Answer:
1. 45 m
2. 50 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 20 m/s
Time (t) = 3 s
1. Determination of the position (i.e height)
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
h = ½gt²
h = ½ × 10 × 3²
h = 5 × 9
h = 45 m
2. Determination of the velocity.
Initial velocity (u) = 20 m/s
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Velocity (v) =?
v = u + gt
v = 20 + (10 × 3)
v = 20 + 30
v = 50 m/s
what is a weed (question answer)
Answer:
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place". Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks
Why would researchers not be allowed to recreate the Little Albert experiment today?
Answer:
Explanation:
En la historia de la ciencia se han dado auténticas barbaridades. Pruebas con animales que hoy no perdonaría nadie, o investigaciones de conducta con personas como la de la cárcel de Stanford, que se han saldado como una especie de pasado incómodo sobre los límites de la experimentación. Sin embargo, pocos se pueden acercar por su carácter perturbador al denominado experimento de Little Albert o Pequeño Albert: El salvaje intento por probar con un bebé que las fobias pueden ser condicionadas y aprendidas. Y lo que es peor, conseguirlo.
Esta idea surgió de la mente de John Broadus Watson, reconocido padre de la rama conductista de la psicología, que desde 1913 había comenzado a probar en animales sus tesis. Estas bebían directamente del los estudios de Iván Pavlov, fisiólogo ruso que ganó el Nobel en 1904 por sus estudios sobre el sistema digestivo, pero que también sentó precedentes sobre la psicología.
link por si te interesa:
https://hipertextual.com/2017/10/pequeno-albert
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]
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
What is the net force on a remote controlled airplane if a force of 57.6N is applied West and a force of 95.7N is applied South?
Answer:
112 N at 239°
Explanation:
Applying,
Pythagoras theorem,
a² = b²+c².................. Equation 1
Where a = net force
From the question,
Given: b = 57.6 N, c = 95.7 N
Substitute into equation 1
a² = 57.6²+95.7²
a² = 3317.76+9158.49
a² = 12476.25
a = √12476.25
a = 111.7 N
a ≈ 112 N
Then the direction is given as
∅ = tan⁻¹(c/b)........... Equation 2
∅ = tan⁻¹(95.7/57.6)
∅ = tan⁻¹(1.66)
∅ = 58.9°
∅ ≈ 59°
Since the angle is in the third quadrant,
∅' = 59+180
∅ = 239°
Hence the right answer is
112 N at 239°
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
Ali while driving to school computes the average speed for his trip to be 20km/hr on his return trip along the same route. There is less traffic and average speed is 30km/hr. What is the average speed for Ali's trip?
Answer:
25 km/hr
Explanation:
Since Ali's average speed for his trip to school is u = 20 km/hr and his average speed for the return trip to back home from school is v = 30 km/hr, thus his total average speed for the journey is thus V = (initial average speed + final average speed)/2 = (u + v)/2
Substituting the values of the variables into the equation, we have
V = (u + v)/2
V = (20 km/hr + 30 km/hr)/2
V = 50 km/hr/2
V = 25 km/hr
So, the average speed for Ali's trip is 25 km/hr
Please help
Will give the brainliest!
Answer:
both answer is option C
Explanation:
tag me brainliest
which type of image is formed by convex lens on a screen?
Answer:
The type of image formed on a screen by a convex lens is real, enlarged and inverted.
Explanation:
A lens can be defined as a transparent optical instrument that refracts rays of light to produce a real image.
Basically, there are two (2) main types of lens and these includes;
I. Diverging (concave) lens.
II. Converging (convex) lens.
A converging lens refers to a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image.
Basically, the type of image formed on a screen by a converging (convex) lens is real, enlarged and inverted because it is usually thick across the middle (causing rays of light to converge) but thin at the lower and upper edges.
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.
Which statement or question is a good hypothesis
what is measurement?
[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
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.
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
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
Atoms can create fields to interact with each other without touching.
True
or
False
Answer:
True
Explanation:
True, atoms create electromagnetic fields that form repulsion to keep them from touching.
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
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 .
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 slides down a 28.0 degree ramp with an acceleration of 1.25 m/s2. Determine the coefficient of kinetic friction between
Answer:
[tex]\mu=0.39[/tex]
Explanation:
From the question we are told that:
Angle [tex]\theta=28[/tex]
Acceleration [tex]a=1.25m/s^2[/tex]
Generally the equation for Frictional force is mathematically given by
[tex]F=\muN[/tex]
Where
[tex]N=mgcos \theta[/tex]
[tex]N=mgcos 28[/tex]
Since
Friction force is acting against move of box
Therefore
[tex]mgsin(28) - 1.25m = \mu mgcos(28)[/tex]
[tex]\mu=\frac{gsin(28) - 1.25}{gcos(28)}[/tex]
[tex]\mu=0.39[/tex]
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
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
When extrication will involve cutting the roof off a vehicle, stabilization of the vehicle should include:
Answer:
Deflating the tires by pulling the valve stems
Explanation:
When an accident happens, the EMT process is to take off the top of the vehicle of the highly damaged vehicle so that it can easily be assessed to rescue the vehicle occupants. This creates a bigger exit for the rescuers to take out the people. Vehicle extrication means removing the vehicle from around someone involved in a fatal collision, when other other ways of exiting is not advised or possible. to stabilize the vehicle you have to deflate all tires by pulling the valve stems.
a cyclist has a combined mass of 88 kg and a combined weight of 862.4 then accelerates at 1.2m/s after 2 seconds he reaches a of 2.4m/s what is his momentum at this point
Answer:
shushhhgggvvv vgfxgh
Explanation:
gey laahhg
A stone attached to a string is whirled round in a horizontal circle with constant speed of 10m/s .Calculate the difference in the velocity with the stone is at
I) opposite ends of a diameter
Ii) in two positions A and B where angle AOB is 90° & O is the centre of the circle
Answer:
Stop going on peoples pages and answering random things kid, get a life
Learn to solve problems instead
Explanation:
I answered this because this kid just goes on random pages, and answers incorrectly for points. Check this egirl wannabe's profile
What type of material does not transfer heat well?
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.
