Answer:
The value is [tex]t =29.2 \ s [/tex]
Explanation:
From the question we are told that
Generally the average velocity of the train is mathematically represented as
[tex]v = \frac{u + v}{2}[/tex]
substituting 82.4 km/h for u and 16.4 km/h. for v
[tex]v = \frac{82.4 + 16.4}{2}[/tex]
[tex]v = 49.4 \ km/h[/tex]
Generally the time taken is mathematically represented as
[tex]t = \frac{ L}{v}[/tex]
substituting 49.4 \ km/h for v and [tex]4.00 * 10^2 \ m = 0.400 \ km[/tex]
[tex]t = \frac{ 0.400}{49.4}[/tex]
[tex]t = 0.00809 \ h [/tex]
converting to seconds
[tex]t = 0.00809 * 3600 [/tex]
[tex]t =29.2 \ s [/tex]
Which of the following quantities represent mass?
a. 12.0 lbs.
b. 0.34 g.
c. 120 kg.
d. 1600 kN.
e. 0.34 m.
f. 411 cm.
g. 899 MN.
Answer:
Explanation:
a ) 12.0 lbs - mass
b ) .34 g - mass
c ) 120 kg - mass
As lbs , g and kg are units of mass , these things represent mass . lbs is FPS unit of mass and kg is SI unit . g is CGS unit of force .
d ) 1600 kN It represents force because kN or kilonewton is unit of force .
e ) it represents , length or distance because m or metre is unit of length .
f ) 411 cm It represents length or distance because cm is smaller unit of length
g ) 899 MN or million newton . Like d ) It also represents force . Million newton is higher unit of force .
During which step of the scientific method does a scientist make an educated
guess about the outcome of an experiment?
A. Collect data
B. Form a hypothesis
C. Analyze the results
O D. Design an experiment
SUBNA
Answer:B. Form a hypothesis
What is the key difference between acentralized electrical distribution grid versus a distributed electrical distribution grid? I am using the textbook provided but I can not find an answer
The electricity generated by centralized generation is distributed through the electric power grid to multiple end-users. Centralized generation facilities include fossil-fuel-fired power plants, nuclear power plants, hydroelectric dams, wind farms, and more.
A marathon runner runs at a steady 15 km/hr. When the runner is 7.5 km from the finish, a bird begins flying from the runner to the finish at 30 km/hr. When the bird reaches the finish line, it turns around and flies back to the runner, and then turns around again, repeating the back-andforth trips until the runner reaches the finish line. How many kilometers does the bird travel?
Answer:
The value is [tex]D = 15 \ km [/tex]
Explanation:
From the question we are told that
The speed of the marathon runner is [tex]v = 15 \ km /hr[/tex]
The distance from the distance from the finish is [tex]d = 7.5 \ km[/tex]
The speed of the bird is [tex]v_b = 30 \ km / hr[/tex]
Generally the time taken for the runner to reach the finish is mathematically represented as
[tex]t = \frac{d}{v}[/tex]
[tex]t = \frac{7.5}{15}[/tex]
[tex]t = \frac{1}{2}[/tex]
So the distance covered by the bird is
[tex]D = v_b * t[/tex]
[tex]D = 30 * \frac{1}{2}[/tex]
[tex]D = 15 \ km [/tex]
There are two ways that an object can get in motion. What are they?
Answer:
pull or pushExplanation:
According to Newton's first law of motion "An object will continue to stay or remain at rest or continue to be in constant motion "unless acted upon by an external force"
F= ma
Basically a force is a pull or a push
so in other words the two ways by which an object can get in motion is by
1. A pull force
2. A push force
The rifles in the figures are being fired horizontally (straight outward, off platforms). The bullets fired from the rifles are all identical, but the rifles propel the bullets are different speeds. The speed of each bullet and the height of each platform are given. All the bullets miss their targets and hit the ground. Rank the time it takes the bullets to hit the ground. Explain your reasoning.
Answer:
t = √ 2y₀ / g
if they are at the same height, all the bullets must carry the target, since when advancing the height decreases
Explanation:
In this exercise we see that the bullets are fired horizontally so the time it takes to reach the ground is
y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
as they are fired horizontally their vertical velocity is zero and the height upon reaching the ground is zero y = 0
0 = y₀ - ½ g t²
t = √ 2y₀ / g
from here we can see that the time it takes for the bullets to hit the floor depends only on the initial height
Therefore, all the bullets that come out of the same height reach the ground at the same time, but at a different distance, so if one misses the target, everything must fail since reaching the target is below the initial height.
The horizontal distance traveled by the bullets is
x = v₀ₓ t
v₀ₓ =v₀
x = v₀ √2y₀/g
For a more precise calculation we should know the height of the target and the bullets, but if they are at the same height, all the bullets must carry the target, since when advancing the height decreases
The voltage across a 8.5-F capacitor is 2te–3t V. Find the current and the power.
Answer:
Explanation:
Given the capacitance of a capacitor = 8.5F
Voltage across the capacitor = 2te^-3tV
The current across a capacitor is expresses as shown;
I = Cdv/dt
Given V = 2te^-3tV
dv/dt = 2t(-3e^-3t) + 2(e^-3t)
dv/dt = -6te^-3t + 2e^-3t
Factor out the common term
dv/dt = -2e^-3t{3t-1}
If C = 8.5F
I = 8.5 × -2e^-3t{3t-1}
I = -17.0e^-3t{3t-1} A
Power is the product of current and voltage.
P = IV
Given I = -17.0e^-3t{3t-1} A
V = 2te^-3t V
Power = -17.0e^-3t{3t-1} × 2te^-3t
Power = (17e^-3t - 51te^-3t) × 2te^-3t
Power = 34te^{-3t-3t} - 102t²e^{-3t-3t}
Power = 34te^-6t - 102t²e^-6t
Power = 34te^-6t{1-3t} Watts
what part of the stem cell provides instructions for building the heart
a. ribosomes
b. DNA
c. RER
d. lysosomes
A car is on a cruise control driving in a circle. Which are constant and which are changing? Speed, Velocity. Is the car accelerating?
Answer:
Only the speed is constant.
The acceleration and velocity are changing.
Explanation:
The velocity of an object refers to its speed in a specific direction. Due to the fact that the car is driving in a circle, the direction of the car is changing. This makes the car not to have a constant velocity as this value changes each time the car makes a bend on the circular path. (which is pretty much all the time).
The acceleration is a direct derivative of the velocity of the car. As a result, if the velocity is changing, the acceleration is also changing.
Speed is a scalar quantity. This means it does not deal with the direction of the car. It only deals with how fast the car is moving. The car is on cruise control. this means that the speed of the car does not change.
Saturn is 890,700,000 miles from the Sun. What is this distance in scientific notation? The ratio of miles to meters is 1 mile equals 1.61 x 103 meters. What is this distance in meters? If the speed of light is 3.0 x 108 meters/second, how long does it take for light from the Sun to reach Saturn? Hint: Use the distance in meters to calculate.
Answer:
13 hours, 16 minutes, 41 seconds
Explanation:
Distance of Saturn from the Sun
= 890,700,000 miles
[tex] = 8.907\times 10^8 \: miles\\
= 8.907\times 10^8 \times 1.61 \times 10^3 \:meters\\
= 14.34027\times 10^{11}\: m\\
= 1. 434027\times 10^{12}\: m\\\\
\because Time = \frac{Distance}{Speed} \\
\therefore Time = \frac{1.434027\times 10^{12}}{3\times 10^8}\\
\therefore Time = 4.78009 \times 10^{12-8}\\
\therefore Time = 4.78009 \times 10^{4} \:seconds \\
\therefore Time = 47800.9 \:seconds\\
\therefore Time = 47801 \:seconds\\
\therefore Time = 13h\: 16m\: 41s\\[/tex]
Saturn is 890,700,000 miles from the Sun. This distance in the scientific notation would be 1.434×10¹² metes.
If the speed of light is 3.0 x 108 meters/second, then it would take 4780 seconds for light from the Sun to reach Saturn.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. It depends on the magnitude as well as the direction of the moving object. The unit of velocity is meter/second. It can also be represented by the infinitesimal rate of change of displacement with respect to time. The generally considered unit for velocity is a meter per second.
As given in the problem Saturn is 890,700,000 miles from the Sun
1 mile = 1.61 x 10³ meters
890,700,000 miles = 890,700,000×1.61×10³ meters
=1.434×10¹² metes
As given If the speed of light is 3.0 x 10⁸ meters/second
Time = distance /speed
= 1.434×10¹² metes / 3.0 x 10⁸ meters/second
= 4780 seconds
Thus, the distance in the scientific notation would be 1.434×10¹² metes and it would take 4780 seconds for light from the Sun to reach Saturn.
Learn more about Velocity from here,
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A cheetah is running at a speed of 19.5 m/s in a direction of 69° north of west. Find the cheetahs velocity component due north and due west.
Answer:
The cheetahs velocity component due north is 6.99 m/s
The cheetahs velocity component due west is 18.21 m/s
Explanation:
Given;
speed of the cheetah, v = 19.5 m/s
direction of the cheetah's speed, θ = 69°
Find the attached document for explanation
The observation of a "wet spot" on a hot highway in the summer is caused by:_________.
a. dispersion
b. diffraction
c. refraction
d. reflection.
Answer: Refraction
Explanation:
The observation of a wet spot on a hot highway in the summer season is caused by refraction. Therefore, option (C) is correct.
What is refraction?Refraction can be defined as the redirection of light as it passes from one medium to another medium. The redirection of light is caused by a change in the medium or by the wave's change in speed.
Refraction of light can be described as an observed phenomenon, but other waves such as sound waves and water waves also experience refraction.
Refraction of light obeys Snell's law that the ratio of the sines of the angle of incidence and refraction must be equal to the ratio of phase velocities in the two media to the refractive index of the two media.
When the sunlight makes a blacktop hot highway. The appearance of the wet spot is bright because of the refraction of light from the sky.
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What is a main difference between a mixture and a pure substance?
O A mixture is only a liquid, but a pure substance can be in any state.
A mixture looks the same throughout, but a pure substance does not.
A mixture can vary in composition, but a pure substance has a set composition.
A mixture can be made up of a single compound, but a pure substance cannot.
оо
Answer:
C- A mixture can vary in composition, but a pure substance has a set composition
Explanation:
The main difference between a mixture and a pure substance is: A mixture can vary in composition, but a pure substance has a set composition ( option c )
MixtureA mixture is a substance which contains two or more constituents which can easily be separated by a physical means. It consists of two or more different substances, not chemically joined together.
SubstanceA pure substance consists only of one element or one compound.
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An object is thrown upward at an angle θ above the ground, eventually returning to earth. (a) Is there any place along the trajectory where the velocity and acceleration are perpendicular? If so, where? at the initial position of motion at the highest point in the trajectory at the final position of motion velocity and acceleration are never perpendicular
Answer:
Yes, at the highest point in the trajectory velocity and acceleration are perpendicular.
Explanation:
Let [tex]x-[/tex]axis be the ground and [tex]y-[/tex]axis is the height above the ground. Let the initial velocity of the object is [tex]u[/tex] having angle [tex]\theta[/tex] with respect to ground and the acceleration due to gravity , [tex]g[/tex], is acting in vertically downward direction as shown in figure.
As gravitational force is acting in vertical direction, so, it will not change the horizontal velocity of the object. So, at any instant throughout the projectile motion the [tex]x-[/tex]component of the initial velocity will remailns constant, i.e. [tex]u_x=u \cos \theta[/tex].
While, due gravitational force, [tex]y-[/tex]component of the initial velocity will change. Initially, [tex]u_y=u \sin \theta[/tex] is in vertically upward direction and gravitational force is actiongn vertically downward direction, so, at first [tex]u_y[/tex] will decrease untill it reaches the highest point of the trajectory as shown. At the highest point the vertical component of the velocity [tex]u_y=0[/tex], so, there is only horizontal component of the velocity. i.e [tex]u_x= u \cos\theta[/tex] .
Now, the resultant velocity of the object at the highest point is [tex]u \cos \theta[/tex] which is in the horizontal direction while the acceleration , [tex]g[/tex] , (due to gravily) is actiog in vertically downward direction.
Hence, at the highest point in the trajectory velocity and acceleration are perpendicular.
Somewhere at the greatest point of the trajectory, vector quantities become perpendicular. Considering gravity constantly pushes downward, a projectile's acceleration would always be downward.Furthermore, because the vertical velocity of something like a projectile approaches zero at the height of its trajectory, the first and only portion of the velocity which thus might not be zero seems to be the horizontal factor.
Thus the response above is appropriate.
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1. You are driving to the grocery store at 20 m/s. You are 110 m from an intersection when the traffic light turns red. Assume that your reaction time is negligible and that your car brakes with constant acceleration. What magnitude braking acceleration will bring you to a stop exactly at the intersection?
Answer:
-1.82m/s²
Explanation:
Given that the reaction time (t) is negligible and car brakes with constant acceleration.
Initial Velocity (u) = 20m/s
Distance(d) from Intersection when light turns red = 110m
Hence, the magnitude of braking acceleration that will bring the car to rest at exactly the intersection :
Using the motion equation:
v² = u² + 2as
Where v = final velocity at the intersection
u = initial velocity ; s = distance to intersection ; a = acceleration of the car
Exactly at the intersection ; v = 0
0 = 20² + 2×a×110
0 = 400 + 220a
-400= 220a
a = - 400 / 220
a = - 1.818
a = - 1.82 m/s²
- stands for negative acceleration (deceleration)
The deep scattering layer (DSL):_________
a) was discovered by Charles Darwin
b) is only seen at night
c) is a biological phenomenon that can be detected with sonar
d) is not a biological phenomenon
e) is a chemical boundary in the water
Answer:
C
Explanation:
Because its a region of high biological productivity with a lot of water organism allowing for high reflectivity of sonar pulse mimicking ocean bottom
What three forms of energy are represented when a match is lit?
Answer:
Three forms of energy when a match is being lit are potential, kinetic and thermal.
hope this helps! :)
Explanation:
Answer:
Potential Energy
Kinetic Energy
Thermal Energy
Explanation:
Could someone tell me if this is right or give me the answers so i can re write them! That would be so helpful:)
Answer:
Those are all right
Explanation:
Answer:
They are right! Nice job!
Explanation:
What is applied force?
Answer:
An applied force is a force that is applied to an object by a person or another object. If a person is pushing a desk across the room, then there is an applied force acting upon the object.
Explanation:
Calculate the magnitude and direction of the electric field (in N/C) 2.2 m from a long wire that is charged uniformly at λ = 3.6 ✕ 10−6 C/m. (Assume the wire goes through the origin and the point in question is located on the +z-axis. Express your answer in vector form.).
Answer:
29.5*10^3 k N/C
Explanation:
Using
E = λ/2πEor x k
So = 18*10^9 x 3.6 ✕ 10−6 / 2.2 x k
= 29.5*10^3 k N/C
The pacefic ocean has a surface area of about 166 241 700km^2 and an average depth of 3940 m. Estimate the volume of the Pacific ocean in cubic centimetres
Answer:
[tex] \lim_{(x,y) \to \(0,0)} \frac{2x {y}^{2} }{ {x}^{2} {y}^{2} } [/tex]
Explanation:
[tex]\lim_{(x,y) \to \(0,0)}[/tex]
if a car is traveling with a velocity of 20 m/s, how long will it take to reach 4000m
if 1 foot is 30.28 centimeters.how many cm is 130 feet
Answer:3,936.4
Explanation:
If 1 foot is 30.28 centimeters multiply 30.28 by 130
position (m)
80!
В
с
60
40
20
A
- 20
-40
10
20
30
40
50
time (sec)
Answer:
hola bb como estas dime bb en que te ayudo
Explanation:
A car traveling with an initial velocity of 10 m/s accelerates at a constant rate of 2.2 m/s^2 for 2 seconds. What distance does the car travel during this process
2.5 better than the first one more game to go hard but I 46 the bucks
Answer:
hsiahdjjsdhishshdakyeacs4y9yssig
Explanation:
ntesgs7thsjv6wlubx4euc
electricity is one kind of
Answer:
I think electricity is one kind of energy
Which of the following is one way creativity can help scientists? (20 points) +Brainiest
a
By ensuring they follow the scientific method
b
By increasing the amount of time it takes to complete scientific experiments
c
By making sure they only try things that have already been proven
d
By leading them to ask more questions about the natural world
A web page designer creates an animation in which a dot on a computer screen has a position of r⃗ =[ 4.50 cm +( 2.90 cm/s2 )t2]i^+( 4.70 cm/s )tj^ . Part A Find the average velocity of the dot between t=0 and t=2.0s. Give your answer as a pair of components separated by a comma. For example, if you think the x component is 3 and the y component is 4, then you should enter 3,4.
Answer:
V = (5.8cm/s)i, (4.7cm/s)j
Explanation:
Given :
r⃗ =[ 4.50 cm +( 2.90 cm/s2 )t2]i^+( 4.70 cm/s )tj^
To obtain the average velocity (V)
V = (r2 - r1) / (t2 - t1)
To obtain r1 and r2, substitute t1 = 0 and t2 = 2 respectively in the equation above
r1 = [ 4.50 cm +( 2.90 cm/s2 ) 0]i^+( 4.70 cm/s )0 j
r1 = 4.50 cm + 0 + 0 = (4.50cm)i + 0j
r2 = [ 4.50 cm +( 2.90 cm/s2 )2²]i^+( 4.70 cm/s )2 j
r2 = 4.50cm + (2.90 × 4)i + (4.70 × 2)j
r2 = (16.1cm)i + (9.4cm)j
V = [(16.1 - 4.50)i - (9.4 - 0)j] / 2 - 0
V = 11.6i / 2 ; 9.4j / 2
V = (5.8cm/s)i, (4.7cm/s)j
Julie, a third-grade student, believes that the moon disappears on certain days every month. Explain why the following information is or is not scientific evidence which can be used to evaluate Julie’s hypothesis.
The highest speed attained by a cyclist on level ground is 105 km/h. To attain this speed, the cyclist used a streamlined recumbent bike. Starting from rest, he gradually built up his speed by pedaling furiously over a distance of 3.2 km. If his acceleration was uniform over this distance, what was the acceleration and how long did the cyclist take to build up his final speed
Answer:
The acceleration is 0.133 m/s²
The time taken to build the final speed is 219.32 s
Explanation:
Given;
final speed of the cyclist, v = 105 km/h = 29.17 m/s²
distance traveled by the cyclist, d = 3.2 km = 3,200 m
initial speed, u = 0
Apply the following kinematic equation to determine the acceleration of the cyclist;
v² = u² + 2as
(29.17 )² = 0 + (2 x 3200)a
850.89 = 6400a
a = (850.89 ) / (6400)
a = 0.133 m/s²
The time taken to build up the final speed is given by;
v = u + at
29.17 = 0 + (0.133)t
t = 29.17 / 0.133
t = 219.32 s
