Which statement describes a question that can guide the design of a
scientific investigation?
A. It asks about a cause-and-effect relationship between two
variables.
B. It asks about how the observations will be organized,
C. It asks about whether a controlled variable is necessary.
D. It asks about the preferred outcome of the investigation.
Answer:
The correct answer is:
It asks about a cause-and-effect relationship between two variables (A)
Explanation:
Scientific investigations are aimed as developing a hypothesis and proving the validity or not of the hypothesis developed. In order for these hypotheses to be tested, experiments must be done, and the experiments are designed based on the identification of a cause-and-effect relationship existing between two variables to be tested, where the "cause" is varied to various degrees and the "effect" of the variation is recorded. Therefore, knowing the cause-and-effect relationship will guide the experimental design, which will be aimed at manipulating the causes to see how these manipulations affect the second variable.
Answer:
A
Explanation:
How does the energy in matter affect the state?
Answer:
Because of melting and freezing a higher heat will make something a plasma or liquid by melting it. by freezing you can make a liquid or gas solid.
Explanation:
Air that initially occupies 0.22 m3 at a gauge pressure of 86 kPa is expanded isothermally to a pressure of 101.3 kPa and then cooled at constant pressure until it reaches its initial volume. Compute the work done by the air. (Gauge pressure is the difference between the actual pressure and atmospheric pressure.)
Answer:
total work done = -5960.8 J
Explanation:
given data
initial volume v1 = 0.22 m³
initial pressure p1 = 86 kPa
final pressue p2 = 101.3 kPa
solution
we apply here isothermal expansion that is express as
p1 × v1 = p2 × v2 ......................1
put here value
86 × 0.22 = 101.3 × v2
v2 = 0.1867 m³
and
work done will be here
w1 = p1 × v1 × ln([tex]\frac{p1}{p2}[/tex]) ....................2
w1 = 86 × 10³ × 0.22 × [tex]ln(\frac{86}{101.3})[/tex]
w1 = -3.097 × 10³ J
and
it is cooled to initial volume at constant pressure so here work done will be
w2 = p(v2 - v1) .................3
w2 = 86 × 10³ × ( 0.1867 - 0.22 )
w2 = -2863.8 J
so
total work done is
total work done = w1 + w2
total work done = -3097 + -2863.8
total work done = -5960.8 J
Add these two velocity vectors to find the magnitude of their resultant vector. A. 4.6 meters/second B. 0.8 meters/second C. 2.2 meters/second D. 7.0 meters/second
The magnitude of the resultant vector is D, 7.0 meters/second, and the direction is to the left.
How to find magnitude?To add these two velocity vectors, find the magnitude and direction of each vector. The magnitude of the first vector is 5.8 meters/second, and the direction is to the right. The magnitude of the second vector is 1.2 meters/second, and the direction is to the left.
To find the magnitude of the resultant vector, add the magnitudes of the two vectors. The magnitude of the resultant vector is 5.8 meters/second + 1.2 meters/second = 7.0 meters/second.
To find the direction of the resultant vector, find the angle between the two vectors. The angle between the two vectors is 180 degrees. The direction of the resultant vector is 180 degrees from the first vector, which is to the left.
Therefore, the magnitude of the resultant vector is 7.0 meters/second, and the direction is to the left.
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Compare How does
the horse's average speed
from 60 s to 120 s compare
to its average speed from
120 s to 180 s?
Answer:
3.75 m/s
Explanation:
Formula:
Average Speed = Total Distance / Total Time
Given:
Total Distance = 150 m
Total Time = 160 - 120 = 40 s
To Find:
Average Speed
Solution:
Average Speed = 150/40
Average Speed = 3.75 m/s
How fast does the moon rotate around the Earth?
The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis. As a result, the moon does not seem to be spinning but appears to observers from Earth to be keeping almost perfectly still.
Answer:
approximately 27 days
The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis.
Explanation:
Select the correct answer. As per the new modified method of classifying the magnitude of stars, what kind of values were the brightest stars assigned? A. negative values B. positive values C. fractional values D. letters
Answer:
A. Negative values
Explanation:
Answer:
A-negative values
Explanation:
As per the new modified method of classifying the magnitude of stars, what kind of values were the brightest stars assigned?
A.
negative values
B.
positive values
C.
fractional values
D.
letters
An airplane with a hot-wire anemometer mounted on its wing tip is to fly through the turbulent boundary layer of the atmosphere at a speed of 50 m/sec. The velocity fluctuations in the atmosphere are of order 0.5 m/sec, the length scale of the large eddies is about 100 m. The hot-wire anemometer is to be designed so that it will register the motion of the smallest eddies.What is the highest frequency the anemometer will encounter
Answer:
0.55 hz
Explanation:
Given that the plane fly through the turbulent boundary layer of the atmosphere at a speed of 50 m/sec. And the velocity fluctuations in the atmosphere are of order 0.5 m/sec, the length scale of the large eddies is about 100 m.
The maximum speed attained will be
Maximum speed = 50 + 0.5 = 5.5 m/s
The Length = 100m
Speed = FL
Where F = frequency
Substitute speed and distance length into the formula
55 = 100F
F = 55/100
F = 0.55 Hz
Therefore, the highest frequency the anemometer will encounter will be 0.55 Hz
Answer:
40079 Hz
Explanation:
1. The first step is to calculate energy dissipation ∈=u^3/l and here u is fluctuating velocity
∈=(0.5^3)/100 = 0.00125 m^2/s^3
2. Find out the length scale of the small eddies
η=(viscosity/∈)^1/4
η=(1.470e-5/0.00125)^1/4 = 0.00126 m
3. The frequency associated with these small-scale eddies will be the greatest frequency the anemometer will encounter, thus:
u_max=f_max * η
u_max = u + u' = 50+0.5=50.5 m/s
f_max = u_max/η = 50.5/0.00126 = 40079 Hz
This is the heighest frequency the anemometer will encounter.
1. What does the horizontal axis ordinarily oscilloscope? The vertical measure on an axis?
2. What frequency should the function generator be set to if period of 25 us is a desired?
Answer:
vertical axis measures voltage while
The horizontal axis of an oscilloscope measures time
2) we are told that Period
T = 25 microseconds = 25*10^-6 s
So we also know that
frequency f = 1/T
So
= 1/(25*10^-6)
= 40,000 Hz
A ball rolls off a 1.0 m high table and lands on the floor 3.0 m away from the table. a. How long is the ball in the air?
Answer:
The ball is in the air for approximately 0.45 seconds
Explanation:
We only need to use the information on the height of the table to find the time, since the vertical movement is a movement under the acceleration of gravity, and with no initial velocity in the y-direction (recall that the ball rolls off a 1.0 m high table)
therefore the equation of motion for the vertical component is:
[tex]y_f-y_i=\frac{1}{2}\, g\,t^2[/tex]
which for our information becomes:
[tex]y_f-y_i=\frac{1}{2}\, g\,t^2\\1 = 4.9\,t^2\\t^2=\frac{1}{4.9} \\t=\sqrt{\frac{1}{4.9}} \\t\approx 0.45\,s[/tex]
A cheetah accelerates from rest at a rate of 9 m/s^2 for 3s. How far does it travel in this time? Assume the cheetah moves in a
straight line.
a) 27.0 m
b) 40.5 m
c) 13.5 m
d) 54.0 m
Answer:
b) 40.5 m
Explanation:
Given:
v₀ = 0 m/s
a = 9 m/s²
t = 3 s
Find: Δx
Δx = v₀ t + ½ at²
Δx = (0 m/s) (3 s) + ½ (9 m/s²) (3 s)²
Δx = 40.5 m
The mere exposure effect is
A car moves from rest with an acceleration of 0.2ms
Find its velocity when it has moved a
distance of 50m
From the problem we notice that the question
does not involver. Therefore, the required equation
is)
Explanation:
Given:
Δx = 50 m
v₀ = 0 m/s
a = 0.2 m/s²
Find: v
The problem does not involve time. Therefore, the required equation is:
v² = v₀² + 2aΔx
Plug in values and solve:
v² = (0 m/s)² + 2 (0.2 m/s²) (50 m)
v = 4.47 m/s
The velocity of the car when it has moved a distance of 50 meters is approximately 4.47 m/s.
To find the velocity of the car when it has moved a distance of 50 meters, we can use the following equation of motion:
v² = u² + 2as
Where:
v = final velocity
u = initial velocity (which is 0 in this case as the car starts from rest)
a = acceleration
s = distance traveled
Plugging in the values into the equation:
v² = 0² + 2(0.2)(50)
v² = 0 + 20
v² = 20
Taking the square root of both sides:
v = √20
v = 4.47 m/s
Therefore, the velocity of the car when it has moved a distance of 50 meters is approximately 4.47 m/s.
To know more about the velocity:
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An undiscovered planet, many lightyears from Earth, has one moon in a periodic orbit. This moon takes 17601760 × 103 seconds (about 2.0×1012.0×101 days) on average to complete one nearly circular revolution around the unnamed planet. If the distance from the center of the moon to the surface of the planet is 295.0295.0 × 106 m and the planet has a radius of 3.603.60 × 106 m, calculate the moon's radial acceleration acac .
Answer:
The value is [tex]a_r = 3.81 *10^{-3} m/s^2[/tex]
Explanation:
Generally the moon's radial acceleration is mathematically represented as
[tex]a_r = r * w^2[/tex]
Here [tex]w[/tex] is the angular velocity which is mathematically represented as
[tex]w =\frac{2 \pi }{ T}[/tex]
substituting [tex]1760 * 10^3 \ seconds[/tex] for T(i.e the period of the moon ) we have
[tex]w =\frac{2 * 3.142 }{ 1760 * 10^3}[/tex]
=> [tex]w = 3.57 *10^{-6} \ rad/s [/tex]
From the question r(which is the radius of the orbit ) is evaluated as
[tex]r = R + H[/tex]
substitute [tex]3.60 * 10^6 m[/tex] for R and [tex]295.0 * 10^6 \ m[/tex] H
[tex]r = 295.0 * 10^6 +3.60 * 10^6[/tex]
=> [tex]r = 2.986 *10^{8} \ m [/tex]
So
[tex]a_r = 2.986 *10^{8} * ( 3.57 *10^{-6} )^2[/tex]
[tex]a_r = 3.81 *10^{-3} m/s^2[/tex]
it is required that an object weighing 8N be moved up ward at an acceleration of 2m/s what is the upward force needed
Answer:
F = 1.6 N
Explanation:
Newton's Second Law of Motion states that whenever an unbalanced force is applied on a body. It produces an acceleration in the body, in its own direction. The magnitude of the force is given by the following formula:
F = ma
where,
F = Force Required to Move the Object Upward = ?
m = mass of object
a = upward acceleration = 2 m/s²
but, we know that weight of object is given as:
Weight = mg
8 N = m(9.8 m/s²)
m = 0.8 kg
using values in the equation:
F = (0.8 kg)(2 m/s²)
F = 1.6 N
Write the following numbers in proper scientific notation:
1.) 36513
2.) 0.00050
3.) 8004
4.) 0.00000000406
Answer:
0.00050, 0.000000000406, 36513
A girl delivering newspapers covers her route by traveling 6.00 blocks west, 3.00 blocks north, and then 7.00 blocks east. HINT (a) What is her final position relative to her starting location? (Enter the magnitude in blocks and the direction in degrees north of east.) magnitude blocks direction ° north of east (b) What is the length (in blocks) of the path she walked?
Answer:
a) we can form a triangle in order to use the Pythagorean theorem = 3² + 1² = h²
h² = 9 + 1 = 10
h = √10
h = 3.1623 blocks
we must also find the angle at the initial point of the triangle (A):
tan⁻¹ (1/3) = 18.43°
the position relative to her starting position is 90° - 18.43° = 71.57° north of east
b) total distance traveled = 6 + 3 + 7 = 16 blocks
Which is the process by which a solid changes to a liquid? O condensation O evaporation O melting sublimation
Answer:
Melting
Explanation:
The process in which a solid changes to a liquid is called melting. This process is also termed as fusion. Due to application of heat and pressure, the internal energy of a solid increases and the molecules become far from each other due to which it starts to melt.
Hence, the correct option is (c) "melting".
Answer:
c. melting
Explanation:
took the quiz on edge
The position of a particle is r⃗ (t)=(3.0t2iˆ+5.0jˆ−6.0tkˆ)m. (a) Determine its velocity and acceleration as functions of time. (b) What are its velocity and acceleration at time t = 0?
Explanation:
It is given that,
The position of a particle is given by :
[tex]r(t)=(3t^2i+5j-6tk)\ m[/tex]
(a) Velocity of a particle is given by :
[tex]v=\dfrac{dr(t)}{dt}[/tex]
Putting values,
[tex]v=\dfrac{d}{dt}(3t^2+5-6t)\\\\v=(6ti-6k)\ m/s[/tex]
The acceleration of the particle is given by :
[tex]a=\dfrac{dv}{dt}\\\\a=\dfrac{d}{dt}(6t-6)\\\\a=6i\ m/s^2[/tex]
(b) At t = 0,
Velocity, v = 6k m/s
Acceleration, a = 6i m/s²
Do you think a hurricane can be considered to be a heat machine? Why?
Answer:
No
Explanation:
Hurricanes always do not bring heat. For example, Hurricane Sandy brought snow.
Is the following hypothesis scientific? Why? "Intelligent life exists on other planets
somewhere in the universe."
Answer:
yes
Explanation:
The hypothesis is scientific because there is no solid evidence to draw out the theory. Therefore the idea of other intelligence on other planets is scientific until found unworthy or scientifically proven wrong enough. Hope this helps a little:)
Translate the following sentence into an equation. "The distance traveled is the speed multiplied by the time." a) d = v * t a) d = v * t b) Δx = v * Δt c) v = d/t d) d=Δx*t
The correct answer is A) d = v * t
Explanation:
When writing an equation the goal is to represent the equality between different mathematical expressions or elements. Due to this, in an equation the symbol = is always used. Additionally, to translate a sentence into an equation, the variables should be represented using numbers or letters.
For example, in the sentence "The distance traveled is the speed multiplied by the time" there are three variables mentioned: distance, speed, and time. Also, these can be represented through the letters d (distance), v (speed or velocity), and t (time). Besides this, the sentence explains speed should be multiplied by time, which means it should be written as v × t or v * t and this is equivalent (=) to distance or t. According to this, the final equation would be d = v * t.
What is the ultimate source of energy for an ecosystem?
Answer:
Obviously the answer is Sun...
When students were surveyed about the kind of thinking they considered to be most important in their academic studies, the majority chose?
Answer:Critical Thinking
Explanation:
7.2 in college success text back
A car runs around a circular race track from the point A to diametrically opposite point B The radius of the circle is ‘r’ . The distance traveled by the car is ________ the displacement of the car is _________ show your work!
Answer:
Distance = πr
Displacement = 2r
Explanation:
First we need to find the distance covered by the car. As the car is travelling on a circular path and it traveled to a diametrically opposite point on the circular path. Therefore, the distance covered by the car must be the half value of the circumference.
Distance = Circumference/2
Distance = 2πr/2
Distance = πr
Since, displacement is the straight line distance between two points. So, the displacement in moving from a point to its diametrically opposite point must be equal to the diameter of circle:
Displacement = Diameter
Displacement = 2r
why Newtown made the laws of motion
Answer:Newton’s law also states that larger bodies with heavier masses exert more gravitational pull, which is why those who walked on the much smaller moon experienced a sense of weightlessness, as it had a smaller gravitational pull. To help explain his theories of gravity and motion, Newton helped create a new, specialized form of mathematics.
Explanation:
Answer:
Newton was convinced the planets must obey the same physical laws that are observed on Earth. This meant there must be an unseen force acting on them. He knew from experiment that, in the absence of an applied force, a moving body will continue in a straight line forever.
Explanation:
What are the benefits of evolution for the human population?
Answer:
I hope you fall down a 40 floor hotel resort onto the porch, and explode into the gushing body you are!
Explanation:
Kriste walks once around a large circle at a constant speed.
What is her average velocity for the whole walk in m/s?
Answer:
This question is incomplete
Explanation:
This question appears incomplete because of the absence of the value for the constant speed. However, there is a striking similarity between speed and velocity and the major difference between the two "quantities" is that speed is a scalar quantity while velocity is a vector quantity.
A scalar quantity (such as speed) is one that has a magnitude but no direction while a vector quantity (such as velocity) is one that has both magnitude and direction. Hence, velocity can be described as the speed in a particular direction (around a large circle as suggested in the question).
From the description above, it can be deduced that Kriste's average velocity is the same as her constant speed as she walks around the large circle.
NOTE: The unit for both speed and velocity here will be in m/s
Lizard: A lizard is running in a straight line according to the following: xx(tt) = tt3⁄3 − tt2 + tt He starts at tt = 0. (a) Determine vv(tt). (b) When is the lizard at rest? (c) When is the lizard moving in the positive xx direction? (d) When is the lizard moving in the negative xx direction? (e) When does the lizard have zero acceleration?
Answer:
Explanation:
a ) x ( t ) = t³ / 3 - t² + t
v = dx / dt = 3 t² / 3 - 2 t + 1 = t² - 2 t + 1
b ) lizard is at rest , v( t ) = 0
t² - 2 t + 1 = 0
( t - 1 )² = 0
t = 1
c )
velocity is positive when
t² - 2 t + 1 > 0
( t - 1 ) ² > 0
Here we see that LHS is a square so it is always positive whatever be the value of t
So velocity is always positive or lizard is always moving in positive x direction .
d ) It never moves in negative x direction .
e )
a ( t ) = dv / dt = 2t - 2
t = 1
so it has zero acceleration at t = 0 .
A car slowed down from 70 mils to 30 mi/s on the highway in 20
seconds. What was the car's acceleration?