answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Oksi-84 [34.3K]
2 years ago
6

A 75 lb (34 kg) boy falls out of a tree from a height of 10 ft (3 m). i. What is the kinetic energy of the boy when he hits the

ground? Round your answer to the nearest joule. ii. What is the speed of the boy when he hits the ground? Round your answer to two significant figures. iii. Using the conversion factors of 1 m = 1.094 yd and 1 mi = 1760 yd, calculate the speed of the boy in miles per hour when he hits the ground.
Chemistry
1 answer:
Jobisdone [24]2 years ago
4 0

Answer:

Kinetic energy of boy just before hitting the ground is \approx1000 J.

Speed of boy just before hitting the ground is 7.67 m/s

or 17.16 mi/hr.

Explanation:

Given that:

Mass of boy = 75lb = 34 kg

Height, h = 10ft = 3m

To find:

Kinetic energy of boy when he hits the ground.

<em>As per law of conservation of energy The potential energy gets converted to kinetic energy.</em>

<em></em>

<em></em>\therefore<em> </em>Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'

The formula for potential energy is given as:

PE = mgh

Where m is the mass

g is the acceleration due to gravity, g = 9.8 m/s^2

h is the height of object

Putting all the values:

PE = 34 \times 9.8 \times 3 \approx 1000\ J

Hence, Kinetic energy is \approx1000 J.

Formula for Kinetic energy is:

KE = \dfrac{1}{2}mv^2

where m is the mass and

v is the speed

Putting the values and finding v:

1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s

Given that:

1 m = 1.094 yd and 1 mi = 1760 yd

\Rightarrow 1609\ m = 1\ mi

Converting 7.67 m/s to miles/hour:

\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h

You might be interested in
Consider the acid H3PO4. This acid will react with water by the following equation. H3PO4+H2O↽−−⇀H2PO−4+H3O+ What will be true o
Sonbull [250]

Answer:

H+/PO-4^-2

Explanation:

hydrogen has dissolved completely

7 0
2 years ago
How many acidic protons are there in 0.6137 g of KHP?
andreyandreev [35.5K]

0.6137 g of KHP contains 1.086 × 10^21 acidic protons.

Number of moles of KHP = mass of KHP/molar mass of KHP

Molar mass of KHP = 204.22 g/mol

Mass of KHP = 0.6137 g

Number of moles of KHP = 0.6137 g/204.22 g/mol = 0.003 moles of KHP

Now,  1 each molecule of KHP contains 1 acidic proton.

For 0.003 moles of KHP there are; 0.003 × 1 × NA

Where NA is Avogadro's number.

So;  0.003 moles of KHP contains 0.003 × 1 × 6.02 × 10^23

= 1.086 × 10^21 acidic protons.

Learn more: brainly.com/question/16672114

7 0
2 years ago
Select the statement(s) that explain(s) the relationship between the arrangement of elements by size and first ionization energy
kow [346]

c. A full s subshell is able to shield a newly filled p subshell from the nucleus, making the first electron in a p subshell easy to remove.

Explanation:

From the given options, a full s-sublevel is able to shield a newly filled p-subshell from the nucleus thereby making the first electron in a p-subshell easy to remove is correct.

What is ionization energy?

Ionization energy is a measure of the readiness of an atom to lose an electron.

First ionization energy is the energy required to remove the most loosely held electron in the gas phase.

The size of an atom/element depends on the number of electrons it contains. The more the electrons, the larger its size.

  • The larger an atom becomes the lesser the ionization energy needed to remove the first electron from its outermost shell.

Electron - electron repulsion occurs when two electrons in the same sub-level repels one another.

Shielding effect is the ability of the inner electrons to protect the outer electrons from the pull of the nuclear charge.

In option C, a s-subshell has a greater shielding effect than the p,d and f sub-shell in that order.

A newly introduced electron in the p-sublevel will be loosely held and easier to remove.

Learn more:

First ionization energy brainly.com/question/2153804

#learnwithBrainly

8 0
2 years ago
Read 2 more answers
The angle between the hydrogen atoms in water (H2O) is slightly less than expected for a tetrahedral shape. This is because of t
const2013 [10]
<span>The angle is less than that of a tetrahedral shape because of the lone pairs from oxygen. Using VESPR theory would show that the lone pairs from oxygen would interfere with the electron shells of the two hydrogen molecules.</span>
4 0
2 years ago
Read 2 more answers
Which is the correctly balanced chemical equation for the reaction of KOH and H2SO4? Upper K upper O upper H right arrow upper H
sertanlavr [38]

Answer :

The balanced chemical reaction will be,

H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.

If the amount of atoms of each type on the left and right sides of a reaction differs then to balance the equation by adding coefficient in the front of the elements or molecule or compound in the chemical equation.

The coefficient tell us about that how many molecules or atoms present in the chemical equation.

When sulfuric acid react with potassium hydroxide then it react to give potassium sulfate and water as a product. This reaction is known as acid-base reaction.

The balanced chemical reaction will be,

H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O

4 0
2 years ago
Read 2 more answers
Other questions:
  • A flask of fixed volume contains 1.00 mole of gaseous carbon dioxide and 88.0 g of solid carbon dioxide. the original pressure a
    8·2 answers
  • Consider the reaction 2Al(OH)3(s)→Al2O3(s)+3H2O(l) with enthalpy of reaction ΔHrxn∘=21.0kJ/mol What is the enthalpy of formation
    6·2 answers
  • Dry air is 78.08% nitrogen, 20.95% oxygen and 0.93% argon with the 0.04% being other gases. if the atmospheric pressure is 760.0
    8·2 answers
  • In this experiment, 0.170 g of caffeine is dissolved in 10.0 ml of water. the caffeine is extracted from the aqueous solution th
    12·1 answer
  • A chemist is working on a reaction represented by this chemical equation:
    12·2 answers
  • The initial temperature of the water in a constant-pressure calorimeter is 24°C. A reaction takes place in the calorimeter, and
    5·2 answers
  • Pesticide concentrations in the Rhine River between Germany and France between 1969 and 1975 averaged 0.55 mg/L of hexachloroben
    7·1 answer
  • Three structural isomers have the formula C5H12.C5H12. Draw and name the isomers using IUPAC names. Draw the isomer with five ca
    12·1 answer
  • ) Do you think the pH of 1,0 M tri-methyl ammonium (CH3)3NH+, pKa = 9.80, will be higher or lower than that of 1.0 M phenol, C6H
    9·1 answer
  • A hydrogen filled balloon has a bolume of 8.3 L at 36 C and 751 torr. How many moles of hydrogen are inside the balloon?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!