Answer: C
Explanation:
USAtestprep
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 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.
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You and your friends are pushing a car with a total of 1080 N of force. You are able to push the car for a distance of 218 m. Calculate the work done on the car.
Answer:
How much power is required to pull a sled if you use 60J of work in 5 seconds? ... Misfortune occurs and Renatta and her friends find themselves getting a workout. They apply a cumulative force of 1080 N to push their car 218 m to the ... Calculate the amount of work done when moving a 567N crate a distance of 20 meters.
Explanation:
Misfortune occurs and Renatta and her friends find themselves getting a ... They apply a cumulative force of 1080 N to push the car 218 m to the nearest fuel ... Write down what they give you. ... Determine the work done by Lamar in deadlifting 300 kg to a height of 0.90 m ... Work = Force x Distance = Joules (force = weight).
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
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 is the flux through the plane taken parnllel to the field?
Answer:
the flux through the plane is zero.
Explanation:
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
Can you please help me ?
Answer:
Distance is 300 and displacement is 100
Explanation:
Distance= 100+100+100=300
Displacement=100
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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.
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 ( •_•)
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 :)
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.
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:
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Which category best describes this group of shapes? rhombuses rectangles parallelograms squares II
they're parallelograms
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:
This is energy of motion
Hint
First two letters Ki
Answer: Kinetic Energy
Explanation:Kinetic energy is the energy of motion. All moving objects have kinetic energy.
Answer:
Kinetic energy
Explanation:
Kinetic energy is energy produced when the object is in motion.
A particle oscillates in simple harmonic motion, with amplitude A and period T. The particle starts from position x = A. What is the magnitude of the particle's displacement a time 3T/2?
A. 3A
B. 6A
C. 2A
D. 0
Answer:
i guess it is D because,
y = A sin(wt)
w = [tex]\frac{2\pi }{T}[/tex] and t = 3T/ 2
now, Y = A sin ( [tex]\frac{2\pi }{T} X \frac{3T}{2}[/tex])
so, Y = 0radian
Explanation:
The magnitude of the particle's displacement a time 3T/2 is zero. The correct option is D.
What is magnitude?Magnitude is simply "distance or quantity" in the context of physics.
A = amplitude of SHM
T = time period of SHM
At t = 0 s, the position of a particle is, x = A
At t = 3T/2, find the magnitude of the particle's displacement
d = magnitude of displacement of particle at time
t = 3T/2
t = ?
t= t1 + t2 = T + T/2
where
t1 = T
t2 = T/2
Now, in time t1 = T, the particle will return to its initial position as the particle completes one full cycle of motion in time T.
Therefore, after time t1 = T, the position of the particle is given by x = A, and the total displacement by the particle is 0.
Now in time
t2=T/2
The particle will go to another extreme position, given by x = -A.
Therefore, the net displacement of particles in time
3/T2
is given by:
d=0+(−A)=−A
d=−A
Therefore, the correct option is D. 0.
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give 3 example of right quantities that have no unit
Answer:
velocity ratio
mechanical advantage
Relative density
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 marble and a basketball are rolling toward you at the same velocity. If the same amount of force is used to stop both objects, what is true about the amount of time needed to stop those objects?
Answer:
The amount of time needed to stop the marble is much less than the amount of time needed to stop the basketball.
Explanation:
To explain this question we can use the equation:
Change in momentum = Force x Time
Where momentum = mass x Velocity
In the case of the basketball, it has a much larger mass than the marble, meaning it has much more momentum than the marble. This means that with the same amount of force, it will need much more time to stop.
Likewise, the marble has less mass than the basketball meaning it will have less momentum. This means that with the same amount of force, it will require less time to stop.
Logically this also makes sense if we think about it in a real life scenario. If we try to stop a marble with our finger, we can stop it much faster then if we try to stop a basketball with our finger because of the difference in mass between the two objects, therefore the marble will require much less time to be stopped than the basketball.
Hope this helped!
Can someone please help me on this?
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
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
A circuit is built based on this circuit diagram.
What is the equivalent resistance of the circuit?
0.61 Ω
Ο 1.6 Ω
7.5Ω
Ο 18 Ω
12V
3.0 Ω.
6.0 Ω
9.Ο Ω.
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[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the concept of resistors,
The equivalent circuit is given as,
1/Rp = 1/3 + 1/6 + 1/9
1/Rp = 6+3+2/18
1/Rp = 11/18
Rp = 18/11 ==> 1.63 ==> 1.6 ohms
hence the equivalent resistance of the circuit is 1.6 ohms
The equivalent resistance of the circuit is 1.6Ω. The correct option is B.
What is Ohm’s law?Ohm’s law state that ” At constant temperature, the current (I) flowing through a conductor is directly proportional to the potential difference(V) across the two endpoints of the given conductor.”
I.e V ∝ I
V=IR
Where V= potential difference across the conductor.
I = current flowing through the conductor.
R= constant pf proportionality i.e resistance which unit is ohm(Ω).
There are two ways we can connect the resistors.
(i) series connection
If a number of resistors are said to be connected in series When the same current (I) flows through them.
Let R1, R2, and R3 be the resistors connected in series.
Then the R equivalent is
Req=R1+R2+R3
(ii) parallel connection
A number of resistors are said to be connected in parallel when the same potential difference(V) exists across each of them.
Let R1, R2, and R3 be the resistors connected in parallel.
Then the R equivalent is
1/Req=1/R1+1/R2+1/R3
In this question,
The three resistance connected in parallel by applying the above formula we get,
1/Req=1/R1+1/R2+1/R3
1/Req = 1/3 + 1/6 + 1/9 ................. (∵R1=3Ω,R2=6Ω AND R3=9Ω)
1/Req =11/18
Req=18/11
Req=1.6363Ω
Req≈1.6Ω
Therefore, The equivalent resistance of the circuit is 1.6Ω.
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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:
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Answer:
False is the correct answer.
Explanation:
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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].
Which electromagnetic wave has the shortest wavelength?
Which electromagnetic wave would have a wavelength approximately the size of the tip of a pencil?
Which electromagnetic wave has the longest wavelength?
Answer:
shortest - gamma Ray's
size of a pencil tip : most likely microwaves
longest - radio waves
Gamma rays have the shortest wavelength whereas Radio waves have the longest wavelength. The wave whose wavelength is about the size of the tip of a pencil is infrared ray.
What is an Electromagnetic spectrum?The whole electromagnetic waves are divided into several classes based on their frequencies or energies as follows, in the order of increasing frequency:
Radio waves
Microwaves
Infrared
Visible
Ultraviolet
X-rays
Gamma rays
The Gamma rays are the shortest wavelength group with frequencies greater than 3 × 10²⁰ Hz.
The Radio waves are the longest wavelength group. Their frequency is lower than 3 × 10⁷ Hz.
The tip of a pencil is about 0.5mm in width.
Calculate the frequency of the wave whose wavelength is about the size of the tip of a pencil i.e. λ = 0.5 mm,
ν = 3×10⁸/(0.5×10⁻³) = 6×10¹¹ Hz.
The infrared rays have frequencies in the range of 3×10¹¹ Hz to 3×10¹³ Hz. So, the wave is infrared.
Infrared waves have a wavelength about the tip of a pencil.
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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 ball bounces changing velocity from vi=15m/s[D] to vf=15m/s[U] in t=0.01s. The balls acceleration is *
A) 0
B) 30m/s/s
C) 3000m/s/s
D) 0.3m/s/s
Answer:
Option (A) is correct
Explanation:
a= (vf-vi)/ t
put the values
hence,
a= ( 15-15)/0.01
a=0
Average running speed is 8km/h. Convert this to m/s :
a)8m/s
b)2.2m/s
c)28.8m/s
d)8km/h
Answer:
Im not sure if you mean miles per hour or meters per hour but if it is miles it is 4.97 miles per hour and if it is meters then it is 8000 meters per hour
Explanation:
Sorry if I'm wrong