Answer:
2.89 hours
Explanation:
given :
Vo = 72 km/h
Vt = 90 km/h
S = 234 km
find : the time taken (t) = ?
solution :
2.a.s = Vt² - Vo²
2.a.(234) = 90²- 72²
468.a = 8100 - 5184
= 2916
a = 2916/468 = 6.23 km/h²
so,
t = (Vt-Vo) /a
= (90-72)/ 6.23
= 18/ 6.23
= 2.89 hours
Juanita ran one mile around her school track in six minutes. What is
her average speed, and what is the magnitude of her average velocity?
10 mph, 0 mph
6 mph, 0 mph
6 mph, 6 mph
10 mph, 10 mph
Answer:
The correct option is a) 10 mph, 0 mph.
Explanation:
1. The average speed (S) is a magnitude given by:
[tex] S = \frac{D}{T} [/tex]
Where:
D: is the total distance = 1 mi
T: is the total time = 6 min
[tex] S = \frac{D}{T} = \frac{1 mi}{6 min}*\frac{60 min}{1 h} = 10 mph [/tex]
Hence, the average speed is 10 mph.
2. The average velocity is a vector:
[tex] V = \frac{\Delta d}{\Delta t} = \frac{d_{f} - d_{i}}{t_{f} - t_{i}} [/tex]
Where:
[tex]d_{f}[/tex]: is the final distance
[tex]d_{i}[/tex]: is the initial distance
[tex]t_{f}[/tex]: is the final time
[tex]t_{i}[/tex]: is the initial time
Since Juanita ran one mile around her school track, the final position is the same that the initial position, so the magnitude of the average velocity is zero.
Therefore, the correct option is a) 10 mph, 0 mph.
I hope it helps you!
To overcome the problems that blur images and don't provide the best resolution from Earth, astronomers have started using flexible mirrors that change shape many times each second. This technique is called:
Answer:
adaptive optics
Explanation:
simple
CLASS ENVIRONMENTAL SCIENCE
The____domain incorporates cultural norms that directly impact sustainable development. The___ domain focuses on the protection and preservation of natural and artificial resources
Blank 1: Blank 2:
A: social. A: public policy
B: economic. B: technological
C: sustainable. C: environmental
An inquisitive physics student and mountian climber climbs a 43.6 m cliff that overhangs a calm pool of water. He throws two stones vertically downward, 1.35 s apart and observes that they cause a single splash. The first stone has an initial velocity of 1.8 m/s. How long after release of the first stone do the two stones hit the water
Answer:
Explanation:
What we are basically looking for here is how long it takes the first stone to hit the water. We have everything we need to figure that out. We will use the equation
Δx = . Filling in, we will solve for t, the time is takes the first stone to hit the water (which is the same for both since they both hit the water at the same time):
which is a quadratic that we will have to factor. Get it into standard form, setting it equal to 0:
and factor to get that
t = 3.2 s and t = -2.8 s
Since time can't ever be negative, it takes 3.2 s for the stones to hit the water.
The amount of solar radiation received by Earth from the sun, known as _______________________, is greatest when the sun is directly overhead a location. (Answer must be correctly spelled and is case sensitive).
The amount of solar radiation received by Earth from the sun, known as insolation, is greatest when the sun is directly overhead a location.
The amount of solar radiation received by Earth from the sun is known as insolation, solar insolation is greatest when the sun is directly overhead a location.
What is solar energy?The energy transferred from the Sun in the form of electromagnetic radiation is known as the solar energy
It can be used as thermal energy for various life purposes as well as for electricity conversion with the help of solar photovoltaic cells
The ratio of total electrical energy generated by a solar photovoltaic panel to its total thermal energy is known as solar energy efficiency. The solar panel's area and design have an impact on how energy-efficient it is.
Thus, the term "insolation" refers to the amount of solar radiation that Earth receives from the sun. Solar insolation is highest when the sun is directly overhead a location.
Learn more about solar energy from here, refer to the link;
brainly.com/question/9704099
#SPJ2
A 4 LBfweight is attached to a spring suspended from the ceiling. When the weight comes to rest at equilibrium, the spring has been stretched 3 inches. The damping constant for the system is 2 LBf−sec ft . If the weight is raised 9 inches above equilibrium and given an initial upward velocity of 2 ft/sec, determine the equation of motion of the weight and give its damping factor, quasiperiod and quasifrequency.
Answer:
attached below
Explanation:
The initial conditions :
x(0) = - 9 inches = -3/4 ft
x'(0) = - 2 ft/sec
spring stretched 3 inches = 1/4 ft
mass = w / g = 4 Ib / 32 ft/sec^2 = 1/8 slug
the spring constant ( k ) = w / l = 4 / ( 1/4 ) = 16 Ib/ft
applying the second law of motion
m d^2x/dt^2 + b dx/dt + kx
= 1/8 d^2x/dt^2 + 2 dx/dt + 16 x
= d^2x/dt^2 + 16 dx/dt + 128 x ------- ( 1 )
we will resolve the above equation to obtain the required equation of motion x( t )
Attached below is the remaining part of the solution
6. An object is fired from the gound at 275 m/s at an angle of 55° N of E.
a. How far away did the object first hit the ground?
b. what is the maximum height that the object reaches?
there u go fella hope u understood
With what tension must a rope with length 3.00 mm and mass 0.105 kgkg be stretched for transverse waves of frequency 40.0 HzHz to have a wavelength of 0.790 mm
Answer:
the tension of the rope is 34.95 N
Explanation:
Given;
length of the rope, L = 3 m
mass of the rope, m = 0.105 kg
frequency of the wave, f = 40 Hz
wavelength of the wave, λ = 0.79 m
Let the tension of the rope = T
The speed of the wave is given as;
[tex]v = f\lambda = \sqrt{\frac{T}{\mu} } \\\\where;\\\\\mu \ is \ mass \ per \ unit \ length\\\\\mu = \frac{0.105}{3} = 0.035 \ kg/m\\\\v = f\lambda = 40 \times 0.79 = 31.6 \ m/s\\\\v = \sqrt{\frac{T}{\mu} } \\\\v^2 = \frac{T}{\mu} \\\\T = v^2 \mu\\\\T = (31.6^2)(0.035)\\\\T = 34.95 \ N[/tex]
Therefore, the tension of the rope is 34.95 N
The 75.0 kg hero of a movie is pulled upward at a constant velocity by a rope. What is the tension on the rope?
Answer:
750 N
Explanation:
the tension on the rope is the weight of the hero
A box has a mass of 4kg and surface area 4m². Calculate the
pressure exerted by the box on the floor.
Answer:
10 pa
Explanation:
4kg* 10 (or 9.8m/s2) = 40
40N /4m2 =10
The most powerful empire between the 1500s and 1600s was the __________ Empire.
A.
Ottoman
B.
Mauryan
C.
Roman
D.
Persian
Answer:
A
Explanation:
Answer:
Ottoman
Explanation:
siri told me after I asked
Calculate surface tension of an enlarged radius of 4cm to 6cm and amount of work necessary for enlargement was 1.5×10^-4 joules
Answer:
[tex]T=7.5*10^{-5}[/tex]
Explanation:
From the question we are told that:
Radius [tex]r=2cm[/tex]
Work done [tex]W=1.5×10^-4 joules[/tex]
Generally the equation for Work done is mathematically given by
[tex]W=T.dA[/tex]
Therefore
[tex]T=\frac{W}{dr}[/tex]
[tex]T=\frac{1.5*10^{-4}}{2}[/tex]
[tex]T=7.5*10^{-5}[/tex]
A cup of mass 0.4 kg with its base radius of 4 cm is kept on a table. Calculate the pressure exerted by the cup on the table.
Answer:
779.87 N/m²
Explanation:
Pressure = Force (F) / Area (A)
Recall :
Force = ma ; mass * acceleration due to gravity
a = 9.8 m/s² ; mass = 0.4kg
Force, F = 0.4 * 9.8 = 3.92 N
Area = πr² ; r = Radius = 4cm = 4 / 100 = 0.04 m
Area = π0.04² = 0.0050265 m²
Hence,
Pressure = 3.92 / 0.0050265
Pressure = 779.86670 N/m²
Pressure = 779.87 N/m²
How long will it take a car to acceleration from 15.2ms to 23.Ms if the car has an average acceleration of 3.2m\s
Answer: 2.43 s
Explanation:
Initial velocity is [tex]u=15.2\ m/s[/tex]
Final velocity [tex]v=23\ m/s[/tex]
Average acceleration is [tex]a_{avg}=3.2\ m/s[/tex]
Average acceleration is change in velocity in the given amount of time
[tex]\therefore a_{avg}=\dfrac{v-u}{t}\\\\\Rightarrow 3.2=\dfrac{23-15.2}{t}\\\\\Rightarrow t=\dfrac{7.8}{3.2}\\\\\Rightarrow t=2.43\ s[/tex]
Thus, 2.43 s is required to acquire that average acceleration with 23 m/s velocity .
Give reason:
Mass and volume are called physical quantities.
a.
b
Ionath is called
Mass and volume are called physical quantities because they can be measured by using physical devices i.e. mass is measured by using beam balance and volume is measured by using metre scale .
convert the following quantities
[tex]25m {}^{2} \: into \: cm {}^{2} [/tex]
Answer:
[tex] \rm 250000 \; cm^2 [/tex]
Explanation:
Refer to the attachment.
[tex]what \: is \: mirror \: {?}[/tex]
A 90 kg astronaut Travis is stranded in space at a point 12 m from his spaceship. In order to get back to his ship, Travis throws a 0.50 kg piece of equipment so that it moves at a speed of 4 m/ s directly away from the spaceship towards the left . How long will it take him to reach the ship? *hint find his speed after the collision and consider it a constant speed all the way back to his spaceship*
Answer:
Explanation:
This is a recoil problem, which is just another application of the Law of Momentum Conservation. The equation for us is:
[tex][m_av_a+m_ev_e]_b=[m_av_a+m_ev_e]_a[/tex] which, in words, is
The momentum of the astronaut plus the momentum of the piece of equipment before the equipment is thrown has to be equal to the momentum of all that same stuff after the equipment is thrown. Filling in:
[tex][(90.0)(0)+(.50)(0)]_b=[(90.0)(v)+(.50)(-4.0)]_a[/tex]
Obviously, on the left side of the equation, nothing is moving so the whole left side equals 0. Doing the math on the right and paying specific attention to the sig fig's here (notice, I added a 0 after the 4 in the velocity value so our sig fig's are 2 instead of just 1. 1 is useless in most applications).
0 = 90.0v - 2.0 and
2.0 = 90.0v so
v = .022 m/s This is the rate at which he is moving TOWARDS the ship (negative was moving away from the ship, as indicated by the - in the problem). Now we can use the d = rt equation to find out how long this process will take him if he wants to reach his ship before he dies.
12 = .022t and
t = 550 seconds, which is the same thing as 9.2 minutes
A battery of emf 5V and internal resistance 2ohm is joined to a resistor of 8ohm.Calculate the terminal potential difference.
Answer:
4V
Explanation:
First, we calculate the total resistance to the given battery cell of emf 5V. The total resistance is the sum of all the resistance in the cell i.e.
Total resistance = 2Ω + 8Ω = 10Ω
Using ohms law equation to calculate the current passing through the battery cell:
V = IR
Where; V = voltage, I = current, R = resistance
5V = I × 10Ω
I = 5/10
I = 0.5A
Terminal voltage is calculated by the us of the following equation:
V=emf−IR
Where; R is internal resistance
V = 5 - (0.5 × 2)
V = 5 - 1
V = 4V
Therefore, the potential difference across the terminals of the battery cell is 4V
What is meant by magnetic field
Answer:
a. Magnetic field is a location of a vector field around an electric current or magnet formed due to moving electric charges, or magnetic material and has a magnetic effect and exerts a force on other magnetic materials, electric current, and electric charges. The Earth's magnetic field that has the effect of turning a compass needle is an example of a magnetic field
b. The number of turns of the coil, N, in Diagram 1.1 > The number of turns of the coil, N, in Diagram 1.2
The pattern of the iron filings in Diagram 1.1 are closer with less space in between than the pattern of iron filings in Diagram 1.2
The angle of deflection of the ammeter pointer in Diagram 1.1 will be > The angle of deflection of the ammeter pointer in Diagram 1.2, given that the number of turns and current are inversely proportional
c. i. The pattern of the iron filings will have rings which are more closely arranged to each other as the strength of the magnetic field is increased
ii. As the number of turns is increased, the magnetic field is increased
Explanation:
what is measurement?
Which statement or question is a good hypothesis
5- Clasifica los siguientes cambios de la materia, anotando delante de cada uno cambio físico (F) o cambio químico (Q): • Disolver azúcar en agua • Freir una chuleta • Arrugar un papel • El proceso de la digestión • Secar la ropa al sol • Congelar una paleta de agua • Hacer un avión de papel • Oxidación del cobre • Romper un lápiz • Prender fuegos artificiales • Excavar un hoyo • Quemar basura
Answer:
1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.
2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.
3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.
4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.
5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.
6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.
7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.
8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.
9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.
10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.
11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.
12) Quemar basura - Cambio químico - Reacción de combustión.
Explanation:
A continuación, veremos que representa cada caso:
1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.
2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.
3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.
4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.
5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.
6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.
7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.
8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.
9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.
10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.
11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.
12) Quemar basura - Cambio químico - Reacción de combustión.
In the hydraulic system depicted, the cylinder on the left has a diameter of 2 inches and the cylinder on the right has a diameter of 6 inches. If 100 lbs of force was applied to the cylinder on the left, what force would be exerted on the cylinder on the right
Answer:
F2 = 900 lbs
Explanation:
From pascal principle;
F1/A1 = F2/A2
Force on cylinder at left; F1 = 100 lbs
Diameter of cylinder at left; d1 = 2 inches
Diameter of cylinder at right; d2 = 6 inches
Formula for area of top of cylinder = πr²
Thus;
Area of top of left cylinder; A = π × 2² = 4π
Area of top of right cylinder; A = π × 6² = 36π
Thus;
100/4π = F2/36π
F2 = (36π × 100)/4π
F2 = 900 lbs
The force that the left team pulls with is 1000 N. If the right team's total mass is 300 kg and they accelerate by 1.2 m/s2, what is the force of resistance on the right team
Answer:
the force of resistance on the right team is 360 N
Explanation:
Given;
force of the left team, = 1000 N
total mass of the right team, m = 300 kg
acceleration of the right team, a = 1.2 m/s²
The force of resistance of the right team is calculated as;
Force = mass x acceleration
Force, F = 300 x 1.2
Force = 360 N
Therefore, the force of resistance on the right team is 360 N
After landing the aeroplane's momentum becomes zero. Explain how
the law of conservation holds here.
Answer:
The law of momentum conservation can be stated as follows. For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.
Question 23 of 23
Suppose a current flows through a copper wire. Which two things occur?
O A. The field is parallel to the direction of flow of the current.
B. An electric field forms around the wire.
OC. A magnetic field forms around the wire.
U
D. The field is perpendicular to the direction of flow of the current.
SUBM
Answer:
The field is parallel to the direction of flow of the current.
While traveling north on an expressway, a car traveling 60 mph (miles per hour) slows down to 30 mph in 12 minutes due to traffic conditions
Answer:
acceleration = - 150 m/s^2
distance = 9 miles.
Explanation:
initial speed, u = 60 mph
time, t = 12minutes = 0.2 hour
final speed, v = 30 mph
Let the acceleration is a and the distance is s.
By the first equation of motion
v = u + at
30 = 60 + a x 0.2
a = - 150 m/s^2
Let the distance is s.
Use third equation of motion is
[tex]v^2 = u^2 + 2 a s \\\\30^2 = 60^2 + 2 \times 150\times s\\\\s = 9 miles[/tex]
When the E string of a guitar (frequency 330 Hz) is plucked, the sound intensity decreases by a factor of 2 after 4 s. Determine
Answer:
[tex]Q=50.3[/tex]
Explanation:
From the question we are told that:
Frequency [tex]F=330Hz[/tex]
Sound intensity drop [tex]I_d=2[/tex]
Time [tex]T=4s[/tex]
Therefore
Sound intensity Ratio
[tex]\frac{I}{I_x}=\frac{1}{2}[/tex]
Generally the equation for Sound intensity is mathematically given by
[tex]\frac{I}{I_x}=e^{-4\ \=t}[/tex]
[tex]\frac{1}{2}=e^{-4\ \=t}[/tex]
[tex]\=t =5.8s[/tex]
Generally the equation for Quality Factor is mathematically given by
[tex]Q=2 \pi\frac{E}{\triangle E}[/tex]
[tex]Q=2 \pi\frac{E}{\frac{E}{2*4}}[/tex]
[tex]Q=50.3[/tex]
What is the dependent variable in this
experiment?
DONE
Biologists designed an experiment to test
the effect of compost on the development
of root crops. They tested several different
crops, including carrots, potatoes, beets,
and onions. They grew most of the plants
in the greenhouse, but due to space issues,
they had to grow some outdoors. They gave
all the plants the same amount of compost.
They obtained the compost from a local
farmer and from the local hardware store.
They ran out of the farmer's compost, so
some of the plants received that compost
when the seeds were planted and other
plants got hardware store compost after
the plants had already started growing.
What is the independent variable in this
experiment?
DONE
Answer:
"the plants had already started growing."
Explanation:
I think this is the answer because the definition of a dependent variable is the variable that is being affected by the change. Since the plants had already started growing BECAUSE of "They ran out of the farmer's compost, so
some of the plants received that compost
when the seeds were planted and other
plants got hardware store compost after
the plants had already started growing."
Sorry if I am wrong, I am just a 4th grader, pls don't hate on me, I am just trying to help :)
Answer:
It's compost
Explanation:
In case you needed the dependent variable, its the amount of plant growth
