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) Neil A. Armstrong was the first person to walk on the moon. The distance between the earth and the moon is 3.85 x 108 m. Find the time it took for his voice to reach earth via radio waves. (b) Someday a person will walk on Mars, which is 5.6 x 1010 m from earth at the point of closest approach. Determine the minimum time that will be required for that person's voice to reach earth.
Answer:
a). 1.28333 seconds
b). 186.66 seconds
Explanation:
a). Given :
Distance between the earth and the moon, d = [tex]$3.85 \times 10^8$[/tex] m
Speed of the radio waves, c = [tex]$3 \times 10^8$[/tex] m/s
Therefore the time required for the voice of Neil Armstrong to reach the earth via radio waves is given by :
[tex]$t=\frac{d}{c}$[/tex]
[tex]$=\frac{3.85 \times 10^8}{3 \times 10^8}$[/tex]
= 1.28333 seconds
b). Distance between Mars and the earth, d = [tex]$5.6 \times 10^{10}$[/tex] m
Speed of the radio waves, c = [tex]$3 \times 10^8$[/tex] m/s
So, the time required for his voice to reach earth is :
[tex]$t=\frac{d}{c}$[/tex]
[tex]$=\frac{5.6 \times 10^{10}}{3 \times 10^8}$[/tex]
= 186.66 seconds
19. What is shape of BF3
Explanation:
The geometry of the BF 3 molecule is called trigonal planar (see Figure 5). The fluorine atoms are positioned at the vertices of an equilateral triangle. The F-B-F angle is 120° and all four atoms lie in the same plane.
11.Electricity is made at a power plant by huge
(C). Coil
(D). Wire
(A). Motor
(B). Generator
government as an academic field of study
Answer: True
Explanation:
Government as an academic field of study refers to the study of political institutions, processes and theories taught in schools, colleges and higher institution of learning. It is called Political Science in higher institution.
A heating coil operates on 220 V if it draws 15.0 A. Find it's resistance
Answer:
R ≈ 15 ohms
Explanation:
Using ohm's law equation,
I = V/R, to solve for the resistance of the heating coil.
R = V/I
Known:
V = 220 v = 220 kgm^2s^-3A^-1
I = 15 A
Unknown:
R =?
Solution:
R = (220 kgm^2s^-3A^-1)/ 15.0 A
R = 14.6 kgm^2s^-3A^-2
R ≈ 15 kgm^2s^-3A^-2
R ≈ 15 ohms
A ray diagram is shown. A tree acts as the object further than 2 F away from a biconvex lens. The distance between 2 F and the object is labeled W. The distance between F and 2 F is labeled X. There I a light ray parallel to the principal axis is bent through F on the image side of the lens. There is a ray straight through the center of the lens. The rays intersect a point below the principle axis between F and 2 F on the image side of the lens and is closer to the principal axis than the object is tall. The intersect point is labeled Z and the distance between F and 2 F on the image side of the lens is labeled Y. Which letter represents the location of the image produced by the lens? W X Y Z
Answer:
Z
Explanation:
correct on edge
Answer: Z
good luck!
How long will it take you to drive, at 80km/h a distance of 275km?
Answer:
3.44 s
Explanation:
speed=distance/time
=>t = s/v
=> t = 275/80
= 3.437.. s
has been proposed to use an array of infrared telescopes spread over thousands of kilometers of spaceto observe planets orbiting other stars. Consider such an array with an effective diameter of 6000 km, whichobserves infrared radiation at a wavelength of 10m. If it is used to observe a planet orbiting the star 70Virginis, which is 59 light years from our solar system, what is the size of the smallest details that the arraymight resolve on the planet
Answer:
[tex]\triangle x=1.135 *10^9km[/tex]
Explanation:
From the question we are told that:
Diameter of array[tex]d=6000km \approx 6000*10^3[/tex]
Infrared wavelength [tex]\lambda =10m[/tex]
Distance of planet [tex]d=59 light\ years \approx 55.82*10^{16}m[/tex]
Generally the equation for Diffraction is mathematically given by
[tex]sin\theta =1.22\frac{\lambda}{D}[/tex]
Given that
[tex]sin\theta=\frac{\triangle x}{R}[/tex]
Therefore
[tex]\frac{\triangle x}{R}=1.22\frac{\lambda}{D}[/tex]
[tex]\triangle x=1.22\frac{R \lambda}{D}[/tex]
[tex]\triangle x=1.22\frac{10 *55.82*10^{16}}{6000*10^3}[/tex]
[tex]\triangle x=1.135 *!0^1^2m[/tex]
[tex]\triangle x=1.135 *10^9km[/tex]
what term is used to describe the block of organs (heart, lungs, liver, kidneys and spleen) that are removed during the autopsy?
The term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
The organs that are removed during autopsy include:
Thoracic organs;Cervical organs, and Abdominal organsThe thoracic cavity contains organs and tissues that function in the respirator, cardiovascular, nervous and digestive system.
These thoracic organs include the following;
heart, lungs, liver, kidneys and spleen.Thus, we can conclude that the term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
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A 700-gram grinding wheel 22.0 cm in diameter is in the shape of a uniform solid disk. (We can ignore the small hole at the center.) When it is in use, it turns at a constant 215 rpm about an axle perpendicular to its face through its center. When the power switch is turned off, you observe that the wheel stops in 50.0 s with constant angular acceleration due to friction at the axle.
What torque does friction exert while this wheel is slowing down?
Solution :
Given :
Mass of grinding wheel, m = 700 g
= 0.7 kg
Diameter of the grinding wheel, d = 22 cm
= 0.22 m
Radius of the grinding wheel, r = 0.11 m
Initial angular velocity of grinding wheel, [tex]$\omega_0$[/tex] = 215 rpm
[tex]$=215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}$[/tex]
where, [tex]$\pi = \frac{22}{7}$[/tex]
Time taken to stop, t = 50 s
Final angular velocity is [tex]$\omega$[/tex] = 0
Angular acceleration of the grinding wheel is given by :
[tex]$\alpha = \frac{\omega-\omega_0}{t}$[/tex]
[tex]$=\frac{0-215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}}{50 \ s}$[/tex]
[tex]$=-0.45 \ rad/s^2$[/tex]
Magnitude of the angular acceleration of grinding wheel [tex]$\alpha$[/tex] [tex]$=-0.45 \ rad/s^2$[/tex]
Moment of inertia of the grinding wheel (solid disk),
[tex]$I=\frac{1}{2}mR^2$[/tex]
[tex]$=\frac{1}{2} \times 0.7 \times 0.11^2$[/tex]
[tex]$=4.235 \times 10^{-3} \ kgm^2$[/tex]
Torque exerted by friction while the wheel is slowing down is
[tex]$\tau = I \alpha$[/tex]
[tex]$=4.235 \times 10^{-3} \times 0.45$[/tex]
[tex]$=1.90 \times 10^{-3} \ Nm$[/tex]
The diagram shows a charge moving into an electric field. The charge will most likely leave the electric field near which letter? OW OX OY OZ
you haven't attached the diagram, but i assume that this diagram is what you were talking about
Answer:
near Y
Explanation:
the electric field lines goes from a positive charge to a negative charge. This means that a positive charge would move in the same direction of the field lines, while a negative charge would move in the opposite direction of the field lines. the field lines are created from +vely charged plate to -vely charged plate so the negative charged particles moves towards the lower plate which is positively charged, and opposite to the direction of field lines.
The charge will most likely leave the electric field near Y letter. Hence option C is correct.
What is electric charge ?Electric charge is the physical property of matter that experiences force when it is placed in electric field. F = qE where q is amount of charge, E = electric field and F = is force experienced by the charge. there are two types of charges, positive charge and negative charge which are generally carried by proton and electron resp. like charges repel each other and unlike charges attract each other. the flow charges is called as current. Elementary charge is amount of charge a electron is having, whose value is 1.602 x 10⁻¹⁹ C
The charge on the electron is negative, and the force is directed in the opposite direction as the electric field. When an electron is projected perpendicular to a uniform electric field, it experiences an electric force in the opposite direction of the field.
the trajectory of the charged particle in the electric filed is parabolic and in magnetic field it is circular. when this electron moves perpendicular to the electric field, electron experience force in opposite direction to the electric field and due to parabolic nature, it will leave at Y.
Hence option C is correct.
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Think of a hydropower dam . How is electrical energy produced from potential and kinetic energy ?
hydroelectric dam converts the potential energy stored in a water reservoir behind a dam to mechanical energy—mechanical energy is also known as kinetic energy. ... The generator converts the turbine's mechanical energy into electricity.
Hope this helps!
Answer:
Potential energy and kinetic energy are constituents of mechanical energy.
When a turbine is switched on, it rotates with mechanical energy.
Since a motor runs the turbine, it converts this mechanical energy to electrical energy.
What is the term that describes waves that require a medium through which to travel?
Answer:
Mechanical waves are waves that require a medium. This means that they have to have some sort of matter to travel through. These waves travel when molecules in the medium collide with each other passing on energy. One example of a mechanical wave is sound.
A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth.
What process explains this change?
pulling
weathering
depositing
eroding
Answer:
Eroding
Explanation:
A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth. The process explains this change is Eroding. Hence, Option D is the correct answer.
What is Erosion?Erosion is a process of eroding some solids by wind, water and other natural agent while weathering is breaking down of rocks, soil and minerals.
The different types of Erosion includes,
Gully erosionsheet erosionRill erosionsheet erosionThese factors that will contribute to the rate of water erosion includes the climatic factor (rainfall amount, intensity and frequency).
TopographySoil coverSoil propertiesMass wasting erosion if it is a type of erosion but not by water. It is a type of erosion that is generated mainly by the effect of gravity. It is also called mass movement, in which the material detaches from an inclined surface and falls as a result of gravity.
Here, A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth. The process explains this change is Eroding. Hence, Option D is the correct answer.
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what is friction and the types withe examples.
Explanation:
The answer is In the picture. Thanks.
How many times a minute does a boat bob up and down on ocean waves that have a wavelength of 35.6 m and a propagation speed of 4.68 m/s? (the answer may not be a whole number)
Answer:
It will bob 7.887640449 times a minute
Explanation:
I hope this is correct!!
what is the relationship between Force, area and mass
Answer:
F=ma
Explanation:
Force is equal to mass multiplied by area
Force= mass × area
In turn the formula can be twisted so
Force/mass= area
Force/area= mass
Answer:
It states that the rate of change of velocity of an object is directly proportional to the force applied and takes place in the direction of the force. It is summarized by the equation: Force (N) = mass (kg) × acceleration (m/s²). Thus, an object of constant mass accelerates in proportion to the force applied.
physics grade9 teacher guide
Answer:
huh
Explanation:
A body starts from rest and travels ‘s’ m in 2nd second, than acceleration is.
1) 2s m / s2 2) 3 s m / s2 3) 23 s m / s2 4) 32 s m / s2
Answer:
3m
Explanation:
A block and tackle of 6 pulleys is used to raise a load of 300 newton steadily through a height of 30 meters. If the work done against friction is 2000j calculate the work done by effort?
Answer:
W = F * S = 300 N * 30 m = 9000 Joules
This is the work out of the system regardless of how the pulleys are arranged
Conservation of energy tells that
Work Out = Work In - Work done by friction
So Work In = 9000 J + 2000 J = 11000 J The work input to the system
Identical satellites X and Y of mass m are in circular orbits around a planet of mass M. The radius of the planet is R. Satellite X has an orbital radius of 3R, and satellite Y has an orbital radius of 4R. The kinetic energy of satellite X is Kx . Satellite X is moved to the same orbit as satellite Y by a force doing work on the satellite. In terms of Kx , the work done on satellite X by the force is
Answer:
The work down on satellite X by the force in terms of Kx is [tex]\dfrac{-K_x}{4}[/tex].
Explanation:
The work done is given as in terms of
[tex]W=\Delta TE[/tex]
Where ΔTE is the change in total energy.
This is given as
[tex]W=\Delta TE\\W=TE_y-TE_x\\W=\dfrac{-GMm}{2(4R)}-\dfrac{-GMm}{2(3R)}\\W=\dfrac{-GMm}{8R}+\dfrac{GMm}{6R}\\W=\dfrac{-6GMm+8GMm}{48R}\\W=\dfrac{2GMm}{48R}\\W=\dfrac{GMm}{24R}[/tex]
Rearranging it in terms of K_x gives
[tex]W=\dfrac{GMm}{24R}\\W=\dfrac{GMm}{-4\times -6R}\\W=\dfrac{1}{-4}\dfrac{-GMm}{6R}\\W=\dfrac{1}{-4}\dfrac{-GMm}{2(3R)}\\W=\dfrac{1}{-4}K_x\\W=\dfrac{-K_x}{4}[/tex]
On Apollo Moon missions, the lunar module would blast off from the Moon's surface and dock with the command module in lunar orbit. After docking, the lunar module would be jettisoned and allowed to crash back onto the lunar surface. Seismometers placed on the Moon's surface by the astronauts would then pick up the resulting seismic waves.
Find the impact speed of the lunar module, given that it is jettisoned from an orbit 110 km above the lunar surface moving with a speed of 1600 m/s .
My Approach:
Ei = Ef
1/2*m*vi2 - (G*m*ME)/(radius of moon + orbital distance) = 1/2*m*vf2 - (G*m*ME)/r
=> (0.5 * m * 16002) - (6.67 * 10-11 * 7.35*1022 * m/(1737.4*103 +180*103) = (0.5*m*v^2) - (6.67*10-11 * 7.35*1022 * m/(1737.4*103 )
Answer:
Following are the solution to the given question:
Explanation:
For crashing speed, we can use energy conservation:
kinetic energy [tex]= \frac{1}{2}\times m \times v^2[/tex]
potential energy [tex]= -\frac{GMm}{r}[/tex]
moon mass[tex]= 7.36\times 10^{22} \ kg[/tex]
Radius[tex]= 1738\ km[/tex]
[tex]\to (K + U) \ orbit = (K + U)\ crash\\\\\to \frac{1}{2}\times m \times v_o^2 - \frac{GMm}{(1738000 + 110000)} \\\\ \to \frac{1}{2}\times m \times vc^2 - \frac{GMm}{1738000}[/tex]
Calculating the mass drop for the leave:
[tex]\to \frac{vo^2}{2} - \frac{GM}{1848000}\\\\ \to \frac{vc^2}{2} - \frac{GM}{1738000}[/tex]
Solve the value for
[tex]vc = \sqrt{(vo^2 +2\times GM \times(\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = \sqrt{(1600^2 +2\times 6.67\times 10^{-11} \times 7.36 \times 10^{22}\times (\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = 1701 \ \frac{m}{s}\\\\[/tex]
The approach is correct but misrepresented in replacing 180 km instead of 110 km.
Suppose a 65 kg person stands at the edge of a 6.5 m diameter merry-go-round turntable that is mounted on frictionless bearings and has a moment of inertia of 1850 kgm2. The turntable is at rest initially, but when the person begins running at a speed of 3.8 m/s (with respect to the turntable) around its edge, the turntable begins to rotate in the opposite direction. Calculate the angular velocity of the turntable. (Hint: use what you know about relative velocity to help solve the problem
Answer:
[tex]0.3165\ \text{rad/s}[/tex]
Explanation:
m = Mass of person = 65 kg
d = Diameter of round table = 6.5 m
r = Radius = [tex]\dfrac{d}{2}=3.25\ \text{m}[/tex]
v = Velocity of person running = 3.8 m/s
[tex]I_t[/tex] = Moment of inertia of turntable = [tex]1850\ \text{kg m}^2[/tex]
Moment of inertia of the system is
[tex]I=I_t+mr^2\\\Rightarrow I=1850+65\times 3.25^2\\\Rightarrow I=2536.5625\ \text{kg m}^2[/tex]
As the angular momentum of the system is conserved we have
[tex]L_i=L_f\\\Rightarrow mvr=I\omega_f\\\Rightarrow \omega_f=\dfrac{mvr}{I}\\\Rightarrow \omega_f=\dfrac{65\times 3.8\times 3.25}{2536.5625}\\\Rightarrow \omega_f=0.3165\ \text{rad/s}[/tex]
The angular velocity of the turntable is [tex]0.3165\ \text{rad/s}[/tex].
PLZ help 10 points!!! space question!
Answer:
3 i think
Explanation:
3. An object has 90,000 J Kinetic energy and is moving at 12m/s. What is the objects mass?
What happens when Molecules collide?
Answer:
Collision theory is used to predict the rates of chemical reactions, particularly for gases. It is based on the assumption that for a reaction to occur for the reacting species (atoms or molecules) must come together or collide with one another. Not all collisions, however, bring about chemical change.
If two molecules collide with sufficient activation energy, there is no guarantee that the collision will be successful. In fact, the collision theory says that not every collision is successful, even if molecules are moving with enough energy. The reason for this is because molecules also need to collide with the right orientation so that the proper atoms line up with one another, and bonds can break and re-form necessarily.
⦁ Determining the magnetic flux, A rectangular piece of stiff paper measures 10 cm x 5 cm. You hold the piece of paper in a uniform magnetic field that has a magnitude of 4.0 x10-3 T For each situation below, - sketch a diagram showing the magnetic field and the paper, - determine the magnitude of the magnetic flux through the paper, when the magnitude of the flux is (a) maximized (b) minimized (c) halfway between its maximum and minimum value, when the angle between the magnetic field lines and the area normal vector is 300
Answer:
jguewjdofe
Explanation:
a student throws a 140 g snowball at 8.5 m/s at the side of a schoolhouse, where it hits and sticks. what is the magnitude of the average force on the wall if the duration of the collision is .16 s?
Answer:
7.4375N
Explanation:
According to Newtons second law
F = ma
m is the mass = 140g = 0.14kg
Get the acceleration
v = u + at
8.5 = 0+0.1a
a = 8.5/0.16
a = 53.125m/s²
Get the required force
F = 0.14 * 53.125
F = 7.4375N
Hence the magnitude of the average force on the wall is 7.4375N
The fictional rocket ship Adventure is measured to be 65 m long by the ship's captain inside the rocket.When the rocket moves past a space dock at 0.5c. As rocket ship Adventure passes by the space dock, the ship's captain flashes a flashlight at 1.20-s intervals as measured by space-dock personnel.
Required:
How often does the flashlight flash relative to the captain?
Answer:
1.04 s
Explanation:
The computation is shown below:
As we know that
t = t' × 1 ÷ (√(1 - (v/c)^2)
here
v = 0.5c
t = 1.20 -s
So,
1.20 = t' × 1 ÷ (√(1 - (0.5/c)^2)
1.20 = t' × 1 ÷ (√(1 - (0.5)^2)
1.20 = t' ÷ √0.75
1.20 = t' ÷ 0.866
t' = 0.866 × 1.20
= 1.04 s
The above formula should be applied
PLEASE HELP
Which of the following are examples of gravity in action? Select all that apply.
A. an earthquake
B. a planet orbiting the sun
C. a ball flying through the air
D. precipitation falling to Earth