Answer:
Explanation:
a ) The angle required = angle of repose = θ
Tanθ = .81
θ = 39⁰
b ) when angle of incline θ = 44
Net force on the block = mg sinθ - μ mg cosθ where μ is coefficient of kinetic friction
acceleration = gsinθ - μ g cosθ
= 9.8 ( sin44 - μ cos44 )
= 9.8 ( .695 - .69 x .72 )
= 9.8 ( .695 - .497 )
= 1.94 m /s²
A 12-volt battery maintains a 4.5A current through a resistor. What is the resistance of the resistor.
A squirrel falls from this tree after being shocked by the falling apples. If the
squirrel was 3.5 meters above the ground, how long until the squirrel hits the
ground?
Answer:
0.85m
Explanation:
Given parameters:
Height of fall = 3.5m
Unknown:
Duration of fall = ?
Solution:
To solve this problem, we apply the right motion equation.
Since we know the height, we can use the equation below;
S = ut + [tex]\frac{1}{2} gt^{2}[/tex]
S is the height
u is the initial velocity = 0m/s
t is the time
g is the acceleration due to gravity
3.5 = 0 + [tex]\frac{1}{2}[/tex] x 9.8 x t²
3.5 = 4.9t²
t² = [tex]\frac{3.5}{4.9}[/tex]
t² = 0.71
t = √0.71 = 0.85m
A rotating wheel requires 8.00 s to rotate 27.0 revolutions. Its angular velocity at the end of the 8.00-s interval is 99.0 rad/s. What is the constant angular acceleration (in rad/s) of the wheel?
Answer:
∝ = 28.92 rad/s²
Explanation:
Applying third equation of motion to the angular motion, we have:
2∝θ = ωf² - ωi²
where,
∝ = angular acceleration = ?
θ = angular displacement = (27 rev)(2π rad/1 rev) = 169.64 rad/s
ωf = final angular velocity = 99 rad/s
ωi = initial angular velocity = 0 rad/s
Therefore,
(2)∝(169.64 rad) = (99 rad/s)² - (0 rad/s²)
∝ = (9801 rad²/s²)/(38.8 rad)
∝ = 28.92 rad/s²
How would you go about measuring the speed of a vehicle? What measurements would you have to take? What calculations would you have to perform?
Answer:
For a body moving at a uniform velocity you can calculate the speed by dividing the distance traveled by the amount of time it took, for example one mile in 1/2 hour would give you 2 miles per hour. If the velocity is non-uniform all you can say is what the average speed is.
Pete is driving down 7th Street. He drives 300 meters in 18 seconds. Assuming he does not speed up or slow down, what is his speed in meters per second? Round answer to the hundredths place.
Answer:
16.67m/s
Explanation:
Given parameters:
Distance Pete drove = 300m
Time taken = 18s
Unknown:
Speed = ?
Solution:
Speed is the distance traveled per unit of time.
It is mathematically expressed as;
Speed = [tex]\frac{distance}{time}[/tex]
Insert the parameters and solve;
Speed = [tex]\frac{300}{18}[/tex] = 16.67m/s
Kathryn decides to take her dog for a walk one day. Her dog tries pulling on her with a force of 15N. Kathryn pulls back with force of 20N. What is the net force?
Assuming both forces act horizontally, the net force is in Kathryn's direction with a magnitude of 5 N.
If "towards Kathryn" is taken the be the positive direction, then the net force is
∑ F = 20 N - 15 N = 5 N
The first excited state of a particular atom in a gas is 5.8 eV above the ground state. A moving electron collides with one of these atoms, and excites the atom to its first excited state. Immediately after the collision the kinetic energy of the electron is 3.7 eV. What was the kinetic energy of the electron just before the collision?
Ki = ____eV
Answer:
E₀ = 9.5 eV
Explanation:
In the processes of absorption, excitation and shocks the energy must be conserved therefore the energy before the shock is
E₀ = E_excitation + E_residual
E₀ = 5.8 + 3.7
E₀ = 9.5 eV
this is the energy of the electron before the collision
An airplane with a mass of 5,000 kg needs to accelerate 5 m/s2 to take off before it reaches the end of the runway. How much force is needed from the engine
Answer:
25000 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 5000 × 5
We have the final answer as
25000 NHope this helps you
: To determine the focal length of a lens, the following except _ is needed
Answers options
Needles
Siphon
Converging Lens
Diverging Lens
A ball connected to a 1.1 m string and is swing in circular fashion. It’s tangential velocity is 15 m/s. What is its centripetal acceleration?
Answer:
ac = 204 [m/s²]
Explanation:
To solve this problem we must use the following equation that relates the tangential velocity to the radius of rotation.
ac = v²/r
where:
v = tangential velocity = 15 [m/s]
r = radius = 1.1 [m]
Now replacing we have:
ac = (15)²/1.1
ac = 204 [m/s²]
Which of the following is not one of the four muscle shapes?
A. Triangular
B. Flat
C. Spindle
D. Cylindrical
Answer:
When elements bond together or when bonds of compounds are broken and form a new substance
Explanation:
Which is an example of a chemical change?
1.
How does centripetal force due to gravity keep a satellite in orbit?
It continuously changes the direction of the satellite.
It provides the thrust to launch the satellite into space.
It prevents the satellite from falling toward Earth.
It keeps increasing the speed of the satellite.
Answer:
1st one,.
It changes the direction,
And satellite falls in earth infinity,
Its total workdone is zero
Answer:
It continuously changes the direction of the satellite.
Explanation:
our Welcome (; (:
2.
Which statement is true regarding the launch of a rocket?
The downward force of the rocket exhaust is greater than the upward force on the rocket.
The downward force of the rocket exhaust is equal to the upward force on the rocket.
The upward force of the rocket exhaust is equal to the downward force on the rocket.
The downward force of the rocket exhaust is less than the upward force on the rocket.
Answer:
First one,
Its because
Downward force must greater to uplift its weight.
From 3rd law of motion
Answer:
The downward force of the rocket exhaust is greater than the upward force on the rocket.
Explanation:
Your Welcome (;
A skateboarder is moving at 2.00m/s and increases his velcity at a rate of 1.6m/s/s for 6.0 seconds. What is the displacement of the skateboarder during this game? Must include Given, Find , and Equation. Show all work .
Answer:
S = 40.8m
Explanation:
Given the following data;
Initial velocity, u = 2m/s
Acceleration, a = 1.6m/s²
Time, t = 6secs
Required to find the displacement
Displacement, S = ?
The displacement of an object is given by the second equation of motion;
[tex] S = ut + \frac {1}{2}at^{2}[/tex]
Where;
S represents the displacement measured in meters. u represents the initial velocity measured in meters per seconds. t represents the time measured in seconds. a represents acceleration measured in meters per seconds square.Substituting into the equation, we have;
[tex] S = 2*6 + \frac {1}{2}*(1.6)*6^{2}[/tex]
[tex] S = 12 + 0.8*36[/tex]
[tex] S = 12 + 28.8 [/tex]
S = 40.8m
Therefore, the displacement of the skateboarder during this game is 40.8 meters.
Object A is 71 degrees and object B is 75 degrees how will thermal energy flow
Given :
Object A is 71 degrees and object B is 75 degrees .
To Find :
How will thermal energy flow.
Solution :
We know, by law of thermodynamics thermal energy will flow from higher temperature to lower temperature.
So, in the given question energy will flow from object B from object A.
Hence, this is the required solution.
If the sound source is moving then the pitch of the sound will ___________________ to the observer.
Answer:
Increase
Explanation:
The frequency of sound determines the sound. If the frequency is lower the pitch will be lower. If the frequency is higher the pitch will be higher. This is affected by the motion of the sound source because when a sound source is moving faster the frequency will become higher.
6. Which of the following types of energy is not lost when energy is
transferred between one of the Earth's four physical systems?*
heat
light
sound
nuclear
vibration
movement
Answer:
heat light sound viberation
Explanation:
i'm built different
Maria wrote the following steps in the formation of igneous rocks. Step 1: Rocks pushed under Earth due to movement of tectonic plate Step 2: Rocks melt Step 3: Molten rocks are heated Step 4: Rocks solidify Which step contains an error?
Answer:
Step 1: Rocks pushed under Earth due to movement of tectonic plate
Step 2: Molten rocks are heated
Step 3: Rocks melt
Step 4: Rocks solidify
Explanation:
Step 1: Rocks pushed under Earth due to movement of tectonic plate
Step 2: Rocks melt
Step 3: Molten rocks are heated
Step 4: Rocks solidify
In the formation of igneous rocks, rocks are pushed under the earth due to the movement of tectonic plate.
As the rocks are pulled beneath the crust, they are heated and begin to melt to form magma.
Then, with time, the magma solidify to form an igneous rock.
Step 2 is wrong.
Step 3 should come first
Step 1: Rocks pushed under Earth due to movement of tectonic plate
Step 2: Molten rocks are heated
Step 3: Rocks melt
Step 4: Rocks solidify
what is the difference of dispersed phase and continuous phase?
Answer:
The phase existing as small droplets is called the dispersed phase and the surrounding liquid is known as the continuous phase. Emulsions are commonly classified as oil-in-water (O/W) or water-in-oil (W/O) depending on whether the continuous phase is water or oil.
Explanation:
A Carnot engine takes in heat at a temperature of 790 K and releases heat to a reservoir at a temperature of 470 K. What is its efficiency?
Answer: 1280 kilometers :D
Explanation:
790 K ' 470 K = 1280 KM (KILOMETERS)
Answer:
GIVE DIS GUY BRAINLIST
Explanation:
Try to move the magnet back and forth between the two coils. Explain the motion of the magnet and what might be causing this.
Answer:
Please find the answer in the explanation.
Explanation:
When you try to move the magnet back and forth between the two coils, the motion of the magnet will be oscillatory and this action will cause current and EMF to induce
According to law of Faraday, current or EMF will be induced when a magnet is moved in the presence of coils
If the magnet continues to move back and forth between the two coils, what might be causing this will be the presence of the induced electromagnetic force between the two coils.
A boy pulls his 9.0 kg sled, applying a horizontal force of 14.0 N (rightward). The coefficient of friction between the snow and the sled is 0.12. Determine the net force and the acceleration of the sled. Draw a free-body diagram for the sled; use appropriate force symbols to label the type of each force acting on the sled.
Here is the answer, dud
Telephone signals are often transmitted over long distances by microwaves. What is the frequency of microwave radiation with a wavelength of 3.5 cm?
Express your answer in GHz and using two significant figures.
f = ________GHz
Microwave signals are beamed between two mountaintops 52 km apart. How long does it take a signal to travel from one mountaintop to the other?
Express your answer in ms and using two significant figures.
t = ________ms
Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:[tex]v = \lambda * f (1)[/tex]
Replacing by the givens, and solving for f, we get:[tex]f =\frac{c}{\lambda} =\frac{3e8m/s}{0.035m} = 8.57e9 Hz (2)[/tex]
⇒ f = 8.6 Ghz (with two significative figures)
2)
Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:[tex]v =\frac{d}{t} (3)[/tex]
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
Solving for t, we get:[tex]t = \frac{d}{c} = \frac{52e3m}{3e8m/s} = 17.3e-5 sec = 0.173e-3 sec = 0.173 ms (4)[/tex]
⇒ t = 0.2 ms (with two significative figures)
the lanthanides are all radioactive true or false
Answer:
False
Explanation:
All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive.
The lanthanides belong to the f-block on the periodic tableOnly Promethium in this group are radioactive in nature. Other elements in the lanthanide series might have radioactive isotopes.A projectile is projected from the origin with a velocity of 45.0 m/s at an angle of 30.0 degrees above the horizontal. What is the velocity when the projectile hits the ground?
Answer:
velocity = 44.98 m/s
Explanation:
given data
velocity = 45.0 m/s
angle = 30.0 degrees
solution
first we get here time that is
time = 2u × sin θ ÷ g .............1
time = 2×45 × sin 30 ÷ 9.8
time = 4.59 sec
and
velocity = [tex]\sqrt{vx^2+vy^2}[/tex] .....................2
here
vx = 45 cos30 = 38.97 m/s
vy = uy - gt
vy = 45 sin30 - 9.8 × 4.59 = -22.48 m/s
so velocity will be
velocity = [tex]\sqrt{38.97^2+22.48^2}[/tex]
velocity = 44.98 m/s
The transfer of thermal energy between objects of different
temperatures is called...
A.) Heat
B.) Temperature
C.) Specific Heat
D.) Internal Energy
Answer:
A
Explanation:
heat transfer occurs between two objects that are not in thermal equilibrium (do not have the same temperature)(heat flows from hot to cold objects)
temp= measure of how hot/cold something is
internal E= total E of a closed system
The transfer of thermal energy between objects of different temperatures is called Heat.
What is heat?Heat is the energy transferred from one object to another as a result of a temperature differential. When two bodies of different temperatures come into contact, energy is transferred—that is, heat flows— towards the colder body from the hotter.
As we know that when two bodies are not in thermal equillibrium then the heat starts to flow, from the higher temperature body towards the lower temperature body. Thus, The transfer of thermal energy between objects of different temperatures is called Heat.
Learn more about Heat:
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An object falling from a great height in Earth's atmosphere eventually reaches a speed called Terminal velocity. What cause a falling object to stop increasing in speed once it reaches terminal velocity? Really struggling, I need an answer--quick. Which letter is correct and why please?
A. Its mass and weight have become equal
B. It has no more potential energy
C. No forces are acting on it any longer
D. The forces acting on it are balanced
Answer:
A.
Explanation:
If its at a height the Gratitude of it falling down with only Gravity if Any other Forces are acting on it so as Friction But Sideways.
What happens to the gravitational potential energy between two particles if the distance between them is halved? (a) It does not change(b) It is multiplied by 2(c) It is multiplied by 4(d) It is multiplied by 8What happens to the gravitational force between two particles if the distance between them is doubled? (a) It does not change(b) It decreases by a factor of 2(c) It decreases by a factor of 4(d) It decreases by a factor of 8
Answer:
The gravitational potential energy between two particles, if the distance between them is halved, is multiplied by 4 (option c).
Explanation:
The gravitational force is the force of mutual attraction that two objects with mass experience.
The Law of Universal Gravitation enunciated by Newton says that every material particle attracts any other material particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance that separates them. Mathematically this is expressed as:
[tex]F=G*\frac{m1*m2}{r^{2} }[/tex]
where m1 and m2 are the masses of the objects, r the distance between them and G a universal constant that receives the name of constant of gravitation.
If the distance between two particles is reduced by half, then, where F' is the new value of the gravitational force:
[tex]F'=G*\frac{m1*m2}{(\frac{r}{2} )^{2} }[/tex]
[tex]F'=G*\frac{m1*m2}{\frac{(r )^{2} }{2^{2} } }[/tex]
[tex]F'=G*\frac{m1*m2}{\frac{(r )^{2} }{4} }[/tex]
[tex]F'=4*G*\frac{m1*m2}{r^{2} }[/tex]
F'=4*F
The gravitational potential energy between two particles, if the distance between them is halved, is multiplied by 4 (option c).
For mechanical waves, such as sound waves or ocean waves, increasing the intensity of the wave increases both the amplitude (height) of the wave and the energy it carries. In that situation, a low-frequency but high-intensity wave should have the same effect as a high-frequency but low-intensity wave. How does light behave differently from this model?
Answer:
the effect is given by the energy that depends on the frequency, but not on the intensity
Explanation:
There are similarities and differences between mechanical waves and electromagnetic waves. The main difference is that mechanical waves depend on a material medium for their propagation, whereas electromagnetic waves are maintained by the oscillation of their electrical magnetoscope fields.
In the case of light (electromagnetic wave) the energy is given by the relation
E = h f
where h is Planck's constant and f is the frequency.
Then the intensity is given by the number of waves or quasiparticles (photons) that are in the ray.
Consequently the effect is given by the energy that depends on the frequency, but not on the intensity
The energy in the given model depends on the frequency, but not on the intensity.
The given problem is based on the mechanical wave and electromagnetic waves. The mechanical waves depend on a material medium for their propagation, whereas electromagnetic waves are maintained by the oscillation of their electrical magneto scope fields.
In the case of light (electromagnetic wave) the energy is given by the relation,
E = h f
Here,
h is Planck's constant.
And f is the frequency.
Then the intensity is given by the number of waves (photons) that are in the ray. So, it is evident the effect is given by the energy that depends on the frequency, but not on the intensity.
Thus, we can conclude that the energy in the given model depends on the frequency, but not on the intensity.
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