Answer:
Approximately [tex](-348\; {\rm J})[/tex], assuming that the bike was on level ground.
Explanation:
If an object of mass [tex]m[/tex] is moving at a speed of [tex]v[/tex], the kinetic energy of that object would be [tex](1/2)\, m\, v^{2}[/tex].
At a speed of [tex]v = 3.84\; {\rm m\cdot s^{-1}}[/tex], the kinetic energy of the bike and the cyclist- combined- would be:
[tex]\begin{aligned} &\frac{1}{2}\, m\, v^{2} \\=\; &\frac{1}{2}\times 53.0\; {\rm kg} \times (3.84\; {\rm m\cdot s^{-2}})^{2} \\ \approx \; & 390.76\; {\rm J}\end{aligned}[/tex].
At a speed of [tex]v = 1.27\; {\rm m\cdot s^{-1}}[/tex], the kinetic energy of the bike and the cyclist- combined- would be:
[tex]\begin{aligned} &\frac{1}{2}\, m\, v^{2} \\=\; &\frac{1}{2}\times 53.0\; {\rm kg} \times (1.27\; {\rm m\cdot s^{-2}})^{2} \\ \approx \; &42.741 \; {\rm J}\end{aligned}[/tex].
The energy change was approximately:
[tex]390.76\; {\rm J} - 42.741\; {\rm J} \approx 348\; {\rm J}[/tex].
If the bike was on level ground, the friction on the bike and the cyclist would have done a work of [tex](-348\: {\rm J})[/tex] to reduce the kinetic energy of the bike and the cyclist by that amount.
Answer: C) -348J
Explanation:
42.741 - 390.76 (the kinetic energy of the two speeds) is equal to -348.
If i apply mascara on a roller coaster, will my eyelashes fly off or get ruined?
(42)What is the speed of sound in air at a temperature of 15°C?
Answer:
340 m/s
At the temperature of 15 degrees Celsius, the velocity of sound is about 340 m/s in air.
Which optical device can focus light to a point through reflection?
Answer:
A
Explanation:
did the quiz
Answer:
A
Explanation:
A 740 kg car traveling 19 m/s comes to a complete stop in 2.0 s. What is the force exerted on the car during this stop?
Answer:
Force exerted on the car is 7030 N.
Explanation:
It is given that,
Mass of the car, m = 740 kg
Initial speed of the car, u = 19 m/s
Final speed of the car, v = 0
Time taken, t = 2 s
Let F is the force exerted on the car during this stop. We know that it is equal to the product of force and acceleration. Mathematically, it is given as :
F=m\times \dfrac{v-u}{t}F=m×tv−u
F=740\times \dfrac{0-19}{2}F=740×20−19
F = -7030 N
So, the force exerted on the car during this stop is 7030 N. Hence, this is the required solution.
Sound waves move the most quickly through which materiel?
A. Water
B. Iron
C. Milk
D. Air
Danielle is doing some diy. she uses a 1.2kw electric saw for 20 minutes and then a 1000w electric sander for half an hour. which job is the more expensive in terms of electricity used - sawing or sanding?
Based on the calculations, the electric sander (sanding) is the more expensive in terms of electricity used.
How to determine the more expensive?Mathematically, the quantity of energy consumed by an electrical device can be calculated by using this formula:
Energy consumption = power × time
For the electric saw, we have:
Power = 1.2 kW = 1.2 × 1000 = 1,200 Watts.Time = 20 minutes.Substituting the given parameters into the formula, we have;
Energy consumption = 1,200 × 20
Energy consumption = 24,000 Joules.
For the electric sander, we have:
Power = 1000 Watts.Time = half-hour = 30 minutes.Substituting the given parameters into the formula, we have;
Energy consumption = 1,000 × 30
Energy consumption = 30,000 Joules.
Therefore, the electric sander (sanding) is the more expensive in terms of electricity used.
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Answer: sanding
Explanation:
Energy used by saw = power × time = 1,200W × 1,200s = 1,440,000J.
Energy used by sander = power × time = 1,000W × 1,800s = 1,800,000J.
The sander uses more energy.
How long does 100m long train take a cross a bridge of length 4.9 km at a speed of 50m/s
Answer:
it would take 100s for the train to crossthe bridge
A 6kg block starts from rest against a spring with a spring constant of 500N/m that is compressed by a distance of 2m. The ground is frictionless. What will be the velocity of the block leaving the spring?
The velocity of the block leaving the spring is determined as 18.26 m/s.
Velocity of the block
The velocity of the block leaving the spring is calculated from the principle of conservation of energy.
K.E = Ux
¹/₂mv² = ¹/₂kx²
v² = kx²/m
v² = (500 x 2²)/6
v² = 333.33
v = √333.33
v = 18.26 m/s
Thus, the velocity of the block leaving the spring is determined as 18.26 m/s.
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The diagram shows two sets of vectors that result in a
single vector.
50 m
200 m
100 m
R
250 m
What are the first two steps for finding the magnitude
of the resultant vector?
find the square of the first horizontal vector and the
square root of the first vertical vector
find the square root of the first horizontal vector and
the square root of the second horizontal vector
find the sum of the two horizontal vectors and the
sum of the two vertical vectors
find the difference between the two horizontal
vectors and the difference between the two vertical
vectors
The first two steps for finding the magnitude of the resultant vector is find the sum of the two horizontal vectors and the sum of the two vertical vectors.
Resultant of two vectorsThe resultant of two vectors is determined from Pythagoras theorem is as shown below.
R² = a² + b²
First two steps of finding a resultant vectorsfind the sum of the two horizontal vectors and the sum of the two vertical vectors.Thus, the first two steps for finding the magnitude of the resultant vector is find the sum of the two horizontal vectors and the sum of the two vertical vectors.
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A locomotive (toy) travels at a velocity of 25 m/s for 10 s, then at 10 m/s for 5 minutes. What is the total distance covered?
A).3250m B). 4257 m C). 5200 D). The answer is not given
The total distance covered by the locomotive (toy) during the first and second journey is 10500 meters.
D) The answer is not given in the Options.
What is the total distance covered?Note that: Speed/velocity is distance traveled per unit time.
Speed = Distance ÷ time
Distance = velocity × time
Given that;
For the first journey,
velocity v = 25m/selapsed time t = 5min = (5×60)s = 300sFor the second journey,
velocity v = 10m/selapsed time t = 5min = (5×60)s = 300sDistance covered in the first journey
Distance = velocity × time
Distance = 25m/s × 300s
Distance = 7500m
Distance covered in the second journey
Distance = velocity × time
Distance = 10m/s × 300s
Distance = 3000m
Total distance covered will be;
Total Distance = Distance covered in the first journey + Distance covered in the second journey
Total Distance = 7500m + 3000m
Total Distance = 10500m
Therefore, the total distance covered by the locomotive (toy) during the first and second journey is 10500 meters.
D) The answer is not given in the Options.
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Ben walks 500 meters from his house to the corner store. He then walks back toward his house, but continues 200 meters past his house to talk to a neighbor. It takes Ben 17 minutes from the time he leaves his house until he stops to talk to his neighbor.
Considering the definition of velocity, the average velocity of Ben is 0.3 [tex]\frac{meters}{second}[/tex].
Definition of velocityVelocity is a physical magnitude that relates the displacement of an object, the time it takes to make this change in position and direction.
Because the speed also considers the direction in which the displacement of an object occurs, it is considered a vector magnitude.
So, the velocity can be defined as the amount of space traveled per unit of time with which a body moves, considering the direction, and can be calculated using the expression:
[tex]velocity=\frac{distancetraveled}{time}[/tex]
Velocity has units of [tex]\frac{distance}{time}[/tex], such as [tex]\frac{meters}{second}[/tex] or [tex]\frac{meters}{minute}[/tex], and includes direction of travel.
SummaryBen walks 500 meters from his house to the corner store. He then walks back toward his house, but continues 200 meters past his house to talk to a neighbor.
So, you know:
Distance traveled= distance from the start-point to the end-point= 500 - 200= 300 meters from Ben's house to the neighbor.Time= 17 minutes= 1020 seconds (being 1 minute= 60 seconds).Replacing in the definition of velocity:
[tex]velocity=\frac{300 meters}{1020 seconds}[/tex]
Solving:
velocity= 0.3 [tex]\frac{meters}{second}[/tex]
Finally, the average velocity of Ben is 0.3 [tex]\frac{meters}{second}[/tex].
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Which statement describes the magnetic field inside a bar magnet?
O It points from north to south.
• It points from south to north.
O It forms loops inside the magnet.
• There IS no field within the magnet.
The statement that describes the magnetic field inside a bar magnet is as follows: it points from north to south.
What is a bar magnet?A bar magnet is a permanent magnet of rectangular shape.
A magnet generally possess a magnetic field, which is a condition in the space around a magnet which there is a detectable magnetic force and the presence of two magnetic poles.
A bar magnet like every other magnet possesses a magnetic field that points from the north pole to the south pole.
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What can you infer about the changes in the environment over time at the mystery fossil dig site? Record your inferences in the spaces provided.
Describe the environment in Egypt before the mystery fossil organism emerged.
the fossil informed us about the climatic and geographical changes that occurs in the environment over time.
What the mystery fossil dig site informed us about environment?We can infer about the climate and geographical changes in the environment over time at the mystery fossil dig site because the fossil provides us information about the climatic condition as well as the geography of land when this fossil organism were alive.
So we can conclude that the fossil informed us about the climatic and geographical changes that occurs in the environment over time.
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The diameter of the Earth is 12.7 x 10 6 m. The diameter of Mars is 6800 km.
The difference in the diameters of the two planets is:
Answer:
5.9 × 10⁶m
Explanation:
The diameter of the Earth is 12.7 ×10⁶m.We have to convert the diameter of the mars in the same exponent as that of the earth so that we can easily subtract.The diameter of mars = 6800km = 6800 × 10³ m = 6.8 × 10⁶mNow we can subtract the diameters.The difference between the diameters = (The Diameter of Earth - The diameter of Mars)= 12.7×10⁶ - 6.8 × 10⁶
= 5.9 × 10⁶m
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A 500 N weight is hung at the middle of a rope attached to two buildings at the same level. If the breaks in the tension exceed 1800 N, what is the minimum angle the rope can make with the horizontal?
Not sure what you mean by "breaks in the tension" but I suspect you mean the rope will come apart if the tension in the rope exceeds 1800 N.
In the free body diagram for the 500 N weight, we have a figure Y with the net force equations
• horizontal net force:
∑ F[hor] = T₁ cos(θ) - T₂ cos(θ) = 0
• vertical net force:
∑ F[ver] = T₁ sin(θ) + T₂ sin(θ) - 500 N = 0
From the first equation, it follows that T₁ = T₂, so I'll denote their magnitude by T alone. From the second equation, we have
2 T sin(θ) = 500 N
and if the maximum permissible tension is T = 1800 N, it follows that
sin(θ) = (500 N) / (3600 N) ⇒ θ = arcsin(5/36) ≈ 7.9°
is the smallest angle the rope can make with the horizontal.
what is the direction of the magnetic force on the charge
Answer: A
Explanation:
How does the value of gravity vary as you go:
i. above the earth surface?
ii. below the earth surface?
Answer:
Gravity changes with altitude. as we know The gravitational force is proportional to 1/R2, where R is your distance from the center of the Earth.
eg. The radius of the Earth at the equator is 6400 kilometers.
Let's say you were in a jet at the equator that was 40 kilometers high above the earth's surface.
may be helpfull
When object 1 came into contact with object 2, object 2 got warmer. what can be concluded about the objects before they came into contact with each other? object 2 did not have thermal energy. object 1 had faster-moving particles. object 1 had less thermal energy. object 2 had fewer particles.
The statement that is true regarding the objects is that object 1 had faster-moving particles, which is option 2. Details about matter can be found below.
What is matter?Matter can be defined as any particle that has weight and occupies space.
Certain particles are present in the different states of matter. According to this question, when object 1 came into contact with object 2, object 2 got warmer.
This suggests that the particles in the object 1 is moving faster due to an increase in temperature.
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Answer: b
Explanation: i took the quiz
Try to solve this question:
Explanation:
w = mg
on earth
w = mg
w = 60 × 9.8 = 588 N
on moon
w = mg
w = 60 × 1.6 = 96 N
on Mars
w = mg
w = 60 × 3.7 = 222 N
In this question,we solve it using the formulae below:
W=mg.
So to find the weight of the object in 1.Earth.Enter the given data on formula:
W=mg
W=60×9.8
W= 588N.2.Weight on the moon.
W=mg
W=60×1.6
W=96N3.Weight on Mars.
W=mg
W=60×3.7
W=222N.A boat going from salt water (sg = 1. 03) to fresh water (sg=1. 0) sinks 7. 82cm and after burning 72,730kg of coal rises up by 15. 24cm. Find the original displacement of the boat in seawater in kn
The original displacement of the boat in seawater in km is 7.42 x 10⁻⁵ km.
What is displacement?The shortest path traveled by any particle during its motion.
A boat going from salt water to fresh water sinks 7. 82cm. After burning coal, the boat rises up by 15. 24cm.
Displacement = 15.24 -7.82 = 7.42 cm
1cm = 10⁻⁵ km
So, 7.42 cm =7.42 x 10⁻⁵ km
Thus, the original displacement is 7.42 x 10⁻⁵ km.
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why is it difficult to climb on a mountain through vertical path than a curved path
Answer: For less steep slope, less power is needed by the vehicle. The concept is that it will be easier for one to exert less control and that too for a more extended period. So the roads of the mountains are always made curvy and not straight.
Which word is described by this statement? This is the top of the volcano where sulfur-filled gasses and lava come out.
Answer:
I believe it is crater.
On a hot day, the deck of a small ship reaches a temperature of 48
17.0°C seawater on the deck to cool it down. During the cooling, 3,710,000 J are transferred to the
seawater from the deck. Assume no energy or mass is lost from the system. Use c = 3,930 J/kg°C for
seawater.
Calculate the final temperature of the seawater-deck system.
Write your answer rounding to the nearest tenth.
The final temperature of the seawater-deck system is 990°C.
What is heat?The increment in temperature adds up the thermal energy into the object. This energy is Heat energy.
The deck of a small ship reaches a temperature Ti= 48.17°C seawater on the deck to cool it down. During the cooling, heat Q =3,710,000 J are transferred to the seawater from the deck. Specific heat of seawater= 3,930 J/kg°C.
Suppose for 1 kg of sea water, the heat transferred from the system is given by
3,710,000 = 1 x 3,930 x (T - 48.17)
T = 990°C to the nearest tenth.
The final temperature of the seawater-deck system is 990°C.
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Base your answers to questions 27 through 30 on the information below and on your knowledge of physics.
The Great Nebula in the constellation Orion consists primarily of excited hydrogen gas.
The electrons in the atoms of excited hydrogen have been raised to higher energy levels. When these atoms release energy, a frequent electron transition is from the excited n = 3 energy level to the n = 2 energy level, which gives the nebula one of its characteristic colors.
27 Determine the energy, in electronvolts, of an emitted photon when an electron transition from n=3 to n = 2
occurs.
28 Determine the energy of this emitted photon in joules.
29 Calculate the frequency of the emitted photon. [Show all work, including the equation and substitution with units.]
30 Identify the color of light associated with this photon.
27. The energy , in electronvolts, of an emitted photon when an electron transition from n=3 to n = 2 is -1.89 eV.
28. The energy of this emitted photon in joules is -3.0278 x 10⁻¹⁹ Joules.
29. The frequency of the emitted photon is 4.572 x 10¹⁴ Hz.
30. The color of light associated with this photon is Red.
What is frequency?It is the number of oscillations per second of the sinusoidal wave.
Given is the Great Nebula in the constellation Orion consists primarily of excited hydrogen gas.
The electrons in the atoms of excited hydrogen have been raised to higher energy levels. When these atoms release energy, a frequent electron transition is from the excited n = 3 energy level to the n = 2 energy level, which gives the nebula one of its characteristic colors.
27. The energy of transition between n = 3 to n = 2 is
E = R h e (1/n₁² - 1/n₂²)
where R = Rydberg constant and h = Planck's constant.
Substitute the values, we get
E = 1.0974 x 10⁻⁷ x 6.626 x 10⁻³⁴ x 1.6 x 10⁻¹⁹ (1/3² - 1 /2²)
E = -1.89 eV
28. Energy in joules can be obtained by multiplying 1.6 x 10⁻¹⁹ . So we have
E = -1.89 eV x 1.6 x 10⁻¹⁹ J/eV
E = -3.0278 x 10⁻¹⁹ Joules
29. Wavelength associated with the photon emitted is
1/λ = R (1/n₂² - 1/n₁² )
Substitute the values, we get
1/ λ = 1.524 x 10⁶ /m
The frequency is related to the wavelength as
f = c/λ where c = speed of light
f = 3 x 10⁸ x 1.524 x 10⁶
f = 4.572 x 10¹⁴ Hz
30. The color of light associated with the photon of calculated frequency is Red.
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Calculate the power of a person that does 8kJ of work in 4 hours
[tex]\text{Power,}~ P = \dfrac{\text{Work done}}{\text{Time}}\\\\\\~~~~~~~~~~~~~=\dfrac{8 \times 1000~J}{4 \times 3600~ s}\\\\\\~~~~~~~~~~~~~~=\dfrac{80}{144}\\\\\\~~~~~~~~~~~~~~=0.56~ W[/tex]
Answer:
Explanation:
Energy used is power multiplied by time.
Power is energy used divided by time
8 kj is 8000 j
4 hours is 240 minutes
240 minutes is 14400 seconds
8000j divided by 14400 is 0.55 recurring, measured in watts
A model train running on an inclined track is part of a closed system that has
316 J of mechanical energy. If the kinetic energy of the train decreases from
314 J to 250 J, what happens to the gravitational potential energy of the
system?
A. It decreases from 66 J to 2 J.
B. It decreases from 316 J to 314 J.
SMIT
OC. It increases from 2 J to 66 J.
D. It increases from 316 J-to 564 J.
If the kinetic energy of the train decreases from 314 J to 250 J, the gravitational potential energy of the system It increases from 2 J to 66 J.
What is conservation of mechanical energy?The principle of conservation of mechanical energy states that the total mechanical energy of a system is always constant. This means that the sum of the potential and the kinetic energy does not change.
Thus, if the kinetic energy of the train decreases from 314 J to 250 J, the gravitational potential energy of the system It increases from 2 J to 66 J.
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What is the most likely outcome? it will become a permanent magnet because the domains will remain aligned. it will become a temporary magnet because the domains will remain aligned. it will become a permanent magnet because the domains will easily realign. it will become a temporary magnet because the domains will easily realign.
The likely outcome when a magnetically soft material is placed in a strong magnetic field is that it will become a temporary magnet because the domains will easily realign.
What is a magnet?A magnet is a material whose magnetic domains are properly aligned. These materials are able to attract other materials that are magnetizable.
Hence, the likely outcome when a magnetically soft material is placed in a strong magnetic field is that it will become a temporary magnet because the domains will easily realign.
Missing parts:
A magnetically soft material is placed in a strong magnetic field. What is the most likely outcome?
a. It will become a permanent magnet because the domains will remain aligned.
b. It will become a temporary magnet because the domains will remain aligned.
c. It will become a permanent magnet because the domains will easily realign.
d. It will become a temporary magnet because the domains will easily realign.
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Answer: D or It will become a temporary magnet because the domains will easily realign.
Explanation: Taking the quiz!
Hello people ~
A current passes through a resistor. If K₁ and K₂ represent the average kinetic energy of the conduction electrons and the metal ions respectively then
(a) K₁ < K₂
(b) K₁ = K₂
(c) K₁> K₂
(d) any of these three may occur
Answer:
K1>K2
Explanation:
The main reason behind this is law of conservation of momentum
Momentum can neither be created nor endorsed.But
the factor drift velocity affects the scenario.
Drift velocities of electrons is way more than velocities of ions so
K1 is greater than K2Option C
Question 1 of 10
What is the wavelength of a wave with a frequency of 262 Hz and a speed of
343 m/s?
O A. 1.3 m
OB. 89,866 m
O C. 1.11 x 10-5 m
O D. 0.76 m
SUBMIT
Answer:
V = λ f (wavelength * frequency)
λ = V / f = 343 m/s / 262 / s = 1.3 m
What explains the key difference between a bomb calorimeter and a coffee cup calorimeter?.
The key difference between a bomb calorimeter and a coffee cup calorimeter is high temperature.
What is bomb calorimeter?A bomb calorimeter is an apparatus that can measure heats of combustion, used in various applications such as calculating the calorific value of foods and fuels.
What is coffee cup calorimeter?A coffee cup calorimeter is a cup used to provide insulation when materials are mixed inside of it.
Difference between the two calorimeterThe coffee cup calorimeter can't be used for high-temperature reactions, either, because they would melt the cup. A bomb calorimeter is used to measure heat flows for gases and high-temperature reactionsLearn more about calorimeter here: https://brainly.com/question/1407669
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