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3 years ago

A 2-kg book falls off a shelf. it hits a student traveling 2 m/s. how much kinetic energy does the book have?

Physics

1 answer:

jekas [21]3 years ago

5 0

Kinetic energy = 1/2 * m * V^2

K = 1/2 * 2kg * 4

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What is the freezing point of an aqueous solution that boils at 101 degrees C? Kfp = 1.86 K/m and Kbp = 0.512 K/m. Enter your an

astra-53 [7]

Answer:

-3.63 degree Celsius

Explanation:

We are given that

Boiling point of solution= $T_b=101^{\circ}$ C

Boiling point water=100 degree Celsius

$K_f=1.86K/m$

$K_b=0.512 K/m$

$\Delta T_b=T-T_0$

Where $T$ =Boiling point of solution

$T_0=$ Boiling point of pure solvent

$\Delta T_b=101-100=1^{\circ}$ C

$\Delta T_b=k_bm$

Using the formula

$1=0.512\times m$

Molality, $m=\frac{1}{0.512}$ m

$\Delta T_f=k_fm$

Using the formula

$\Delta T_f=\frac{1}{0.512}\times 1.86$

$\Delta T_f=3.63 C$

We know that

$\Delta T_f=T_0-T_1$

Where $T_0$ =Freezing point of solvent

$T_1=$ Freezing point of solution

Using the formula

$3.63=0-T_1$

Freezing point of water=0 degree Celsius

$T_1=0-3.63=-3.63 C$

Hence, the freezing point of solution=-3.63 degree Celsius

7 0

3 years ago

A sample of gold has a volume of 2 cm3 and a mass of 38.6 grams. What would be the density, and three other properties of the sa

lukranit [14]

The density of the gold is calculated to be "19,300 kg/m³".

<u>Explanation:</u>

Given:

Volume = 2cm³

Mass = 38.6 grams.

To Find:

Density of the gold = ?

Solution:

Density is obtained by dividing mass of the sample by its volume and it is given in the units of kg/m³.

Mass in grams is converted into kg as,

1 g = 0.001 kg

38. 6 g = $\frac{38.6}{1000} = 0.0386 kg$

Now we have to convert cm³ to m³ as,

1 cm³ = 10⁻⁶ m³

2 cm³ = 2 × 10⁻⁶ m³

So Density = $\frac{0.0386 k g}{2 \times 10^{-6} m^{3}}=19,300 \mathrm{kg} / \mathrm{m}^{3}$

Physical properties of Gold:

Gold is a heavy metal.

It is Malleable and ductile.

It is a corrosion resistant element.

3 0

3 years ago

If the speed of a wave doubles while the frequency remains the same, it means

sattari [20]

Answer:

Explanation:

Velocity of a wave is describe as

velocity =Frequency × Wavelength

Mathematically

v = fλ

Hence, Frequency, F = v / λ

Wavelength λ = v/f

So, if the frequency is kept constant, wavelength of the wave becomes directly proportional to velocity of the wave.

And this implies that, as the speed double, the wavelength is double.

5 0

4 years ago

Dark cooler areas on the sun's surface are called what? (Prominences, solar flares, coronas, or sunspot)

Serhud [2]

Darker, cooler areas on the sun's surface are called sunspots.
Hope that helped =)

7 0

3 years ago

Read 2 more answers

Which shows one example of physical change and the one example of a chemical change?

atroni [7]

Answer:

D. Freezing water and burning coal

Explanation:

8 0

3 years ago