The velocity at the bottom of the swing is [tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]. The time it took the child to reach the river is 0.62 seconds.
The objective of this question is to determine:
The expression for the velocity of the child at the bottom of the swing.Suppose the child lets go at the bottom of the swing, how long does she take to reach the river at t seconds.At the bottom of the swing, there is an equal change in both the Kinetic energy as well as the potential energy and the expression can be computed as:
[tex]\mathbf{\dfrac{1}{2}mv^2 = mg (h -d)}[/tex]
[tex]\mathbf{\dfrac{v^2}{2}= g (h -d)}[/tex]
[tex]\mathbf{v^2= 2gh -2gd}[/tex]
[tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]
According to the second equation of motion;
[tex]\mathbf{S = ut +\dfrac{1}{2}at^2}[/tex]
where;
distance s = d = 1.9 macceleration due to gravity = 9.8 m/s²initial velocity (u) = 0∴
[tex]\mathbf{1.9 = 0(t) +\dfrac{1}{2}(9.8) t^2}[/tex]
[tex]\mathbf{1.9 = \dfrac{1}{2}(9.8) t^2}[/tex]
[tex]\mathbf{t^2 =\dfrac{1.9\times 2}{9.8} }}[/tex]
[tex]\mathbf{t = \sqrt{\dfrac{1.9\times2}{9.8}}}[/tex]
[tex]\mathbf{t =0.62 \ s}[/tex]
Therefore, we can conclude that the velocity at the bottom of the swing is [tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]. The time it took the child to reach the river is 0.62 seconds.
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A block of mass m is initially at rest on a rough horizontal surface when a constant force F is exerted on it, as shown. The block accelerates to the right and is moving with speed v once it has moved a distance d. Which of the following equations can be used to solve for the force of friction exerted on the block by the surface?
The equations that can be used to solve for the force of friction exerted on the block by the surface is F- f = mv² / d
The constant force F is exerted on the block of mass and it accelerates with a speed, v and covering a distance of d in the direction of the force. The force of friction is an opposing force to the applied force.
Therefore,
using Newtons third law
F - f = ma
a = v/t
t = d/v
F - f = m × v / t
F- f = m × [tex]\frac{v}{\frac{d}{v} }[/tex]
F- f = m × v²/d
Therefore,
F- f = mv² / d
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What does 1 N = ? please I need help?
[tex]1~N = 1~ \text{kg~ms}{^{-2}[/tex]
1 N = 1 kg × m/s²
One Newton is equal to 1 kilogram multiplied by meter by second squared.
_____
Hope it helps ⚜
What is the kinetic energy of a 2,000-kg boat moving at 5.0 m/s?
Answer:
25kJ
Explanation:
K = 1/2 mv^2 = 1/2 x 2000kg x (5.0m/s)^2
= 25 x 10^3 J = 25kJ
Which state of matter has molecules that move the most?
liquid
solid
gas
They are all the same.
Answer:
gas
Explanation:
in gaseous state molecules move the most because force of attraction between atoms are least in gaseous state
Best definition of an electromagnetic wave?
A) an electromagnetic wave is a longitudinal wave with electricity
B) an electromagnetic wave is a mechanical wave
C) an electromagnetic wave is a transversal wave that has electrical and magnetic properties
Answer:
Longitudinal and mechanical waves require a medium to support their transmission:
C) is the correct answer
A 46.5-kg ball has a momentum of 57.2 kg m/s. What is the ball's speed?
Answer:
1.23 m/s
Explanation:
p=mv
57.2 = 46.5v
v= 57.2/46.5
v= 1.23
If you want to verify your answer, just insert the value of v in the equation.
The Kentucky Derby is one of the most exciting horse races run every year. In 1973, the horse Secretariat set a record that still stands. This 500-kg horse ran the 2000-m track in 120 s. What was Secretariat’s average kinetic energy? (1 kJ = 1000 J)
Need answers with explanaitions please
A. 4.2 kJ
B. 8.3 kJ
C. 69.0 kJ
D. 139.0 kJ
Answer:
C.69 kJ
Explanation:
kinetic energy
[tex] = 1 \div 2mv {}^{2} [/tex]
What force causes an automobile to move.
Answer:
Thrust
Explanation:
Thrust is the force that causes a car to move in the direction that it wants to.
When astronomers carefully examine the planets found by Kepler and draw conclusions from the Kepler sample, what do they conclude about planets the size (radius) of Earth
Given what we know about the Kepler space program, we know that the astronomers discovered that Earth-sized planets are more common than we imagined.
Kepler was launched with the intention of getting a closer look at other planets outside of our solar system using enhanced photometrics.
The idea behind this launch was to discover more Earth-sized planets, preferably within the habitable zone of their central star.
What this mission showed astronomers, is that Earth-sized planets are more common than we could have imagined, Kepler proved this by finding over 2,662 planets to date.
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What happens when you want to move the boat forward? You pull the oars toward yourself.Explain why you do this.
Answer:
You pull on the oars. By the third law, the oars push back on your hands, but that’s irrelevant to the motion of the boat. The other end of each oar (the blade) pushes against the water. By the third law, the water pushes back on the oars, pushing the boat forward.
Examples of energy conversion in daily life
Answer:
Energy conversion, also termed as energy transformation, is the process of changing one form of energy into another. Energy conversion occurs everywhere and every minute of the day. There are numerous forms of energy like thermal energy, electrical energy, nuclear energy, electromagnetic energy, mechanical energy, chemical energy, sound energy, etc. On the other hand, the term Energy Transformation is used when energy changes forms from one form to another. Whether the energy is transferred or transformed, the total amount of energy doesn’t change and this is known as the Law of Conservation of Energy.
Explanation:
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how is pure salt obtained from the sea water ?describe in brief
Answer:
Evaporation
Explanation:
Evaporation
Answer:
Salt from sea water is obtained by the process of evaporation. ... The sea water evaporates due to the sun's heat and solid salt is left behind. The left salt is collected and refined to get purified salt. Hence, salt is obtained from sea water by evaporation.
A 1300-kg car is traveling with a speed of 16.0 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 38.9 m?
Answer:
F=ma,a=0.329m/second squared,m=1300kg,F=1300*0.329=4277N
Calculate the weight of an object that displaces 3 m2 of water and exerts a pressure of 500 Pa (500 N/m ).
The weight of the object from the information provided in the question is 1500 N.
We know that pressure = Force/area. We have the following information from the question;
Pressure =500 Nm-2
Area = 3 m2
Hence;
Force = Pressure × area
Force = 500 Nm-2 × 3 m2
Force = 1500 N
Hence, the weight of the object is 1500 N
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which statement about moist air moving over a mountain is correct?
Answer:
Explanation:
The orographic effect occurs when air masses are forced to flow over high topography. As air rises over mountains, it cools and water vapor condenses. As a result, it is common for rain to be concentrated on the windward side of mountains, and for rainfall to increase with elevation in the direction of storm tracks.
discrete packets of kinetic energy in light are called
Answer:
Photons
Explanation:
I just know
Discrete packets of kinetic energy in light are called photons. Photons are fundamental particles of light and electromagnetic radiation. The correct answer is photons.
Photons are fundamental particles of light and electromagnetic radiation. They carry energy in discrete quantities, known as quanta or packets, and exhibit both wave-like and particle-like properties.
The energy of a photon is directly proportional to its frequency, and inversely proportional to its wavelength. When light interacts with matter, it can transfer its energy to the particles it interacts with, leading to various phenomena such as absorption, reflection, and emission.
Therefore, Discrete packets of kinetic energy in light are called photons.
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If acceleration of a body starting from the rest is 0.5m/s^2 how long will it take the body to travel 400m(if u are genius answer this)
Answer:
10s
Explanation:
If you eat cheese are you 1 percent cheese?
Answer:
No. Exactly what you eat doesn’t make up your internal structure.
:)
Answer:
Explanation:
Light cheeses are less than 20 %, low fat cheeses are 20 to 30%, fat cheeses are 50 to 60%, double-cream cheeses are at least 60% and triple-cream cheeses are at least 75 %.
Select the correct answer.
What represents the value of the second-best alternative that a person gives up when making a choice?
OA. marginal spending
ОВ.
marginal benefit
OC. opportunity cost
OD. marginal cost
The answer should be opportunity cost
The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at 3. The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at atmospheric pressure, would have to be admitted into the space to cause the column of the mercury
to drop to 59 cm?
The ideal gas equation and the pressure in barometer allows us to find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The variation of the volume is: ΔV = 7.67 cm³
Pressure is defined by the relationship between force and area.
P = F / A
The ideal gas equation establishes a relationship between pressure, volume, and temperature of an ideal gas.
PV = nR T
Where P is pressure, V is volume, and T is temperature.
Let's write this equation for two points assuming that the temperature has not changed.
P₀ V₀ = P₁ V₁
V₁ = [tex]\frac{P_o}{P_1} \ V_o[/tex] (1)
The subscript "o" is used for the start point and the subscript "1" for the end point.
The pressure in a barometer is:
P = ρ g y
They indicate the initial height of the barometer y₀=75 cm, the distance from empty space y'₀ = 9 cm and the final height of the barometer y₁ = 59 cm.
The volume of the cylinder is
V = π r² y
Let's calculate the initial volume.
V₀ = π 1 9
V₀ = 28.27 cm³
We substitute in equation 1.
V₁ = [tex]\frac{\rho \ g \ y_o}{\rho \ g \ y_1} \ V_o[/tex]
V₁ = [tex]\frac{y_o}{y_1} \ V_o[/tex]
Let's calculate.
V₁ = [tex]\frac{75}{59} \ 27.27[/tex]
V₁ = 35.94 cm³
The volume to be incremented is
ΔV = V₁ - V₀
ΔV = 35.94 - 28.27
ΔV = 7.67 cm³
Using the ideal gas equation and the pressure in barometer we can find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The change of the volume is: ΔV = 7.67 cm³
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Without friction, what is the mass of an ball accelerating at 1.8 m/sec2 to which an
an unbalanced force of 42 Newtons has been applied?
A 75.60 kg
B 00.04 kg
C 23.33 kg
D 43.80 kg
Answer:
23.33 kgExplanation:
The mass of the object can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{42}{1.8} = 23.3333... \\ [/tex]
We have the final answer as
23.33 kgHope this helps you
Answer:
[tex]\boxed {\boxed {\sf C. \ 23.33 \ kg}}[/tex]
Explanation:
According to Newton's Second Law of Motion, force is the product of mass and acceleration.
[tex]F=ma[/tex]
The mass of the ball is unknown. The ball is accelerating at 1.8 meters per second squared. An unbalanced force of 42 Newtons is applied to the ball.
Convert the units of force. 1 Newton is equal to 1 kilogram meter per second squared, so our answer of 42 Newtons is equal to 42 kg*m/s².
F= 42 kg*m/s² a= 1.8 m/s²Substitute the values into the formula.
[tex]42 \ kg*m/s^1 = m * 1.8 \ m/s^2[/tex]
We are solving for the mass, so we must isolate the variable m. It is being multiplied by 1.8 meters per second squared. The inverse operation of multiplication is division. Divide both sides by 1.8 m/s².
[tex]\frac {42 \ kg*m/s^2}{1.8 \ m/s^2} = \frac{a*1.8 \ m/s^2}{1.8 \ m/s^2}[/tex]
[tex]\frac {42 \ kg*m/s^2}{1.8 \ m/s^2} =m[/tex]
The units of meters per second squared cancel.
[tex]\frac {42 \ kg}{1.8 } =m[/tex]
[tex]23.3333333 \ kg=m[/tex]
Round to the hundredth place. The 3 in the thousandth place tells us to leave the 3 in the hundredth place.
[tex]23.33 \ kg \approx m[/tex]
The mass of the ball is approximately 23.33 kilograms.
Analyze the effects on a passenger riding in a car traveling at
50 km/h that collides head-on with a solid object.
Without:
The passenger will get seriously injuredColliding with the windshield at 50km/hCould result in deathWith safety:
The seatbelt holds tge passengers body back so they dont collide with anythingTheir head is cushioned by the airbagThe passenger might get minor injuries but nothing serious will happen If a net force of 24 Newtons is applied on an object of mass 6
kilograms, what will be the acceleration of the object?
a 2 m/s2
b. 6 m/s2
C 10 m/s2
d 4 m/s2
Answer:
4 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question
f = 24 N
m = 6 kg
We have
[tex]a = \frac{24}{6} = 4 \\ [/tex]
We have the final answer as
4 m/s²Hope this helps you
5. An acrobat, starting from rest, swings freely on a trapeze of
length 3.7 m (Figure 6). If the initial angle of the trapeze is
48°, use the law of conservation of energy to determine
(a) the acrobat's speed at the bottom of the swing
(b) the maximum height, relative to the initial position, to
which the acrobat can rise
The energy conservation and trigonometry we can find the results for the questions about the movement of the acrobat are;
a) The maximum speed is v = 4.89 m / s
b) The maximum height is h = 1.22 m
The energy conservation is one of the most fundamental principles of physics, stable that if there are no friction forces the mechanistic energy remains constant. Mechanical energy is the sum of the kinetic energy plus the potential energies.
Em = K + U
Let's write the energy in two points.
Starting point. Highest part of the oscillation
Em₀ = U = m g h
Final point. Lower part of the movement
[tex]Em_f[/tex] = K = ½ m v²
Energy is conserved.
Emo = [tex]Em_f[/tex]
m g h = ½ m v²
v² = 2 gh
Let's use trigonometry to find the height, see attached.
h = L - L cos θ
h = L (1- cos θ)
They indicate that the initial angle is tea = 48º and the length is L = 3.7 m, let's calculate.
h = 3.7 (1- cos 48)
h = 1.22 m
this is the maximum height of the movement.
Let's calculate the velocity.
[tex]v= \sqrt{2 \ 9.8 \ 1.22}[/tex]
v = 4.89 m / s
In conclusion using the conservation of energy and trigonometry we can find the results for the questions about the movement of the acrobat are;
a) The maximum speed is v = 4.89 m / s
b) The maximum height is h = 1.22 m
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If you blow up a balloon, tie it off, and release it, it will fall to the ground.
Why does it fall instead of float?
NO LINKS YA FILTHY VERMINS
Answer:
carbon dioxide (what you are blowing up the balloon with) is a heavy gas. so when you fill the Balloon with it, the balloon will not float. helium is a light gas and floats. gravity takes another. part in this
The strength of the electric field 0. 5 m from a 6 µC charge is _______ N/C. (Use k = 8. 99 × 109 N•meters squared per Coulomb squared and round answer to the nearest whole number. ) 215760 539400 697976 512356.
The strength of the electric field at a distance of 0.5 m from a 6 μC punctual charge is 143,840 N/C.
We want to calculate the strength of the electric field 0.5 m (r) from a 6 μC charge (Q).
What is the electric field?The electric field (E) is a region around a charged particle or object within which a force would be exerted on other charged particles or objects.
We can calculate the electric field at some distance from a punctual charge using the following formula.
E = (k × Q) / r²
E = [(8.99 × 10⁹ N.m².C²) × (4 × 10⁻⁶ C)] / (0.5 m)² ≈ 143,840 N/C
where,
k is the Coulomb's law constant.The strength of the electric field at a distance of 0.5 m from a 6 μC punctual charge is 143,840 N/C.
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What happens in a nucleus during beta decay
The numbers of protons increases
The number of neutrons increases
The number of protons decrease
The number of protons plus the number of neutrons decreases
The number of protons plus the number of neutrons decreases
Beta decay occurs when, in a nucleus with too many protons or too many neutrons, one of the protons or neutrons is transformed into the other. In beta minus decay, a neutron decays into a proton, an electron, and an antineutrino: n Æ p + e - +.
a race car traveling at 44m/s slows at a constant rate to a velocity of 22m/s over 11 seconds , how far does it move during this time
find distance and acceleration
FAST PLEASE !!
Answer:
-1.2×10^2 m
I hope this helps you
I rode my bicycle to grandmother's house at 6 km/h in a flat road for 5 min before reach a hill. I went at 2 km/h up the hill for 3minutes. I met a friend and stopped to talk for 5 minutes. I went on at 2 km/h to my grandmother's house. Draw (plot) the v against t graph for this motion.
The graph can be plotted based on the given information which are given
in pairs (velocity and time), and which the coordinate pairs are formed.
Please find attached the required v against t graph created with MS ExcelReasons:
The given data are presented in a tabular form as follows;
[tex]\begin{tabular}{|c|c|c}\underline{Duration (Minutes)} & \underline{Speed (km/h)}\\0 - 5 &6 \\5 - 8&2\\8 -13&0&\\13- &2&\end{array}[/tex]
The velocity time graph can be plotted using the above table values on
MS Excel using the above table elaborated as follows;
[tex]\begin{tabular}{|c|c|c}\underline{Duration (Minutes)} & \underline{Speed (km/h)}\\0 &6 \\5&6\\5 &2\\8&2\\8&0\\13&0&\\13 &2&\end{array}[/tex]
The attached graph can then be created using the Insert → Chart menu
after selecting the data above inputted in the spreadsheet button on MS
Excel.
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If larger-diameter tires are mounted on the car instead, how will that affect the speedometer reading? The speedometer
Answer:
A speedometer is related to the number of complete revolutions.
A larger diameter tire will travel farther in one revolution.
N D = S where N is the number of revolutions and S the distance traveled
N = S / D so the speedometer will record less revolutions and less distance traveled if the diameter is increased and the distance traveled will be too small as compared to the actual distance traveled.