Answer:
Work is the energy needed to apply a force to move an object a particular distance, where force is parallel to the displacement. Power is the rate at which that work is done.
Answer: Work is the energy needed to apply a force to move an object a particular distance, where force is parallel to the displacement. Power is the rate at which that work is done.
Explanation:
Which exerts more force, the Earth pulling on the moon or the moon pulling on the Earth? Explain.
Answer: the earth
Explanation: Earth exerts a gravitational pull on the moon 80 times stronger than the moon's pull on the Earth. Over a very long time, the moon's rotations created fiction with the Earth's tugging back, until the moon's orbit and rotational locked with Earth.
and that's why the earth pulls the moon
Which of the following is the closest to the scientific fact
A. A hypothesis
B. A theory
C. An opinion
D. A prediction
A theory is the closest to a scientific fact (Option B).
A scientific theory is a well-sustained scientific idea that has been verified using the scientific method.A scientific theory can be refuted by the emergence of new lines of evidence against some aspect of this scientific statement.A hypothesis is a given explanation about a question that emerged by observing the natural world.In conclusion, a theory is the closest to a scientific fact (Option B).
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The boys are finally old enough to compete in the box car derby race at the local fair. They have been working on their cars since the conclusion of the race last year. One boy's car raced down the track and placed 2nd in his race. However, the other boy's car started well but half-way through the race a wheel came off and his car came to a complete stop. The boy was very disappointed and the other boy felt horrible for his friend. Which of the following graphs best represents the motion of boy's car that stopped?
A boy whirls a ball on a string in a horizontal circle of radius 1 m. How many revolutions per minute must the ball make if its acceleration towards the center of the circle is to have the same magnitude as the acceleration due to gravity
Answer:
Nearest, the revolutions per minute will be 29.
Explanation:
Given that,
Radius of circle = 1 m
Acceleration a =g
We know that,
Angular frequency is defined as,
[tex]\omega=2\pi n[/tex]
Where, n = number of revolutions in one second
We need to calculate the revolutions in one second
Using formula of centripetal acceleration
[tex]a=\omega^2r[/tex]
Put the value of a and ω
[tex]g=(2\pi n)^2r[/tex]
[tex]n=\sqrt{\dfrac{g}{r}}\times\dfrac{1}{2\pi}[/tex]
Put the value into the formula
[tex]n=\sqrt{\dfrac{9.8}{1}}\times\dfrac{1}{2\pi}[/tex]
[tex]n=0.49[/tex]
We need to calculate the revolutions per minute
Using value for the revolutions per minute
[tex]n=0.49\times60[/tex]
[tex]n=29.4[/tex]
Hence, Nearest, the revolutions per minute will be 29.
A crane uses a single cable to lower a steel girder into place. The girder moves with constant speed. The cable tension does work WT and gravity does work WG. Which statement is true
Explanation:
Work done by a force is given by :
[tex]W=Fd\cos\theta[/tex]
Where
F is force, d is displacement and [tex]\theta[/tex] is the angle between F and d.
In this problem, a crane is moving in downward direction, the force gravity is in downward direction and the tension is in upward direction.
We know that if force and displacement is in same direction, work is positive while if force and displacement is in oposite direction, work is negative.
I would mean that, [tex]W_g[/tex] is positive, because gravity is parallel to the displacement and [tex]W_t[/tex] is negative, because the tension is opposite to the displacement.
What is the speaker’s power output if the sound intensity level is 102 dBdB at a distance of 25 mm ? Express your answer to two significant figures and include the appropriate units.
Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,
[tex]\beta (dB)= 10 \ log_{10 } (\dfrac{I}{I_o})[/tex]
where;
the threshold of hearing [tex]I_o = 10^{-12} (W/m^2)[/tex]
[tex]\dfrac{102 }{10}= log_{10}( \dfrac{I}{10^{-12}})[/tex]
[tex]10^{10.2} = \dfrac{I}{10^{-12}}[/tex]
[tex]I = 10^{10.2} \times 10^{-12}[/tex]
I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W
If the power supply is to be made safe by increasing its internal resistance, what should the internal resistance be for the maximum current in the above situation to be Imax
The complete question is;
A person with body resistance between his hands of 10 kΩ accidentally grasps the terminals of a 16-kV power supply. What is the power dissipated in his body?
A) If the internal resistance of the power supply is 1600 Ω , what is the current through the person's body?
B) What is the power dissipated in his body?
C) If the power supply is to be made safe by increasing its internal resistance, what should the internal resistance be for the maximum current in the above situation to be I_max = 1.00mA or less?
Answer:
A) I = 1.379 A
B) P = 19016.41 W
C) r = 15990000 Ω
Explanation:
A) We are given;
Internal resistance of the power supply; r = 1600 Ω
Body resistance between hands; R = 10kΩ = 10000 Ω
Power supply voltage; E =16 kV = 16000 V
Formula for the current through the person's body with internal resistance is given by;
I = E/(R + r)
Thus;
I = 16000/(10000 + 1600)
I = 1.379 A
B) Formula for power dissipated is;
P = I²R
P = 1.379² × 10000
P = 19016.41 W
C) Now, we are told that the maximum current should be I_max = 1.00mA or less. So, I_max = 0.001 A
Thus, from I = E/(R + r) and making r the subject, we have;
r = (E/I) - R
r = (16000/0.001) - 10000
r = 15990000 Ω
Please help me with this!
hope this helps good luck
A vector of components (−23, −22) is multiplied by the scalar value of −6. What is the magnitude and direction of the resultant vector?
Answer:
(1,)
Explanation:
Answer:
magnitude: 21.6; direction: 33.7°
Explanation:
How do I proton and and electron compared
1. What quantity of heat is required to raise?
the temperature of 450 grams of water
from 35°C to 85°C?
capacity of water is 4.18 J/g °C.
Answer: Calculate the energy required in joules to raise the temperature of 450 grams of water from 15°C to 85°C? (The specific heat capacity of water is 4.18 J/g/°C)
Explanation:
The quantity of heat is required to raise the temperature of of water is 94050 joule.
What is law of conservation of energy?Energy cannot be created or destroyed, according to the law of conservation of energy. However, it is capable of change from one form to another. An isolated system's total energy is constant regardless of the types of energy present.
The law of energy conservation is adhered to by all energy forms. The law of conservation of energy essentially says that the total energy of the system is conserved in a closed system, also known as an isolated system.
Mass of water: m = 450 grams
Initial temperature of water = 35° C
Final temperature of water = 85° C
Capacity of water is 4.18 J/g °C.
Hence, the quantity of heat is required to raise = mass × Capacity × raise in temperature
= 450 × 4.18 × (85 - 35) joule
= 94050 joule.
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distance is constant and time increseas
Will Speed increase or decrease?
Answer:
The speed will be decrease
please help asap
You jog for 55 minutes and reach a park that is 4.8 km away. What was your speed?
Answer: 59.8 or 299/5- 55 x 4.8=264
Explanation:
Or if you wish to multiply it then the answer is above with the addition version.
Hope this helped :)
Which best explains a difference between Einstein’s general theory of relativity and his special theory of relativity?
His general theory includes uniform and accelerated motion, but his special theory applies only to uniform motion.
His general theory includes uniform and accelerated motion, but his special theory applies only to accelerated motion.
His general theory applies only to accelerated motion, but his special theory includes uniform and accelerated motion.
His general theory applies only to uniform motion, but his special theory includes uniform and accelerated motion.
Answer:
His general theory includes uniform and accelerated motion, but his special theory applies only to uniform motion.
Explanation:
According to Einstein's 1915 general theory of relativity, the force of gravity arises from the curvature of space and time.
According to theory of special relativity:
1. The laws of physics are the same for all non-accelerating observers
2. The speed of light in a vacuum was independent of the motion of all observers.
His general theory includes uniform and accelerated motion, but his special theory applies only to uniform motion.
Answer:
for those who dont like to read
the answer is A.
hope i helped
Explanation:
Which factor affects the amount of runoff that occurs in an area?
land use
the water table
the saturation zone
amount of nutrients in soil
Answer:
A. land use
Explanation:
Answer:
a
Explanation:
In which region does the ocean get the most sunlight throughout the year?
A. Near the equator
B. Near the poles
C. Northern mid-latitudes
D. Southern mid-latitudes
Answer: a
Explanation:
The ocean near the equator gets the most sunlight throughout the year, therefore the correct option is A.
What is the equator?The Equator is an imaginary line passing through the middle of a globe. It is equidistant from the North Pole and the South Pole, Its is a horizontal line residing at 0 degrees latitude.
Because of the revolving position of the earth in the solar system, The ocean near the equator gets the most sunlight throughout the year, therefore the correct option is A.
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The mass of a dropped object impacts its final velocity but not its acceleration.
Explanation:
because of the acceleration due to gravity is constant which is 9.8
Answer:
TRUE
Explanation:
CUZ , IT DOSEN'T AFFECT
Mass does not affect the speed of falling objects, assuming there is only gravity acting on it. Both bullets will strike the ground at the same time.
At an amusement park, a swimmer uses a water slide to enter the main pool. You may want to review (Pages 234 - 241) . Part A If the swimmer starts at rest, slides without friction, and descends through a vertical height of 2.81 m , what is her speed at the bottom of the slide
Answer:
Her speed at the bottom of the slide is 7.42 m/s
Explanation:
From the question,
The swimmer starts at rest, that is, her initial speed, u is 0 m/s.
Since she slides without friction and descends through a vertical height, then it is a free fall motion (due to gravity).
Also, from the question,
She descends through a vertical height of 2.81 m.
To determine her speed at the bottom of the slide, that is her final speed,
From one of the equations of motion for freely falling bodies
v² = u² + 2gh
Where v is the final speed
u is the initial speed
g is acceleration due to gravity (g = 9.8 m/s²)
and h is height
From the question,
u = 0 m/s
h = 2.81 m
Putting the values into the equation
v² = u² + 2gh
v² = 0² + 2×9.8×2.81
v² = 55.076
v =√55.076
v = 7.42 m/s
Hence, her speed at the bottom of the slide is 7.42 m/s.
On a hot day, you sit on the edge of a pool and dip your feet into the water, causing changes to occur that are related to the physical and thermal properties of your feet and of the water. Select the statements that accurately describe what is happening, in terms of the heat and temperature of the objects and substances. There may be more than one accurate statement.
The true statements are;
Heat from your feet raises the temperature of the water.
Your feet transfer heat into the surrounding water, reducing the temperature of your feet. B and C
What are thermal changes?The term thermal changes has t do with the changes in the heat properties of the substance. We know that when you put your leg in water there is a thermal exchange between the water and your leg.
Owing to the fact that heat is transferred from your leg to the water, your leg will feel cool while the temperature of the water will increase slightly.
Having said all these, the true statements are;
Heat from your feet raises the temperature of the water.
Your feet transfer heat into the surrounding water, reducing the temperature of your feet.
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Missing parts;
On a hot day, you sit on the edge of a pool and dip your feet into the water, causing changes to occur that are
related to the physical and thermal properties of your feet and of the water. Select the statements that
accurately describe what is happening, in terms of the heat and temperature of the objects and substances.
There may be more than one accurate statement.
A. Cold from the water reduces the temperature of your feet.
B. Heat from your feet raises the temperature of the water.
C. Your feet transfer heat into the surrounding water, reducing the temperature of your feet.
D. Cold from the water moves into your warm feet.
A student uses a microwave oven to heat a meal. The wavelength of the radiation is 8.97 cm. What is the energy of one photon of this microwave radiation? Multiply the answer you get by 1025 to be able to input a number more easily into canvas. Enter to 2 decimal places.
Answer:
The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
Explanation:
The energy (E) of a photon is:
[tex] E = h\frac{c}{\lambda} [/tex]
Where:
h: is the Planck's constant = 6.62x10⁻³⁴ J.s
λ: is the wavelength of the radiation = 8.97 cm
c: is the speed of light = 3.00x10⁸ m/s
[tex] E = h\frac{c}{\lambda} = 6.62 \cdot 10^{-34} J.s\frac{3.00\cdot 10^{8} m/s}{8.97 \cdot 10^{-2} m} = 2.21 \cdot 10^{-24} J [/tex]
Hence, the energy of one photon is 2.21x10⁻²⁴ J.
Now, if we multiply the answer by 10²⁵ we have:
[tex] E = 2.21 \cdot 10^{-24} J \cdot 10^{25} = 22.10 J [/tex]
I hope it helps you!
The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
Calculation of energy:We know that
[tex]E = h\frac{c}{\lambda}[/tex]
Here
h be the Planck's constant = 6.62x10⁻³⁴ J.s
λ be the wavelength of the radiation = 8.97 cm
c be the speed of light = 3.00x10⁸ m/s
Now
Here we need to multiply the answer 10^25 so that the correct answer could come.
[tex]E = 6.62.10^{-34} \frac{3.00.10^{8}}{8.97.10^{-2}}[/tex]
= 2.21x10⁻²⁴ J.
= 22.10 J.
Hence, the energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
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Engineers are using computer models to study train collisions to design safer
train cars. They start by modeling an elastic collision between two train cars
traveling toward each other. Car 1 is traveling north at 20 m/s and has a mass
of 12,745 kg. Car 2 is traveling south at 15 m/s and has a mass of 4,125 kg.
After the collision, car 1 has a final velocity of 3 m/s north. What is the final
velocity of car 2?
A. 56 m/s north
B. 56 m/s south
C. 38 m/s south
D. 38 m/s north
Answer:
did you get the answer???
Answer: 38 m/s north
Explanation:
Victor has 100 trading cards, each with a distinct power level between 101 and 200 inclusive. Whenever he heads out, he always randomly selects 21 cards to bring with him just in case he meets a fellow collector. Prove that no matter which 21 cards he brings, Victor will always be able to select 4 of those cards that exhibit the following property:
Let the average power level of all 4 cards bep. The cards can be split into two pairs, each of which also has an average power level of p.
Answer:
Victor will always be able to select 4 of those cards with the following property
Explanation:
Number of trading cards = 100
victor selects 21 cards
let the 4 cards be labelled : A,B,C and D
The average power level of : A,B,C,D = ( A + B + C + D )/ 4 = P
let the two pairs be : ( A + B ) and ( C + D )
note: average power of each pair = P and this shows that
( A + B ) = ( C + D ) for Victor to select 4 cards out of the 21 cards that exhibit the same property
we have to check out the possible choices of two cards out of 21 cards yield distinct sums.
= C(21,2)=(21x20)/2 = 210.
from the question the number of distinct sums that can be created using 101 through 200 is < 210 .
hence it is impossible to get 210 distinct sums therefore Victor will always be able to select 4 of those cards
7N
6
→ 2N
Net Force:
Determine the net force acting on the object.
Answer:
When a force is applied to the body, not only is the applied force acting, there are many other forces like gravitational force Fg, frictional force Ff and the normal force that balances the other force. Therefore, the net force formula is given by, FNet = Fa + Fg + Ff + FN.
Explanation:
One airplane is approaching an airport from the north at 181 kn/hr. A second airplane approaches from the east at 278 km/hr. Find the rate at which the distance between the planes changes when the southbound plane is 30 km away from the airport and the westbound plane is 15 km from airport.
Answer:
The value is [tex] \frac{dR}{dt} = -286.2 \ km/hr [/tex]
Explanation:
From the question we are told that
The speed of the airplane from the north is [tex]\frac{dN}{dt} = -181 \ km /hr[/tex]
The negative sign is because the direction is towards the south
The speed of the airplane from the east is [tex]\frac{dE}{dt} = -278 \ km/hr[/tex]
The negative sign is because the direction is towards the west
The distance of the southbound plane from the airport is [tex]N = 30 \ km[/tex]
The distance of the westbound plane is [tex]E = 15 \ km[/tex]
Generally the distance between the plane is mathematically represented using Pythagoras theorem as
[tex]R^2 = N^2 + E^2[/tex]
Next differentiate implicitly this equation to obtain the rate at which the distance between the planes changes
So
[tex]2R\frac{dR}{dt} = 2N \frac{dN}{dt} + 2E\frac{dE}{dt}[/tex]
Here
[tex]R = \sqrt{N^2 + E^2}[/tex]
=> [tex]R = \sqrt{30^2 + 15^2}[/tex]
=> [tex]R = \sqrt{30^2 + 15^2}[/tex]
=> [tex]R =33.54 \ m [/tex]
[tex]2(33.54) * \frac{dR}{dt} = 2( 30)*(-181) + 2*15*(-278)[/tex]
=> [tex] 67.08 * \frac{dR}{dt} = -19200[/tex]
=> [tex] \frac{dR}{dt} = -286.2 \ km/hr [/tex]
The rate of change of the distance between the planes is 286.23 km/hr.
The given parameters;
speed of the airplane from North, dn/dt = 181 Km/hspeed of the airplane from the East, de/dt = 278 km/hnorth distance, n = 30 kmeast distance, e= 15 kmThe distance between the two planes is calculated by applying Pythagoras theorem as shown below;
[tex]d^2 = n^2 + e^2\\\\d = \sqrt{n^2 + e^2} \\\\d = \sqrt{30^2 + 15^2} \\\\d = 33.54 \ km[/tex]
The rate of change of the distance between the planes is calculated as follows;
[tex]d^2 = e^2 + n^2\\\\2\frac{dd}{dt} = 2e\frac{de}{dt} + 2n\frac{dn}{dt} \\\\d\frac{dd}{dt} = e\frac{de}{dt} + n\frac{dn}{dt}\\\\(33.54) \frac{dd}{dt} = (15)(278) \ + (30)(181)\\\\(33.54) \frac{dd}{dt} = 9600\\\\\frac{dd}{dt} = \frac{9600}{33.54} \\\\\frac{dd}{dt} = 286.23 \ km/hr[/tex]
Thus, the rate of change of the distance between the planes is 286.23 km/hr.
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How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns
Complete Question
How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns.
The output from the secondary coil is 12 V
Answer:
The value is [tex]N_s = 21 \ turns [/tex]
Explanation:
From the equation we are told that
The input voltage is [tex]V_{in} = 120 \ V[/tex]
The number of turns of the primary coil is [tex]N_p = 210 \ turn[/tex]
The output from the secondary is [tex]V_o = 12V[/tex]
From the transformer equation
[tex]\frac{N_p}{V_{in}} =\frac{N_s}{V_o}[/tex]
Here [tex]N_s[/tex] is the number of turns in the secondary coil
=> [tex]N_s = \frac{N_p}{V_{in}} * V_s[/tex]
=>[tex]N_s = \frac{210}{120} * 12[/tex]
=>[tex]N_s = 21 \ turns [/tex]
A plastic block of dimensions 2.00 cm x 3.00 cm x 4.00 cm has a mass of 30.0 g. What is its density?
Answer:
1.25 g/cm^3
Explanation:
mass-30.0g
volume- 4cm×2cm×3cm=24cm^3
density?
*to find density
Density=Mass/Volume
=30÷24
=1.25g/cm^3
Six seconds after starting from rest, a car is moving at 15 m/s. What is the car's
average acceleration?
6 m/s2
0-5 m/s?
5 m/s2
2.5 m/s?
-2.5 m/s?
Answer:
2.5 m/s²
Explanation:
a = ∆v/∆t = (15 m/s)/(6 s) = (15/6) m/s² = 2.5 m/s²
For an answer to be complete the units need to be specified.why?
If Mary runs 5 miles in 50 minutes, what is her speed with the correct
label?
give three factors which are responsible for the vanishing forest
Answer:
1. Huge wildfires
2. Deforestation
3. Reduced amount of aforestation, etc