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3 years ago

A thermos bottle works well because:

Physics

2 answers:

baherus [9]3 years ago

7 0

Answer:

A thermos bottle works well because:

A) Its glass walls are thin

soldi70 [24.7K]3 years ago

4 0

Answer:

A thermos bottle works well because:

Vacuum reduces heat radiation

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What are 5 landforms formed by river erosion

horsena [70]

Valleys, waterfalls, flood plains, meanders, and oxbow lakes

8 0

3 years ago

A chemical equation lists NaHCO3(s) as a reactant. What does (s) indicate?

Ostrovityanka [42]

Answer:

The (s) indicates that the state of matter for NaHCO3 is solid.

Explanation:

When a chemical reaction is written, the state of matter for each components of the reactants and products are mentioned in brackets along with their names or formulas.

For example, NaHCO3 has (s) mentioned in the brackets. The s shows that the state of matter for NaHCO3. (l) represents liquid format. (g) represents that the state of matter is gas.

5 0

3 years ago

Read 2 more answers

A 4.5-kg, three legged stool supports a 89-kg person. If each leg of the stool has a cross-sectional diameter of 2.8 cm and the

kkurt [141]

Answer:

4.96 × 10⁵ Pa

Explanation:

F = mg

$F = (m_{person}+m_{stool})g\\\\F = (4.5 + 89)*9.8\\\\F = 916.3 N$

This force is evenly distributed on the three leg

radius, r = d/2

= 2.8 / 2

= 1.4 cm = 0.014 m

total cross sectional area of the three legs, A = 3*pi*r^2

$= 3\times\pi \times0.014^2\\\\= 1.847\times10^-^3m^2$

Pressure due to weight,

P = Weight/A

$P = / 1.847 × 10⁻³\\P = \frac{ 916.3N}{1.847\times10^-^3} \\\\P= 496032.9Pa$

P = 4.96 × 10⁵ Pa

8 0

3 years ago

Assuming that Albertine's mass is 60.0 kg , for what value of μk, the coefficient of kinetic friction between the chair and the

makvit [3.9K]

Answer:

$\mu_k=0.101$

Explanation:

It is given that,

Mass of Albertine, m = 60 kg

It can be assumed, the spring constant of the spring, k = 95 N/m

Compression in the spring, x = 5 m

A glass sits 19.8 m from her outstretched foot, h = 19.8 m

When she just reach the glass without knocking it over, a force of friction will also act on it. Using the conservation of energy for the spring mass system such that,

$\dfrac{1}{2}kx^2=\mu_k mgh$

$\mu_k=\dfrac{kx^2}{2mgh}$

$\mu_k=\dfrac{95\times (5)^2}{2\times 60\times 9.8\times 19.8}$

$\mu_k=0.101$

So, the coefficient of kinetic friction between the chair and the waxed floor is 0.101. Hence, this is the required solution.

3 0

3 years ago

A rock with a mass of 0.3 kg falls from the top of a cliff. If it takes the rock 2.5 s to reach the ground, what was the impulse

kaheart [24]

Impulse=force x time
force=mass x acceleration due to gravity
force=
$300 \times 10 = 3000$
impulse =3000 x 2.5= ( sorry i don't have a calculator right now so you must calculate this yourself)
I converted from kg to g because it is the standard.
Hope this helps you.

4 0

3 years ago