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3 years ago

Which electromagnetic wave enables us to see objects?

2 answers:

4 0

I believe the correct answer from the choices listed above is option B. It is the visible light that enables us to see objects. A typical human eye will respond to wavelengths from about 390 to 700 nm which is the visible light. Hope this answers the question.

Valentin [98]3 years ago

3 0

Choose visible light

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qizlet, The concentration of a diluted "wine" sample was found to be 0.32 %(v/v) ethanol. Assuming the wine was diluted by 50x b

Semmy [17]

Answer:

The original concentration of ethanol is 16%(v/v)

Explanation:

concentration before dilution, C1 = ?

Concentration after dilution, C2 = 0.32% (v/v)

Volume before dilution, V1 = x

Volume after dilution, V2 = 50x

From the dilution principle

C1V1 = C2V2

(C1) * x = (0.32) * 50x

C1 = (16x)/x

C1 = 16%(v/v)

6 0

4 years ago

(OUR

natta225 [31]

George's speed per second is 76.92 m/s

George's velocity in meters per second was 38.46 m/s (North)

Explanation:

When dividing the total distance covered by object by time, we get the value for average speed.

$\text { speed }=\frac{\text {distance}}{\text {time}}$

Given:

t = 13 seconds

Calculate the distance without consideration of motion’s direction. So, the distance walks 750 m north first, and then turn around walks 250 m south, so the total distance covered is

d = 750 + 250 = 1000 meters

To find the rate per second, simply divide the distance by the time.

$\text { speed }=\frac{1000}{13}=76.92 \mathrm{m} / \mathrm{s}$

In given case, the students walks 750 m north first, and then turn around walk 250 m south. The displacement is the distance in a straight line between the initial and final position: therefore, in this case, the displacement is

d = 750 (north) - 250 (south) = 500 m (north)

The time taken is t = 13 s

So, the average velocity is $\text {velocity}=\frac{500}{13}=38.46 \mathrm{m} / \mathrm{s}$ (North)

And the direction is north (the same as the displacement).

3 0

4 years ago

On average, both arms and hands together account for 13 % of a person's mass, while the head is 7.0% and the trunk and legs acco

lianna [129]

Answer:

$\dot n_{f} = 85.177\,rpm$

Explanation:

The expression for the moment of inertia of the person is:

Arms outstretched

$I = \frac{1}{12}\cdot (0.13)\cdot (61\,kg)\cdot (1.40\,m)^{2} + \frac{1}{2}\cdot (0.87)\cdot (61\,kg)\cdot (0.35\,m)^{2}$

$I = 4.546\,kg\cdot m^{2}$

Arms parallel to the trunk

$I = \frac{1}{2}\cdot (61\,kg)\cdot (0.35\,m)^{2}$

$I = 3.736\,kg\cdot m^{2}$

The final angular speed is found by means of the Principle of Angular Momentum Conservation:

$I_{o}\cdot \dot n_{o} = I_{f}\cdot \dot n_{f}$

$\dot n_{f} = \frac{I_{o}}{I_{f}}\cdot \dot n_{o}$

$\dot n_{f} = \left(\frac{4.546\,kg\cdot m^{2}}{3.736\,kg\cdot m^{2}}\right)\cdot (70\,rpm)$

$\dot n_{f} = 85.177\,rpm$

8 0

3 years ago

In an electrical circuit, "_____" refers to the rate at which electrical energy is transformed into another kind of energy.

Tems11 [23]

Answer:

Electrical power

Explanation:

Electrical power: Electric power (P) is defined as the energy (W) used or produced or transformed per seconds.

Power = Energy produced/transformed/time taken.

P = W/t................................ Equation 1

Where t = time taken

But,

W = VIt................................ Equation 2

Substituting equation 2 into equation 1

P = VIt/t

P = VI............................ Equation 3

P = V²/R or P = I²R.

The unit of power is J/s or Volt-ampere is called watt (W).

Large amount of electric power are required in the industry

1 kW = 1000 W

1 MW = 1000000 W

1 h.p = 3/4 kW.

8 0

3 years ago

Which of the following best describes a substance in which the temperature remains constant while at the same time it is experie

katen-ka-za [31]

Answer:

The right option is (d) substance undergoing a change of state

Explanation:

Latent Heat: Latent heat is the heat required to change the state of a substance without change in temperature. Latent heat is also known as hidden heat because the heat is not visible. The unit is Joules (J).

Latent heat is divided into two:

⇒ Latent Heat of fusion

⇒ Latent Heat of vaporization.

Latent Heat of fusion: This is the heat energy required to convert a substance from its solid form to its liquid form without change in temperature. E.g (Ice) When ice is heated, its temperature rise steadily until a certain temperature is reached when the solid begins to melts.

Latent Heat of vaporization: This is the heat required to change a liquid substance to vapor without a change in temperature. The latent heat depend on the mass of the liquid and the nature of the liquid. E.g When water is heated from a known temperature its boiling point (100°C) When more heat is supplied to its boiling temperature, it continue to boil without a change in temperature.

From The above, Latent heat brings about a change of state of a substance at a steady temperature.

The right option is (d) substance undergoing a change of state

4 0

4 years ago