Question 2 (1 point)

As a child (with a mass of 35.0 kg) you take your 5.0-kg sled to Orchard Downs. If you are sliding down the hill on your sled, w

alukav5142 [94]

Velocity = 3.61 m/s

<h3>Further explanation</h3>

Given

mass of child = 35 kg

mass of sled = 5 kg

Kinetic energy = 260 J

Required

velocity

Solution

Energy because its motion is expressed as Kinetic energy (KE) which can be formulated as:

KE = 1/2.mv²

mass of object :

= mass child + mass sled

= 35 kg + 5 kg

= 40 kg

Input the value :

v²=KE : 1/2.m

v²= 260 : 1/2.40 kg

v²=13

v=3.61 m/s

3 0

3 years ago

When electromagnetic radiation of wavelength 300nm falls on the surface of sodium electrons are emitted with a KE of 1.68 * 10 5

gtnhenbr [62]

Answer:

3.83 × 10⁻¹⁹ J; 518 nm

Step-by-step explanation:

The equation for the <em>photoelectric effect</em> is

hf = Φ + KE

λ = 300 nm = 300 × 10⁻⁹ m

KE = 1.68 × 10⁵ J/mol

Calculations:

Part 1. Minimum energy to remove an electron

(a) Calculate the <em>energy of the photon</em>

fλ = c

f = c/λ Divide each side by λ

E = hf

E = hc/λ

E = (6.626× 10⁻³⁴ × 2.998 × 10⁸)/(300 × 10⁻⁹)

E = 6.622 × 10⁻¹⁹ J

(b) Calculate the <em>KE of one electron</em>

KE = 1.68 × 10⁵ × 1/(6.022 × 10²³)

KE = 2.790 × 10⁻¹⁹ J

(c) Calculate the work function

hf = Φ + KE Subtract KE from each side

Φ = 6.622 × 10⁻¹⁹ - 2.790 × 10⁻¹⁹

Φ = 3.83 × 10⁻¹⁹ J

The minimum energy to remove an electron from a sodium atom

is 3.83 × 10⁻¹⁹ J.

Part 2. Maximum wavelength to remove an electron

The photon must have just enough energy to overcome the work function and leave the electron with zero kinetic energy.

E = Φ

hc/λ = Φ Multiply each side by λ

hc = Φ λ Divide each side by Φ

λ = hc/ Φ

λ = (6.626 × 10⁻³⁴ × 2.998 × 10⁸)/(3.83 × 10⁻¹⁹)

λ = 5.18 × 10⁻⁷ m Convert to nanometres

λ = 518 nm

The maximum wavelength that will cause an electron to move is 518 nm.

6 0

3 years ago

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Gas has a volume of 247.3 ML and is at 100 Celsius and 745 Hg. If the mass of the gas is 0.347 g what is the molar mass of the v

Ahat [919]

Answer:

The molar mass of the vapor is 43.83 g/mol

Explanation:

Given volume of gas = V = 247.3 mL = 0.2473 L

Temperature = T = 100 $^{\circ}C$ = 373 K

Pressure of the gas = P = 745 mmHg (1 atm = 760 mmHg)

$P = \displaystyle \frac{745}{760} \textrm{ atm} = 0.9802 \textrm{ atm}$

Mass of vapor = 0.347 g

Assuming molar mass of gas to be M g/mol

The ideal gas equation is shown below

$\textrm{PV} =\textrm{nRT} \\\textrm{PV} = \displaystyle \frac{m}{M}\textrm{ RT } \\0.98026 \textrm{ atm}\times 0.2473 \textrm{ L} = \displaystyle \frac{3.47 \textrm{ g}}{M}\times 0.0821 \textrm{ L.atm.mol}^{-1}.K^{-1}\times 373\textrm{K} \\M = 43.834 \textrm{ g/mol}$

The molar mass of the vapor comes out to be 43.834 g/mol

4 0

3 years ago

If the volume of 1.00 mole of gas is tripled, what will happen to the pressure, if the temperature remains constant

Julli [10]

Answer:

The new pressure becomes one third of the initial pressure.

Explanation:

The relation between pressure and volume at constant temperature is given by :

$P\propto \dfrac{1}{V}\\\\P=\dfrac{1}{V}$

Let new pressure and volume be P' and V' respectively.

V'=3V (given)

So,

$P'=\dfrac{1}{V'}\\\\=\dfrac{1}{3V}\\\\=\dfrac{1}{3}\times \dfrac{1}{V}\\\\P'=\dfrac{1}{3}\times P$

Hence, new pressure becomes one third of the initial pressure.

8 0

3 years ago

Using the periodic table, answer the following question..How many atoms of neon are in 0.378g of neon (a) 6.02 x 10²³ atoms (b)

zmey [24]

Answer:

B 1.87×10^-²

Explanation:

20.1797 g Neon = 1 mol

0.378 g Neon = y

(Cross multiply)

20.1797y= 0.378 x 1

(Make y the subject of the formula)

y = 0.878/ 20.1787

y = 0.0187317

y = 0.0187 approx

y = 1.87 x 10^-²

7 0

3 years ago

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