Answer:
the ratio of her final kinetic energy to her initial kinetic energy is 1.7.
Explanation:
Given;
initial angular speed, ω₁ = 5.9 rad/s
let her initial moment of inertia = I₁
her final moment of inertia [tex]I_2 = \frac{I_1}{1.7}[/tex]
Apply the principle of conservation of angular momentum to determine the final angular speed of the girl;
[tex]\omega_1I_1 = \omega_f I_2\\\\\omega_f = \frac{\omega _1 I_1}{I_2} \\\\\omega_f = \frac{5.9 \times I_1}{I_1/1.7} \\\\\omega = 5.9 \times 1.7 \\\\\omega_f = 10.03 \ rad/s[/tex]
The initial rotational kinetic energy is given as;
[tex]K.E_I = \frac{1}{2}I_1 \omega_I ^2[/tex]
The final rotational kinetic energy is given as;
[tex]K.E_f = \frac{1}{2}I_2 \omega_f ^2[/tex]
The ratio of her final kinetic energy to her initial kinetic energy is given as;
[tex]\frac{K.E_f}{K.E_I}= \frac{\frac{1}{2}I_2 \omega_f^2 }{\frac{1}{2} I_1\omega _1^2} \\\\\frac{K.E_f}{K.E_I}= \frac{I_2 \omega_f^2}{ I_1\omega _1^2} \\\\\frac{K.E_f}{K.E_I}= \frac{I_1/1.7 \times \omega_f^2}{ I_1 \times \omega _1^2} \\\\\frac{K.E_f}{K.E_I}= \frac{ \omega_f^2}{ 1.7 \omega _1^2} \\\\\frac{K.E_f}{K.E_I}= \frac{ (10.03)^2}{ 1.7(5.9)^2} = \frac{17}{10} = 1.7[/tex]
Therefore, the ratio of her final kinetic energy to her initial kinetic energy is 1.7.
a boat carving people more than its capacity is at risk of sinking, why?
Answer:
Explained below.
Explanation:
For a boat or any object to float on water, it's density must be less than that of water.
Now, when the maximum capacity of people to be carried by the boat is exceeded, it's possible that the maximum mass of people will also be exceeded depending on the mass of the people in the boat.
Now, we know that; density = mass/volume.
Thus, the higher the mass of the people, the higher the density and the higher the density, the more likely it is to be above that of water and the more likely it is to sink.
A right triangle has side lengths of 4 centimeters and 5 centimeters. What is the length of the hypotenuse?
O A. 3 cm
B. 4 cm
C. 5 cm
D. 41 cm
What is the solubility of KNO3 at 50°C?
45 grams
63 grams
70 grams
83 grams
Answer:
The solubility of KNO3 at 50 degrees C is 83 g/100 g water.
Explanation:
when u see the graph and by using graph reading techniques then u find the solubility.
You are riding in the passenger seat of a car as it goes around a tight turn. You slide across the seat to the passenger side door. Which statement below properly describes what happens? a. You are exerting a centripetal force on the car door. b. The door is exerting a centripetal force on you that balances the centrifugal force of the turn. c. The car seat is exerting a centripetal force on you, but not enough to keep you in place. d. The turn exerts a centrifugal force on you that throws you out toward the door. 2. An object is moving in a circle at a constant speed. From this you can be certain that a. There is at least one force acting on the object. b. There is no net force acting on the object. c. There are at least two forces acting on the object, which balance each other. d. There are at least two forces acting on the object, which do not balance each other. e. There must be more than two forces acting on the object.
Answer:
1. b. The door is exerting a centripetal force on you that balances the centrifugal force of the turn.
2. b. There is no net force acting on the object.
Explanation:
1. This is because as you move to the right due to the centrifugal force of the turn, a corresponding centripetal force acts on you due to the door which does not allow you fall out of the car since, the door is exerting a centripetal force on you that balances the centrifugal force of the turn.
So, the answer is b
2. This is because, since the object moves at a constant speed and thus does not accelerate, no net force can act on it since, a net force would imply that the object accelerates. Note that a constant speed does not imply that no force acts on it. It only shows that the resultant or net force is zero since the object does not accelerate.
So, there is no net force acting on the object.
So, b is the answer.
1. If a system is isolated, the total energy within that system is constant. Consider the case of a hot cup of coffee: when it cools down, the energy goes into the surrounding air, causing the air to warm. If the coffee and the air are placed in an isolated chamber, the total energy of the system (coffee + air) is constant because the energy lost by the coffee is exactly equal to the energy gained by the air.
The only way for the total energy of a system to change is when it is not isolated, meaning that external forces or sources of energy interact with the system. If we want to define a system where the total energy is conserved, which one of the choices below would be the best system to consider?
A. The person
B. The person and the Earth
C. The Earth
2. Based on your answer to Question 1, why doesn’t the total energy of the Earth-person system change when the person goes up to a new height, gaining potential energy?
Answer:
1. B. The person and the Earth
2. This is because the energy gained by the person equals the energy lost by the earth,
Explanation:
1.
B. The person and the Earth
This is because the person and the earth both represent a system. A system consists of more than one item. A system consists of two or more items interacting with each other.
2. This is because, the energy of an isolated system is conserved according to the second law of thermodynamics which states that in an isolated system, energy can neither be created nor destroyed. So, there is an exchange of energy between the person and the Earth. So, the energy gained by the person at the new height equals the energy lost by the earth. And thus, the total energy of the system remains constant.
A 20-kg child is on top of a slide was pushed down by his brother giving him an initial speed of 2 m/s down the slide. what is the child's speed at the bottom of the slide if the slide is 5 m high and 10m long and the force of friction between the child and slide is negligible?
Answer:
please find your answer in the attached picture, along with explanation.
Can you please help me ?
Answer:
Distance is 300 and displacement is 100
Explanation:
Distance= 100+100+100=300
Displacement=100
plz mark me as brainliest.
what is the meaning of love ? ...What is love?
Answer:
love is a feeling that you get for people that you care about.
Explanation:
Answer:
Love is a feeling of affection for someone, when you adore somebody.
I wish true love and soul mates were real ( •_•)
Why is a star an example of a good blackbody radiator?
A. It gives off a range of wavelengths of electromagnetic radiation
that depends on its temperature.
B. It absorbs a range of wavelengths of electromagnetic radiation
and gives off none.
c. It reflects most electromagnetic radiation instead of absorbing it.
D. It gives off only one wavelength of electromagnetic radiation.
Answer: A. It gives off a range of wavelengths of electromagnetic radiation that depends on its temperature.
Explanation: Quizzed
If you weigh 690 N on the earth, what would be your weight on the surface of a neutron star that has the same mass as our sun and a diameter of 15.0 km ? Take the mass of the sun to be ms = 1.99×1030 kg , the gravitational constant to be G = 6.67×10−11 N⋅m2/kg2 , and the free-fall acceleration at the earth's surface to be g = 9.8 m/s2 . Express your weight wstar in newtons.
Answer:
W' = 1.66 x 10¹⁴ N
Explanation:
First, we will calculate the mass:
[tex]W = mg[/tex]
where,
W = weight on earth = 690 N
m = mass = ?
g = acceleration due to gravity on earth = 9.8 m/s²
Therefore,
[tex]m = \frac{W}{g} = \frac{690\ N}{9.8\ m/s^2}\\\\m = 70.4\ kg[/tex]
Now, we will calculate the value of g on the neutron star:
[tex]g' = \frac{GM}{R^2}[/tex]
where,
g' = acceleration due to gravity on the surface of the neutron star = ?
G = Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
M = Mass of the Neutron Star = 1.99 x 10³⁰ kg
R = Radius of the Neutron Star = 15 km/2 = 7.5 km = 7500 m
Therefore,
[tex]g' = \frac{(6.67\ x\ 10^{-11}\ N.m^2/kg^2)(1.99\ x\ 10^{30}\ kg)}{(7500\ m)^2}\\\\g' = 2.36\ x\ 10^{12}\ m/s^2[/tex]
Therefore, the weight on the surface of the neutron star will be:
[tex]W' = mg'\\W' = (70.4\ kg)(2.36\ x\ 10^{12}\ m/s^2)[/tex]
W' = 1.66 x 10¹⁴ N
Two identical guitar strings are prepared such that they have the same length ( 0.66 m ) and are under the same amount of tension. The first string is plucked at one location, primarily exciting the fourth harmonic. The other string is plucked in a different location, primarily exciting the second harmonic. The resulting sounds give rise to a beat frequency of 351 Hz . What is the wave propagation speed on the guitar strings
Answer:
[tex]154.44\ \text{m/s}[/tex]
Explanation:
L = Length of guitar string = 0.66 m
Difference of fourth and first harmonic = 351 Hz
v = Wave propagation speed on the guitar strings
So,
[tex]\dfrac{4v}{2L}-\dfrac{v}{2L}=351\\\Rightarrow \dfrac{3v}{2L}=351\\\Rightarrow v=\dfrac{351\times 2\times 0.66}{3}\\\Rightarrow v=154.44\ \text{m/s}[/tex]
The wave propagation speed on the guitar strings is [tex]154.44\ \text{m/s}[/tex].
What organ in the digestive system ABSORBS NUTRIENTS from broken down food?
Answer:
The small intestine absorbs most of the nutrients in your food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross the intestinal lining into your bloodstream.
Explanation:
At a distance of 40 ft from the pad, a man observes a helicopter taking off from a heliport. If the helicopter lifts off vertically and is rising at a speed of 53 ft/sec when it is at an altitude of 129 ft, how fast is the distance between the helicopter and the man changing at that instant
Answer:
The distance between the helicopter and the man is increasing at a rate of 50.622 feet per second.
Explanation:
First, we create a geometric diagram representing the situation between man (point O), helicopter (point P) and helipad (point H). The distance between man and helicopter is represented by Pythagorean Theorem:
[tex]x^{2}+y^{2} = r^{2}[/tex] (1)
Where:
[tex]x[/tex] - Distance between man and helipad, in feet.
[tex]y[/tex] - Distance between helipad and helicopter, in feet.
[tex]r[/tex] - Distance between man and helicopter, in feet.
By Differential Calculus, we derive an expression for the rate of change of the distance between man and helicopter ([tex]\dot r[/tex]), in feet per second:
[tex]2\cdot x\cdot \dot x + 2\cdot y\cdot \dot y = 2\cdot r\cdot \dot r[/tex]
[tex]\dot r = \frac{x\cdot \dot x + y\cdot \dot y}{r}[/tex]
[tex]\dot r = \frac{x\cdot \dot x + y\cdot \dot y}{\sqrt{x^{2}+y^{2}}}[/tex] (2)
Where:
[tex]\dot x[/tex] - Rate of change of the distance between man and helipad, in feet per second.
[tex]\dot y[/tex] - Rate of change of the distance between helicopter and helipad, in feet per second.
If we know that [tex]x = 40\,ft[/tex], [tex]y = 129\,ft[/tex], [tex]\dot x = 0\,\frac{ft}{s}[/tex] and [tex]\dot y = 53\,\frac{ft}{s}[/tex], then the rate of change of the distance between man and helicopter is:
[tex]\dot r = \frac{x\cdot \dot x + y\cdot \dot y}{\sqrt{x^{2}+y^{2}}}[/tex]
[tex]\dot r = 50.622\,\frac{ft}{s}[/tex]
The distance between the helicopter and the man is increasing at a rate of 50.622 feet per second.
If a runner is running at 100 meters per minute at the exact moment they cross the finish line of a race, it is the
instantaneous speed.
O True
O False
Answer:
Hello! Your answer would be, O False
Explanation:
Hope I helped! Brainiest plz!♥ Have a nice morning! Hope you make a 100%! -Abby
Answer:
False is the correct answer.
Explanation:
plz mark me as brainliest.
When two substances that cannot dissolve each other are mixed, a ________ mixture is formed
Answer: hetero i think i dont know
Explanation:
Answer:
When two substances that cannot dissolve each other are mixed, a mixture is formed.
i hope this helps a little bit.
A
ring
made
up of equal semicircular section
of cast Iron and cast steel with two air gaps
of o-imm and 0.25mm respectively has a cross
soctional area of 400 cm and a mean diameter
of 5m. The ring is uniformly wound with a coil
of 1200 furns. if the relative permeability
of cast iron and cast steel are 2800 and
900 respectively, determine the current
required to produce
a flux of lomwb in
Explanation:
I couldn't have information on this question.
A loudspeaker in a parked car is producing sound whose frequency is 20 510 Hz. A healthy young person with normal hearing is standing nearby on the sidewalk but cannot hear the sound because the frequency is too high. When the car is moving, however, this person can hear the sound. (a) Is the car moving toward or away from the person
Answer:
The car must be moving away from the person.
Explanation:
From Doppler's Effect, we know that when a sound source moves towards a stationary observer, the apparent frequency of that sound increases. While the apparent frequency decreases if the source moves away from the stationary observer.
The audible range of frequencies for a human ear is 20 Hz to 20000 Hz. Therefore, in order for the sound of a loud speaker to be audible for the person, the frequency must decrease below 20000 Hz.
Due to this reason, the car must be moving away from the person.
A microphone is attached to a spring that is suspended from the ceiling, as the drawing indicates. Directly below on the floor is a stationary 440-Hz source of sound. The microphone vibrates up and down in simple harmonic motion with a period of 2.0 s. The difference between the maximum and minimum sound frequencies detected by the microphone is 2.1 Hz. Ignoring any reflections of sound in the room and using 343 m /s for the speed of sound, determine the amplitude of the simple harmonic motion.
Answer:
[tex]0.261\ \text{m}[/tex]
Explanation:
[tex]\Delta f[/tex] = Change in frequency = 2.1 Hz
[tex]f[/tex] = Frequency of source of sound = 440 Hz
[tex]v_m[/tex]= Maximum of the microphone
[tex]v[/tex] = Speed of sound = 343 m/s
[tex]T[/tex] = Time period = 2 s
We have the relation
[tex]\Delta f=2f\dfrac{v_m}{v}\\\Rightarrow v_m=\dfrac{\Delta fv}{2f}\\\Rightarrow v_m=\dfrac{2.1\times 343}{2\times 440}\\\Rightarrow v_m=0.8185\ \text{m/s}[/tex]
Amplitude is given by
[tex]A=\dfrac{v_m T}{2\pi}\\\Rightarrow A=\dfrac{0.8185\times 2}{2\pi}\\\Rightarrow A=0.261\ \text{m}[/tex]
The amplitude of the simple harmonic motion is [tex]0.261\ \text{m}[/tex].
A coil of 10 turns is in the shape of an ellipse having a major axis of 13.0 cm and a minor axis of 6.00 cm. The coil rotates at 73rpm in a region in which the Earth's magnetic field is 55.0 microT. What is the maximum voltage induced in the coil if the axis of rotation of the coil is along its major axis and this axis of rotation is aligned perpendicular to the Earth's magnetic field
Answer:
the maximum voltage induced in the coil is 2.574 × 10⁻⁵ V
Explanation:
Given the data in the question;
Number of turns N = 10
major axis Ma = 13 cm = 0.13 m
a = 0.13/2 = 0.065 m
Minor axis Mi = 6 cm = 0.06 m
b = 0.06/2 = 0.03 m
we know that; 1 RPM = 0.10472 rad/s
rate of rotation R = 73rpm = 7.64 rad/s
Magnetic field = 55 uT
we know that, Area of ellipse = π × a × b
we substitute
A = π × 0.065 m × 0.03 m
A = 0.006126 m²
so
Maximum Voltage = N × Area × Magnetic field × rate of reaction
we substitute
Maximum Voltage = 10 × 0.006126 × ( 55 × 10⁻⁶ ) × 7.64
Maximum Voltage = 2.574 × 10⁻⁵ V
Therefore, the maximum voltage induced in the coil is 2.574 × 10⁻⁵ V
If you were on a spaceship traveling at 0.50c away from a star, what speed
would the starlight pass you?
Explanation:
The speed of light in vacuum is the same by all observers (2nd Principle). You would find that the starlight passes you at c. This is more than a thousand times faster than existing space craft.
According to all observers, the velocity of light in a vacuum will be the same (2nd Principle). You'd discover that the starlight is passing you at c. Compared to current spacecraft, this really is a thousand times faster.
What is Speed?The amount of the shift in approach per unit of time or the size of the displacement over time for an object can be used to describe speed, which would be a scalar quantity in everyday language and kinematics.
The maximum speed that can be maintained when a time period grows closer to zero is the starting speed.
By dividing the object's distance traveled by the duration of the interval, the mean pace of the object for the given period of time is calculated. Speed and velocity are not always the same thing.
To know more about Speed:
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The speed of surface waves in water decreases as the water becomes shallower. Suppose waves travel across the surface of a lake withn a speed of 2m/s and a wavelength of 1.5m. When these waves move into a shallower part of the lake, their speed decreases to 1.6m/s, though their frequency remains the same. Find the wavelength of the wave in the shallower water.
Answer:
The correct solution is "1.2 m".
Explanation:
The given values are:
Wavelength of waves,
λ = 1.5 m
Speed of waves on surface,
V = 2 m/sec
Speed of waves in water,
V₁ = 1.6 m/sec
As we know,
⇒ [tex]V=f\times \lambda[/tex]
or,
⇒ [tex]f=\frac{V}{\lambda}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{2}{1.5}[/tex]
⇒ [tex]=1.33 \ Hz[/tex]
hence,
⇒ [tex]\lambda_1=\frac{V_1}{f}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{1.6}{1.33}[/tex]
⇒ [tex]=1.2 \ m[/tex]
What is the animal behavior where organisms imitate another organism or environment in some way?
Mimicry. This is when oraganisms imitate another oraganism whether it be physical or behavoioral.
What is perihelion and aphelion in short.
I dont know you could start by asking your teacher, parent, and or siblings.
Ps the last part was a joke they never help.
Answer:
I think that perihelion is the point of the Earth's course that is close to the Sun. And i'm sure that aphelion in short is astronomy or otherwise the point in the orbit of a planet.
Explanation:
Hope this helps :)
An object changes velocity from 100m/s
to 76m/s in 6 seconds. If it has a mass of
20kg, what is the net force?
Answer:
1-1=0
Explanation:
ahriqqwertyuioo
A wheel has eight spokes and a radius of 30 cm. It is mounted on a fixed axle and is spinning at 2.5 rev/s. You want to shoot a 24- cm arrow parallel to this axle and through the wheel without hitting any of the spokes Assume that the arrow and the spokes hitting any of the spokes. Assume that the arrow and the spokes are very thin. (a) What minimum speed must the arrow have to pass through (a) What minimum speed must the arrow have to pass through without contact
Answer:
4.8 m/s
Explanation:
Given: angular velocity of wheel ω = 2.5 rev/sec
radius r = 30 cm
length of arrow = 24 cm
For arrow to pass through spinning ring it has to pass between any two spokes of the wheel.
angle between two spokes = π/4
time taken by a spook to reach the position of adjacent spoke t =θ/ω
= π/4/(2.5×2π) = 1/20 sec
for the arrow to pass through the spokes of the wheel it should take time t <1/20 sec to pass through the wheel
a) therefore, minimum speed = (24/100)/(1/20) = 4.8 m/s
A doorknob is a type of wheel and axle. In a doorknob, the door handle acts as the wheel. The handle is connected to a cylinder, called a spindle, which acts as the axle. When the handle turns, the spindle turns in the same direction. The spindle is located inside the handle and pulls the latch back and forth, allowing the door to open.
In the doorknob shown above, when the handle is rotated a distance of 84 millimeters, the spindle is rotated a distance of 14 millimeters. What is the mechanical advantage of this doorknob?
A. 504
B. 6
C. 84
D. 14
two bodies of masses 10 kg and 4 kg are moving in opposite direction with the same velocity of 5 m per second if they Collide and stick together after the impact calculate their velocities
Answer:
dasd
Explanation:
dsdas
A car advertisement states that a certain car can accelerate from rest to
27m/s in 4.9 seconds at a temperature of 75F. What is the acceleration of
the car?
Answer:
Acceleration of the car = 5.51 m/s²
Explanation:
Given:
Initial speed of car = 0 m/s
Final speed of car = 27 m/s
Time taken by car = 4.9 seconds
Find:
Acceleration of the car
Computation:
Using first equation of motion
v = u + at
Where
v = Final velocity
u = Initial velocity
t = Time taken
a = Acceleration
So,
v = u + at
27 = 0 + a(4.9)
a(4.9) = 27
a = 5.51 m/s²
Acceleration of the car = 5.51 m/s²
What is the magnitude and direction of the net force on a ball that has a force of 27N North and 18N North applied to it?
Answer:
Magnitude: = 32.45 Direction: = 33.69Explanation:
The magnitude of the net force acting on an object is equal to the mass of the object multiplied by the acceleration of the object, as shown in this formula. We find its magnitude using the Pythagorean Theorem or the distance formula, and we find its direction using the inverse tangent function. Given a position vector →v=⟨a,b⟩, the magnitude is found by |v|=√a2+b2. The direction is equal to the angle formed with the x-axis, or with the y-axis, depending on the application.
what kind of charge does an object have if it has extra positive charges