How many states of matter are there?
Answer:
3
Explanation:
state of matter are solid
liquid and
gases
A car travelling at 79.3 Km/h on a highway has 4.22x10 5 J of kinetic energy.
a. What is the mass of the car?
b. If brakes are applied with a force of 2100 N, what distance will it take for the car to slow down to a speed of 56 Km/h?
Answer:
[tex]1.74\times10^3 kg; 100m[/tex]
Explanation:
Step a: mass of the car. Let's grab the definition of kinetic energy: [tex]K= \frac12 mv^2[/tex]. We have K, we have v (which we should convert in meters per second, dividing by 3.6) to get:[tex]4.22\times10^5 = \frac12m(22.03)^2 \rightarrow m= 2\times4.22 / 495.22 \times 10^5 = 1.74 \times 10^3 kg[/tex]
Point a is done.
Now for the (b)reaking part. (I'm sorry, it's an horrible joke, but I couldn't resist)
In theory we have the mass, we have the force, so we could find the acceleration, find how long it takes to slow down, and then find the distance traveled. Too long. Let's do things more easily: when the car slows down to 56 km/h it will have a different kinetic energy. The difference in kinetic energy is the work done by the breaking force ofer the slowing distance.
[tex]K_f-K_i=W[/tex] A quick note on signs: if you look carefully the final kinetic energy will be less than the initial value, thus the work will be negative: it means it's correct, since the work is against the motion, slowing it down. Let's get calculating, first by converting 56 kmh in m/s (15,56 m/s), then finding the final kinetic energy:
[tex]K_f =\frac12 (1.74\times10^3) (15.56)^2 =2.11 \times 10^5 J[/tex]
The difference will be the work done by the force, or
[tex](2.11 - 4.22) \times 10^5 = \vec F\cdot \vec x=Fx[/tex] where we are assuming that force and displacement have the same line of actions to simplify the dot product.
[tex]2.11\times 10^5 = 2100x = 1.00\times 10^2 m[/tex]
Velocity and Acceleration Quick Check
Item 1
Use this graph of velocity vs. time for two objects to answer the question.
Item 2
Item 3
С
Item 4
Item 5
D
velocity
time
Which statement makes an accurate comparison of the motions for objects C and D?
(1 point)
lol
Answer:it’s C
Explanation:
by using graph of velocity vs. time for two objects, Item 4 and Item 5 statement makes an accurate comparison of the motions for objects. thus option C is correct.
What is velocity ?
velocity is the rate of change of the position of the object with respect to reference and it is complicated but velocity is basically speeding a particular object in a specific direction.
Velocity is a vector quantity which means both magnitude (speed) and direction are combinedly define define velocity. The SI unit of velocity is meter per second (ms-1) and the magnitude or the direction of velocity of a body changes leads to acceleration.
Speed and velocity are the two closest term but the major difference between speed and velocity is that speed gives us an idea that the object with the faster rate of movement r where as velocity speed up as well as tells us the direction of the body
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A student that is running in a gym at a speed of 3.5m/s grabs the rope hanging from the ceiling and swings on it.
a. how high will he swing? [63cm]
b. How high will he be when his speed reduced to half of its initial value? [16cm, ¼ of the initial value]
Can someone explain the logic behind the second part of the question (why is it 1/4 the initial value)?
a. Assuming all energy involved is conserved, at the lowest point of the swing (which includes the moment the student grabs the rope), the student only has kinetic energy,
K = 1/2 m (3.5 m/s)²
and at the highest point of the swing, the student only has potential energy
P = mgh
The energies at the bottom and top of the swing must be equal, so
1/2 m (3.5 m/s)² = mgh
h = (3.5 m/s)² / (2g)
h = 0.625 m ≈ 63 cm
b. In part (a), we found the relationship
h = v²/(2g)
If we cut the speed v in half, we replace v in the equation above with v/2 :
h = (v/2)²/(2g)
and simplifying this gives
h = (v²/4)/(2g) = 1/4 • v²/(2g)
The factor of 1/4 tells you that reducing the speed by a factor of 1/2 reduces the height by a factor of 1/4. So he can swing as high as
1/4 (3.5 m/s)²/(2g) = 0.15625 m ≈ 16 cm
A golfer hits golf ball, imparting to it an initial speed of 53 m/s directed 27° above the horizontal. Assuming that the
mass of the ball is 41g and the club and the ball are in contact for 1.0 ms. Find
b) the direction of the average force exerted on the ball by the club:
Answer:
Explanation:
An impulse results in a change of momentum
FΔt = mΔv
F = mΔv/Δt
F = 0.041(53 - 0) / 0.001
F = 2,173 N 27° above horizontal
Can anyone help me with question 10 a.
Answer:
it's ahfdfhhh hhgfdjjjjuyggffdddcff
a convex mirror and a plane mirror both give virtual and erect images still a convex mirror is used in vehicles. why?
Pls answer thiss
Answer:Convex mirrors are used because these mirrors provide a wider viewing angle than a plane mirror. This wide angle will help you getting more information/overview than what is happening at a narrow spot right behind the car if you use a plane mirror.
With a convex mirror you are for example able to detect an overtake (by the car behind you) early, if you for some reason wanted to turn left into another lane at the same moment the overtake took place - so you then can prevent a collision. Convex mirrors are simply covering a much larger area behind the car than plane mirrors do. And in the US, on the mirrors there is a text explaining that the vehicle behind you is closer than it appears - some kind of an idiot explanation in case some driver took the mirror image literally….because in the mirror image of a convex mirror, everything looks smaller and further away than they actually are.
Explanation: mark me as brainliest this is my best answer till now
The photo shows a skateboarder pushing her foot against the ground as she rides down a hill.
How does this action cause the skateboarder’s speed to change?
Answer:
A
Explanation:
Down the hill, the net force increases if she pushes more forward.
Answer:
its a im just did the test
Explanation:
This is for Lipor only.
Answer:
im here\
Explanation:
What is the difference between the contagion theory and the convergence
theory?
O A. One deals with how people behave before a riot, and the other
deals with how people behave after a riot.
O B. One deals with adults with no power, and the other deals with
authority figures.
O C. One deals with how people are affected by a crowd, and the other
deals with how people actively drive a crowd's Behavior.
O D. One deals with people from democratic governments, and the
other deals with people from authoritarian governments.
Answer: Contagion theory states that crowds cause people to act in a certain way; convergence theory says the opposite, claiming that people who wish to act in a certain way come together to form crowds.
Explanation: Its C
After an unfortunate accident occurred at a local warehouse, you were contracted to determine the cause. A jib crane collapsed and injured a worker. An image of this type of crane is shown in the figure.The horizontal steel beam had a mass of 88.50 kg
per meter of length, and the tension in the cable was =11650 N
. The crane was rated for a maximum load of 500 kg
. If =5.580 m
, =0.522 m
, =1.350 m
, and ℎ=2.070 m
, what was the magnitude of L
(the load on the crane) before the collapse? The acceleration due to gravity is =9.810 m/s2
The magnitude of the load L on the crane before the collapse is 3211.81 N
To determine the magnitude of the load on the crane (L), we will need to make use of the equilibrium conditions of the torque.
It is always an ideal process to list out all the parameters given as this will let you understand how you can determine the answer to the question from the given parameters.
From the given information;
The tension in the cable = 11650 NThe length (d) = 5.580 mThe mass of the horizontal steel beam (M) = 88.50 kg/m (d)= 88.50 kg/m × 5.580 m= 493.83 kgDistance (s) = 0.522 mx = 1.350 m and h = 2.070 mAcceleration due to gravity = 9.81 m/s²From the question;
the angle at which the crane is positioned can be determined by taking the tangent of the angle θ. i.e.
[tex]\mathbf{tan \ \theta = \dfrac{h}{d-s}}[/tex]
[tex]\mathbf{\theta = tan^{-1} \Big ( \dfrac{h}{d-s} \Big )}[/tex]
[tex]\mathbf{\theta = tan^{-1} \Big ( \dfrac{2.070 }{5.580 - 0.522} \Big )}[/tex]
[tex]\mathbf{\theta =22.26^0}[/tex]
Consider the equilibrium conditions of the torques with respect to the magnitude of the load at point P.
∴
[tex]\mathbf{Tsin \theta (d-s) - W_L (d-x) -(Mg) (\dfrac{d}{2}) = 0}[/tex]
By making the magnitude of the load [tex]\mathbf{W_L}[/tex] the subject of the formula, we have:
[tex]\mathbf{W_L = \dfrac{Tsin \theta (d-x) -(Mg) (\dfrac{d}{2})}{ (d-s) } }[/tex]
[tex]\mathbf{W_L = \dfrac{(11650 )sin (22.26) (5.580-1.350) -(88.50\times 9.81) (\dfrac{5.580}{2})}{ (5.580-0.522) } }[/tex]
[tex]\mathbf{W_L = 3211.81 \ N }[/tex]
Therefore, we can conclude that the magnitude of the load is 3211.81 N
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2. Which of the following contributions did Louie De Broglie do for electronic structure of matter? A. determined the speed of electron of hydrogen atom B. proposed a theory that electrons showed characteristics similar to light C. provided mathematical operation for the characteristics of light D. recorded the movement of proton in the nucleus of an atom
❤️
Answer:
In 1924 Louis de Broglie introduced the idea that particles, such as electrons, could be described not only as particles but also as waves. This was substantiated by the way streams of electrons were reflected against crystals and spread through thin metal foils.
Explanation:
I know I probably didn't answer your question, I just used all of my knowledge that I learned about Louie De Broglie. Hope it helps!
A 64 kg student is standing atop a spring in an
elevator that is accelerating upward at 3.0 m/s2
The spring constant is 3000 N/m.
A) by how much is the spring compressed?
Answer:
192
Explanation:
What type of equilibrium maintains body position during sudden motion?
dynamic
rotational
static
balanced
I think static is the correct answer
A flywheel, rotating about its axis at a rate of 4 rev/s is acted upon by a torque of 25 Nm for 10 sec. If the wheel has moment of inertia of 1.2 kgm^2, what would be the speed of the wheel at the end in rev/s?
The applied torque increases the angular speed by the application of an
angular acceleration.
The speed after 10 seconds is approximately 37.16 rev/s.Reasons:
The speed of the flywheel at the axis = 4 rev/s
The torque applied, T = 25 N·m
The time the torque is applied, t = 10 sec
Moment of inertia of the flywheel, I = 1.2 kg·m²
Required:
The speed at the end of the 10 seconds
Solution:
T = I·α
Where;
α = Angular acceleration
[tex]\displaystyle \alpha = \frac{T}{I}[/tex]
Therefore;
[tex]\displaystyle \alpha = \frac{24 \ N\cdot m}{1.2 \ kg \cdot m^2} = \mathbf{20\frac{5}{6} \ s^{-2}}[/tex]
The rotational speed, ω = ω₀ + α·t
Which gives;
[tex]\displaystyle \mathrm{The \ angular \ speed, } \ \omega = \frac{2 \cdot \pi \times 4 \ rad }{s} = \frac{8 \cdot \pi \ rad }{s}[/tex]
ω₀ = 8·π rad/s
Which gives;
[tex]\displaystyle \omega = \mathbf{8 \cdot \pi +2 \frac{5}{6} \times 10} = 233.47[/tex]
The speed of the wheel in revolution per second is therefore;
[tex]\displaystyle Speed \ in \ rev/s = \frac{8 \cdot \pi +2 \frac{5}{6} \times 10}{2\cdot \pi} \approx 37.16[/tex]
The speed after 10 seconds is approximately 37.16 rev/s.
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Determine the unbalanced force necessary to accelerate a 2.60 kg object at a rate of 14.0 m/s².
Answer:
Explanation:
F = ma
F = 2.60(14.0)
F = 36.4 N
The elevation at the base of a ski hill is 350 m above sea level. A ski lift raises a skier (total mass=72 kg, including equipment) to the top of the hill. If the skier's gravitational potential energy relative to the base of the hill is now 9.2 x 105 J, what is the elevation at the top of the hill?
The elevation at the top of the hill is 1,653.85 m.
The given parameters;
initial height of the skier, h₁ = 350 mlet the final height of the skier at the hill top, = h₂total mass, m = 72 kggravitational potential energy of the skier, P.E = 9.2 x 10⁵ JThe elevation at the top of the hill is calculated as follows;
[tex]P.E = mg\Delta h\\\\P.E = mg(h_2 -h_1)\\\\h_2 -h_1 = \frac{P.E}{mg} \\\\h_2 = \frac{P.E}{mg} + h_1\\\\h_2 = \frac{9.2 \times 10^5 }{72 \times 9.8} \ + \ 350 \ m\\\\h_2 = 1,653.85 \ m[/tex]
Thus, the elevation at the top of the hill is 1,653.85 m.
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if fire needs oxygen to burn, where does the sun get oxygen if there is no oxygen in space?
The sun is not a burning fire.
It's much much much hotter than that.
The sun's energy is the result of continuous nuclear fusion in it's core. We know how to do that on Earth, but the only thing we've been able to use it for so far is hydrogen bombs and other thermonuclear weapons.
numerical problems:
a.) convert 300K into the celsius scale.
b.) convert 220 centigrade scale into kelvin scale.
c.) convert 20 ventigrade scale into Fahrenheit scale.
d.) convert 260 Fahrenheit into centigrade. pls help me to solve this problems
Four small 0.600-kg spheres, each of which you can regard as a point mass, are arranged in a square 0.400 m on a side and connected by light rods. Find the moment of inertia of the system about an axis through the center of the square, perpendicular to its plane at point O.
Answer:
.192 kg x m^2
Explanation:
I= mass of a times radius of a squared + mass of b times radius of b squared +...
I= .6 kg x .4m^2 + .6 kg x .4m^2
= .192 kg x m^2
Hope this helps :)
Tectonic plate movement is the reason why northern California has a very different landscape than southern California. Two different tectonic plates, each moving in different directions, border the western side of the North American Plate. Use the map to identify the two tectonic plates that border the North American Plate to the west.
Answer:
Remember, NORTH ^, EAST >, SOUTH v, WEST <
Explanation:
It doesn't have to be a super complex answer. All you have to do is look to the left (west) of the North American plate. What are the 2 plates that you see? The Pacific and the Juan de Fuca, yeah? To the South, there is the Cocos amongst a few others.
I am not going to share the answer for sure as I haven't completed the test yet but that's how I'm solving it. You should write the answer in your own words anyways. Hope this helps! Have a good day :)
Answer:
The Juan de Fuca Plate and the Pacific Plate both border the west side of the North American Plate.
Explanation:
Edmentum
A domestic water heater holds 189 L of water at 608C, 1 atm. Determine the exergy of the hot water, in kJ. To what elevation, in m, would a 1000-kg mass have to be raised from zero elevation relative to the reference environment for its exergy to equal that of the hot water
A.
The energy of the hot water is 482630400 J
Using Q = mcΔT where Q = energy of hot water, m = mass of water = ρV where ρ = density of water = 1000 kg/m³ and V = volume of water = 189 L = 0.189 m³,
c = specific heat capacity of water = 4200 J/kg-°C and ΔT = temperature change of water = T₂ - T₁ where T₂ = final temperature of water = 608 °C. If we assume the water was initially at 0°C, T₁ = 0 °C. So, the temperature change ΔT = 608 °C - 0 °C = 608 °C
Substituting the values of the variables into the equation, we have
Q = mcΔT
Q = ρVcΔT
Q = 1000 kg/m³ × 0.189 m³ × 4200 J/kg-°C × 608 °C
Q = 482630400 J
So, the energy of the hot water is 482630400 J
B.
The elevation the mass would have to be raised from zero elevation relative to the reference environment for its exergy to equal that of the hot water is 49248 m.
Using the equation for gravitational potential energy ΔU = mgΔh where m = mass of object = 1000 kg, g = acceleration due to gravity = 9.8 m/s² and Δh = h - h' where h = required elevation and h' = zero level elevation = 0 m
Since the energy of the mass equal the energy of the hot water, ΔU = 482630400 J
So, ΔU = mgΔh
ΔU = mg(h - h')
making h subject of the formula, we have
h = h' + ΔU/mg
Substituting the values of the variables into the equation, we have
h = h' + ΔU/mg
h = 0 m + 482630400 J/(1000 kg × 9.8 m/s²)
h = 0 m + 482630400 J/(9800 kgm/s²)
h = 0 m + 49248 m
h = 49248 m
So, the elevation the mass would have to be raised from zero elevation relative to the reference environment for its exergy to equal that of the hot water is 49248 m.
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what two things make up an ionic bond?
I need help been struggling on this question
Answer:
440 m
Explanation:
S=(u+v) t / 2
S = (11+33) × 20/2
S= 44× 20/2
S=440 m
Objects 1 and 2 attract each other with a gravitational force of 45 units. If the mass of Object 1 is doubled, then the new gravitational fore will be ______ units.
Explanation:
Fgravity = G*(mass1*mass2)/D²
so, if you double one of the masses, what does that do to our equation ?
Fgravitynew = G*(2*mass1*mass2)/D²
due to the commutative property of multiplication
Fgravitynew = 2* G*(mass1*mass2)/D² = 2* Fgravity
so, the correct answer will be 2×45 = 90 units.
The elevation at the base of a ski hill is 350 m above sea level. A ski lift raises a skier (total mass=72 kg, including equipment) to the top of the hill. If the skier's gravitational potential energy relative to the base of the hill is now 9.2 x 105 J, what is the elevation at the top of the hill?
The elevation at the top of the hill is 1,653.85 m.
The given parameters;
initial height of the skier, h₁ = 350 mlet the final height of the skier at the hill top, = h₂total mass, m = 72 kggravitational potential energy of the skier, P.E = 9.2 x 10⁵ JThe elevation at the top of the hill is calculated as follows;
[tex]P.E = mg\Delta h\\\\P.E = mg(h_2 -h_1)\\\\h_2 -h_1 = \frac{P.E}{mg} \\\\h_2 = \frac{P.E}{mg} + h_1\\\\h_2 = \frac{9.2 \times 10^5 }{72 \times 9.8} \ + \ 350 \ m\\\\h_2 = 1,653.85 \ m[/tex]
Thus, the elevation at the top of the hill is 1,653.85 m.
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The symbol delta x (x) is used to find what value?
Answer:
Explanation:
Δx means a change in the magnitude of the x variable, often used in reference to a number line on the horizontal axis of a plot.
Who is Albert Einstein?
Answer:
Albert Einstein WAS a very well known Theoretical physicist
The USA claims he did not ever get his hands directly on an atomic bomb but in fact, other country textbooks like in Germany say he did.
Explanation:
A fun fact is that he was hired by the United States to make the Atomic bomb. Albert Einstein was a german yet many believed him to be a Smart American, they were wrong.
Which performs a function that is most like the function of a retina?
Answer:
The answer is ciliary body and focus the pupil. In addition, the ciliary body is a portion of the eye that contains the ciliary muscle that reins the shape of the lens and the ciliary epithelium that yields the aqueous humor. The ciliary body is a share of the uvea which is the layer of tissue that transports oxygen and nutrients to the eye nerves while the pupil is a hole positioned in the midpoint of the iris of the eye that permits light to foray the retina. It looks black since light rays incoming the pupil are moreover engrossed by the tissues in the eye openly or engrossed after diffuse reflections in the eye that typically miss leaving the fine pupil
Explanation:
Answer:the eye has many parts that must work together in order to produce clear vision
Explanation: correct on my test
help me in the Infer one
Answer:
Overcurrents
Circuit breakers ("fuses" back in the day) are supposed to trigger when you are requesting past it more power (thus more current, since the tension is fixed and power is the product of voltsge times current). So whoever made that part of the grid did not foresee that many appliances.
Another option could be a short circuit somehwere but I think it is unlikely since the breaker would not trigger only when all three loads are powered on.