't have the force and the Area, we need to look for another way to find the stress.

For this we can use the concept called Young's Modulus, defined as : "the mechanical property that measures the stiffness of a solid material", and the formula for this is given by:

$Y =\frac{F L}{A \Delta L}$ (1)