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3 years ago

13. Litmus paper can be used to determine if a solution is an acid or a base. There are two types of

Physics

1 answer:

Over [174]3 years ago

7 0

Answer:

The main use of litmus is to test whether a solution is acidic or basic. Light Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). Neutral litmus paper is purple.

Explanation:

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When all parts of a circuit are composed of conducting materials, the circuit is said to be

den301095 [7]

When all parts of a circuit ... all the way from one terminal of the
battery or power supply to the other terminal ... are composed of
conducting materials, then current can flow in the circuit, and the
circuit is said to be 'closed'.

4 0

4 years ago

A small metal sphere has a mass of 0.11 g and a charge of -21.0 nC . It is 10 cm directly above an identical sphere with the sam

GrogVix [38]

Answer:

A. the magnitude of the force between the spheres is 3.97 x 10⁻⁴ N

B. the magnitude of its initial acceleration is 5.83 m/s²

Explanation:

given information:

metal sphere's mass, m = 0.1 g = 1 x 10⁻⁴ kg

charge, q = -21 nC = -2.1 x 10⁻⁸

r = 10 cm = 0.1 m

What is the magnitude of the force between the spheres?

F₁₂ = k q₁q₂/r²

= ( 9 x 10⁹) (-2.1 x 10⁻⁸)²/(0.1)²

= 3.97 x 10⁻⁴ N

If the upper sphere is released, it will begin to fall. What is the magnitude of its initial acceleration?

mg - F₁₂ = ma

a = g - (F₁₂/m)

= 9.8 - (3.97 x 10⁻⁴/1 x 10⁻⁴)

= 5.83 m/s²

5 0

3 years ago

A nichrome wire and an aluminum wire, each with the same initial resistance, have the same change in resistance when heated sepa

Svetach [21]

Answer:

The ratio of temperature change of nichrome wire to the temperature change of aluminum wire is found to be <u>9.75</u>

Explanation:

The change in resistances and initial resistances of the wires are:

Change in Resistance of Nichrome Wire = ΔR₁

Change in Resistance of Aluminum Wire = ΔR₂

Initial Resistance of Nichrome Wire = R₁

Initial Resistance of Aluminum Wire = R₂

Also, it is given that the change in resistance and initial resistance of both wires is equal. Therefore,

ΔR₁ = ΔR₂ ---------- eqn (1)

R₁ = R₂ ---------- eqn (2)

The change in Resistance due to temperature is given by formula:

ΔR = R α ΔT

Therefore, eqn (1) becomes:

R₁ α₁ ΔT₁ = R₂ α₂ ΔT₂

using eqn (2):

α₁ ΔT₁ = α₂ ΔT₂

ΔT₁/ΔT₂ = α₂/α₁

where,

α₁ = Temperature coefficient of resistance of nichrome = 0.4 x 10⁻³ °C⁻¹

α₂ = Temperature coefficient of resistance of aluminum = 3.9 x 10⁻³ °C⁻¹

Therefore,

ΔT₁/ΔT₂ = (3.9 x 10⁻³ °C⁻¹)/(0.4 x 10⁻³ °C⁻¹)

6 0

4 years ago

Sam heats an 8kg sample of sand, with a specific heat of 664 J/kg·C°, from 20° to 40°. What is the change in thermal energy?

zysi [14]

Answer:

106.24 kJ.

Explanation:

Given that,

Mass of sample of sand, m = 8 kg

Specific heat of sand, c = 664 J/kg-°C

The temperature changes from 20° C to 40° C. We need to find the change in thermal energy. It is given by :

$Q=mc\Delta T\\\\Q=8\times 664(40-20)\\\\=106240\ J\\\\=106.24\ kJ$

So, the change in thermal energy is 106.24 kJ.

7 0

3 years ago

What is a true statement about the rotation period of the moon?

mrs_skeptik [129]

The time it takes for the Moon to rotate once around its axis is equal to the time it takes for the Moon to orbit once around Earth

5 0

3 years ago