All categories

2 years ago

A change in color during a reaction is often a sign that a chemical change has occurred.

Physics

2 answers:

Inga [223]2 years ago

5 0

<h3><u>Answer;</u></h3>

The above statement is <u>True</u>;

A change in color during a reaction is often a sign that a chemical change has occurred.

<h3><u>Explanation</u>;</h3>

A change in color indicates the occurrence of a chemical change. This means a chemical reaction is occurring. The rearrangement of electrons between substances results in new substances being formed.
Additionally, changes in color, formation of a precipitate, temperature change or a change in pH also indicate the occurrence of a chemical reaction.

guajiro [1.7K]2 years ago

3 0

True, also fizzing and heat being released

You might be interested in

A lamp hangs from the ceiling at a height of 2.6 m. The lamp has a mass of 3.8 kg. The screws holding the lamp break, and it fal

iVinArrow [24]

Answer:

Explanation:

Given height of lamp from the ceiling = 2.6m

mass of the lamp = 3.8kg

acceleration due to gravity = 9.81m/s²

As the body falls to the ground, it falls under the influence of gravity.

Gravitational potential energy = mass*acc due to gravity * height

Gravitational potential energy = 3.8*2.6*9.81

Gravitational potential energy = 96.923 Joules

b) Kinetic energy = 1/2 mv²

m = mass of the body (in kg)

v = velocity of the body (in m/s²)

To get the velocity v, we will use the equation of motion $v^{2} = u^{2}+2gh$

$v^{2} = 0^{2}+2(9.81)(2.6) \\v^{2} = 51.012\\v =\sqrt{51.012}\\ v = 7.14m/s$

Since mass = 3.8kg

$K.E = 1/2 * 3.8 *7.14^{2}\\ K.E = 96.86Joules$

c) To know how fast the lamp is moving when it hits the ground, we will use the formula. When the body hits the ground, the height covered will be 0m. this means that the body is not moving once it hits the ground. It stays in one position. The energy possessed by the body at this point is potential energy. The correct answer is therefore 0 m/s

4 0

2 years ago

The fluid pressure 10 ft underwater is _____ the fluid pressure 5 ft underwater. A.less than or greater than, depending on what

just olya [345]

<span>I would say greater than because as you do deeper, the pressure strengthens. If you were in a 10 ft deep pool and you dive all the way to the bottom, the ears usually pop. That's because of the pressure. Whereas if you were to go five feet, your ears wouldn't. It depends on the age of the person. Hope this helps.</span>

5 0

3 years ago

Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The

bazaltina [42]

Answer:

The current in the rods is 171.26 A.

Explanation:

Given that,

Length of rod = 0.85 m

Mass of rod = 0.073 kg

Distance $d = 8.2\times10^{-3}\ m$

The rods carry the same current in the same direction.

We need to calculate the current

I is the current through each of the wires then the force per unit length on each of them is

Using formula of force

$\dfrac{F}{L}=\dfrac{\mu_{0}I^2}{2\pi d}$

$\dfrac{mg}{L}=\dfrac{\mu_{0}I^2}{2\pi d}$

Where, m = mass of rod

l = length of rod

Put the value into the formula

$I^2=\dfrac{mgd}{\mu L}$

$I^2=\dfrac{0.073\times9.8\times8.2\times10^{-3}}{2\times10^{-7}}$

$I=\sqrt{29331.4}$

$I=171.26\ A$

Hence, The current in the rods is 171.26 A.

5 0

2 years ago

What types of landforms can water form?

Alika [10]

Lakes and rivers can be formed landforms from water

4 0

2 years ago

A physics student of mass 43.0 kg is standing at the edge of the flat roof of a building, 12.0 m above the sidewalk. An unfriend

Dmitry_Shevchenko [17]

Answer:

The speed of the student just before she lands, v₂ is approximately 8.225 m/s

Explanation:

The given parameters are;

The mass of the physic student, m = 43.0 kg

The height at which the student is standing, h = 12.0 m

The radius of the wheel, r = 0.300 m

The moment of inertia of the wheel, I = 9.60 kg·m²

The initial potential energy of the female student, P.E.₁ = m·g·h₁

Where;

m = 43.0 kg

g = The acceleration due to gravity ≈ 9.81 m/s²

h = 12.0 h

∴ P.E.₁ = 43 kg × 9.81 m/s² × 12.0 m = 5061.96 J

The kinetic rotational energy of the wheel and kinetic energy of the student supporting herself from the rope she grabs and steps off the roof, K₁, is given as follows;

$K_1 = \dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2$

The initial kinetic energy, 1/2·m·v₁² and the initial kinetic rotational energy, 1/2·m·ω₁² are 0

∴ K₁ = 0 + 0 = 0

The final potential energy of the student when lands. P.E.₂ = m·g·h₂ = 0

Where;

h₂ = 0 m

The final kinetic energy, K₂, of the wheel and student is give as follows;

$K_2 = \dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2$

Where;

v₂ = The speed of the student just before she lands

ω₂ = The angular velocity of the wheel just before she lands

By the conservation of energy, we have;

P.E.₁ + K₁ = P.E.₂ + K₂

∴ m·g·h₁ + $\dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2$ = m·g·h₂ + $\dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2$

Where;

ω₂ = v₂/r

∴ 5061.96 J + 0 = 0 + $\dfrac{1}{2} \times 43.0 \, kg \times v_{2}^2+\dfrac{1}{2} \times 9.60 \, kg\cdot m^2 \cdot \left (\dfrac{v_2}{0.300 \, m} }\right ) ^2$

5,061.96 J = 21.5 kg × v₂² + 53. $\overline 3$ kg × v₂² = 21.5 kg × v₂² + 160/3 kg × v₂²

v₂² = 5,061.96 J/(21.5 kg + 160/3 kg) ≈ 67.643118 m²/s²

v₂ ≈ √(67.643118 m²/s²) ≈ 8.22454363 m/s

The speed of the student just before she lands, v₂ ≈ 8.225 m/s.

5 0

2 years ago