Answer:
A.It’s not moving.
Explanation:
Position-Time graphs display the motion of a object by showing the changes of velocity with respect to time.
The motion of a car on a position-time graph that is represented with a horizontal line indicates that the car has stopped moving.
A straight line with a positive slope indicates that the car is moving at a constant velocity, and thus the slope is constant. On the other hand, a curve with a changing slope, shows that the velocity is changing.
David drives and slows to a stop when he sees a stop sign. A graph of his velocity over time is shown below.
Velocity
20-
P6
15+
As:
10+
MY
5+
Time (s)
Col
t
5
10
15
20
MY
Pro
What is his average acceleration from 10 to 20 seconds?
Pro
Answer:
-2.0
Explanation:
chứng minh mặt trời là nguồn gốc của tất cả nguồn năng lượng
An Excerpt from “Optimism”
by Helen Keller
1 Could we choose our environment, and were desire in human undertakings synonymous with
endowment, all men would, I suppose, be optimists. Certainly most of us regard happiness as
the proper end of all earthly enterprise. The will to be happy animates alike the philosopher, the
prince and the chimney-sweep. No matter how dull, or how mean, or how wise a man is, he feels
that happiness is his indisputable right.
2 It is curious to observe what different ideals of happiness people cherish, and in what singular
places they look for this well-spring of their life. Many look for it in the hoarding of riches, some
in the pride of power, and others in the achievements of art and literature; a few seek it in the
exploration of their own minds, or in the search for knowledge.
3 Most people measure their happiness in terms of physical pleasure and material possession.
Could they win some visible goal which they have set on the horizon, how happy they would be!
Lacking this gift or that circumstance, they would be miserable. If happiness is to be so
measured, I who cannot hear or see have every reason to sit in a corner with folded hands and
weep. If I am happy in spite of my deprivations, if my happiness is so deep that it is a faith, so
thoughtful that it becomes a philosophy of life,—if, in short, I am an optimist, my testimony to
the creed of optimism is worth hearing....
4 Once I knew the depth where no hope was, and darkness lay on the face of all things. Then
love came and set my soul free. Once I knew only darkness and stillness. Now I know hope and
joy. Once I fretted and beat myself against the wall that shut me in. Now I rejoice in the
consciousness that I can think, act and attain heaven. My life was without past or future; death,
the pessimist would say, “a consummation devoutly to be wished.” But a little word from the
fingers of another fell into my hand that clutched at emptiness, and my heart leaped to the
rapture of living. Night fled before the day of thought, and love and joy and hope came up in a
passion of obedience to knowledge. Can anyone who has escaped such captivity, who has felt
the thrill and glory of freedom, be a pessimist?
5 My early experience was thus a leap from bad to good. If I tried, I could not check the
momentum of my first leap out of the dark; to move breast forward is a habit learned suddenly
at that first moment of release and rush into the light. With the first word I used intelligently, I
learned to live, to think, to hope. Darkness cannot shut me in again. I have had a glimpse of the
shore, and can now live by the hope of reaching it.
6 So my optimism is no mild and unreasoning satisfaction. A poet once said I must be happy
because I did not see the bare, cold present, but lived in a beautiful dream. I do live in a
beautiful dream; but that dream is the actual, the present,—not cold, but warm; not bare, but
furnished with a thousand blessings. The very evil which the poet supposed would be a cruel
6) Read the last sentence from the text.
Only by contact with evil could I have learned to feel by contrast the beauty of truth and love and goodness.
Explain how Helen Keller develops this idea in the text. Use specific details to
support your answer.
name a substance which will undergo change E
Answer:
Water
Explanation:
At 0 degrees it's solid...Then it melts into a liquid and at 100 degrees it's gas Simple
A baseball is hit so that it travels straight upward after being struck by the bat. If its initial velocity is 29 m/s , then what is the maximum height that it will reach?
Answer:
Explanation:
Use kinematic equation v² = u² + 2as
Rearrange for distance
s = (v² - u²) / 2a
Realize that at the top of its flight, the ball has zero velocity and gravity is acting downward in an assumed upward positive reference frame.
s = (0² - 29²) / (2(-9.8))
s = 42.90816...
s = 43 m
Which graph uses bars to show data that are broken into intervals?
O A. Scatter plot
O B. Bar graph
O C. Box-and-whisker plot
O D. Histogram
Answer:
A. scatter plot?
Explanation:
I dont really know if I'm right... sorry.
Technician a says that the piston engine starts and stops several times per 2nd technician B says that with the rotary engine each rotor has 3 working chambers so it acts like a 3 cylinder engine while it is at operating
Answer:
Explanation:
trfbehherebgqerfherbfhyqerwbfvhrbhferhgvr
a father pulls his young daughter on a sled (where the combined mass of his daughter and the sled are 40 kg) with a constant velocity up a snowy hill that is inclined at 14 to the horizontal. a) if the coefficient of kinetic friction between the sled's runners and the snow is 0.15, what is the tension force of the rope on which the father pulls
Answer:
Explanation:
We are not told what angle the pull rope is to any other reference. That could make a huge difference in the result.
If we ASSUME that the rope pulls parallel to the slope
Then , if T is rope tension
F = ma
T - mgsinθ - μmgcosθ = m(0)
T = mg(sinθ + μcosθ)
T = 40(9.8)(sin14 + 0.15cos14)
T = 151.88677... 150 N
If the rope pulls the sled at a positive angle relative to the slope, As one might expect from an adult holding the rope, then the tension will be increased because only the Tension portion parallel to the slope causes motion in that direction, but will be decreased because the Normal force, and therefore the friction force, of the slope on the sled will be decreased.
Una masa de aire de 20g absorbe 780 cal. Teniendo en cuenta que su temperatura inicial es de 30°C. Calcular la
temperatura que alcanzo al absorber el calor. Ce:0,24 cal/g °C
Answer:
sorry I don't know the answer
Suppose a ball is dropped from a building. What is the change of velocity between the first and fifth seconds of its flight
Answer: 39.2m/s
Explanation:
Due to the free falling body, the acceleration of the ball is 9.8 m/s^2, and its initial velocity is 0 m/s.
V(t) = g*t
The change of velocity from t=1 to t=5:
Delta V = 9.8*(5-1) = 39.2 m/s
A car with a mass of 1500 kg is pulled by a rope that is horizontal to the ground. The tension in the rope is 2000 N and a friction force of 350 N opposes the car's motion. What is the magnitude of the car's acceleration?
Answer:
Explanation:
Assuming the ground is level as well.
F = ma
a = F/m
a = (2000 - 350) / 1500
a = 1.1 m/s²
The acceleration of the car is 1.1 m/s².
To calculate the magnitude of the acceleration of the car, we use the formula below.
F-F' = ma................ Equation 1Where:
F = Tension in the ropeF' = Friction forcem = mass of the cara = acceleration of the carMake a the subject of the equation
a = (F-F')/m................. Equation 2From the equation,
Given:
F = 2000 NF' = 350 Nm = 1500 kgSubstitute these values into equation 2
a = (2000-350)/1500a = 1650/1500a = 1.1 m/s²Hence, the acceleration of the car is 1.1 m/s².
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What is the kinetic energy of a 36N toy car which is moving at 5 m/s?
HELP PLEASE
What is the correct definition of amplitude?
A. the height of a wave
B. the distance between two crests or troughs
C. the number of complete waves that pass a point in a second
D. the time it takes for one complete wave to pass a given point
Answer:
correct answer is A) the height of a wave
Explanation:
i just did the test:)
The amplitude is used represent the height of the wave.
What is wave?A wave is a disturbance in a medium that carries energy without a net movement of particles. In general, waves are classified into two types as Longitudinal and Transverse
Given is the amplitude of a wave.
Amplitude of a wave is equal to measure of the length of crest or trough. Crest and trough are the points that represents the maximum and minimum displacement of the wave with respect to the reference axis. The crest and the trough points are both at a equal straight line distance from the reference axis. This distance is also called height of the wave. The amplitude is the distance between the centerline and the Crest or trough. The general equation representing the amplitude of wave is x = A sin (ωt + ϕ) or x = A cos (ωt + ϕ) is the formula.
Therefore, the amplitude represents the height of the wave.
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if two masses 5.2kg and 4.8kg are attached to ends of inextensible string passed over a friction less pulley then acceleration of system
Answer:
If two masses 5.2 kg and 4.8 kg are attached to the ends of inextensible strings passed over a frictionless pulley then the acceleration of system is 0.4 ms-2.
Explanation:
When converted to a household measurement, 9 kilograms is approximately equal to a
Answer:
D) 19.8 lbs
Explanation:
1kg in household measurement is equal to 35.274 ounces. 35.274*9=317.466 ounces.
1kg is also equal to 2.205 lbs. 9*2.205=19.8416
9 kg is also equal to 9000 grams, but grams are not a part of the household measurement system
a) 9000 grams. b) 9000 ounces. c) 19.8 ounces. d) 19.8 pounds.
This leaves us with 19.8 lbs
Tell me any 5 importance of medicinal plants
Answer:
Aloe, Tulsi, Neem, Turmeric, and Ginger are medicinal plants that can help with a variety of diseases. Ginger, green tea, walnuts, aloe, pepper, and turmeric are just a few of these plants. Some plants and their derivatives are key sources of active compounds used in aspirin and toothpaste, among other things.
Explanation:
Plant name: Uses:
1. Marshmallow: //// Relief from aching muscles and pain in muscle, Heals insect bite. ////
2.California poppy //// Relieves tension, Removes nervous system
3. Tulsi //// Cures sore throat, Cures fever and asthma
4. Neem //// Cures skin diseases, Cures diabetics
5. Aloevera //// Heals burns, Relieves constipation
(Hope this helps can I pls have brainlist (crown)☺️)
THE BEST ANSWER WILL BE MARKED THE BRAINLIEST!
While driving your car at a fast constant speed, you have to press down hard on your gas pedal than you do while driving at a slower constant speed.
In both cases, the net force on your car is zero. Explain why you have to apply a greater pressure to your gas pedal.
Answer:
You have to apply more pressure to the pedal so more gas runs through the car allowing it to reach higher speeds
To move, a car or any other object must be accelerated from rest to the desired speed; this necessitates that the engine force be greater than the friction force. The net force must be zero once the car is moving at constant velocity; otherwise, the car will accelerate (gain speed).
What forces act on a car at constant speed?All forces acting on a car moving at a constant speed (uniform motion) are balanced. In this case, the two opposing backward forces (air resistance and friction) perfectly balance the applied force of the wheels on the road.When we say constant speed, we mean that a body or object moves at a constant change in distance over time. For example, if we are walking in a straight line at 1 step per second, we can say we are moving at a constant speed. Our acceleration is equal to zero in this case.To learn more about : Speed
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What is the net force on a cart being pushed with an applied force of 23 N with a frictional force of 23 N?
Answer:
1N
Explanation:
Pretty simple Divide 23 by 23 which gives you 1.
23N ÷ 23N = 1N
Answer:
[tex]\sf \longmapsto \: 1 \: N[/tex]
Explanation:
[tex]\sf \longmapsto \frac{23N}{23N} [/tex]
[tex]\sf \longmapsto1 \: N[/tex]
Computes average speed when a person walk for 1 minute at speed of 1.5 m/s and another 1 minute at speed of 3.5 m/s along a straight road
Answer:
2.5 m/s
Explanation:
(60*1.5+60*3.5)/120=2.5
or
(1.5+3.5)/2=2.5
Indicate whether each of the following statements about car collisions is true or false. Select all that are True.
a. If two identical cars with identical speeds collide head on, the magnitude of the impulse received by each car and each driver is the same as if one car at the same speed had collided head on with a concrete wall.
b. Car 1 has mass m, and car 2 has mass 2m. In a head-on collision of these cars while moving at identical speeds in opposite directions, car 1 experiences a bigger acceleration than car 2.
c. The essential safety benefit of crumple zones (parts of the front of a car designed to receive maximum deformation during a head-on collision) is due to their absorbing kinetic energy, converting it into deformation, and lengthening the effective collision time, thus reducing the average force experienced by the driver.
d. Car 1 has mass m, and car 2 has mass 2m. In a head-on collision of these cars while moving at identical speeds in opposite directions, car 1 receives an impulse of bigger magnitude than that received by car 2. If car 1 has mass m and speed v, and car 2 has mass 0.5m and speed 1.5v, then both cars have the same momentum.
Answer:
True statements a, b, and c
Explanation:
Answer d is false because in any collision, each object receives the same impulse. Also the momentum of car 1 is mv, while the momentum of car 2 is 0.5m(1.5v) = 0.75mv
The impulse of collision of cars depends on the mass and velocity of the cars. The statements which are true about the car collisions are option a, b, c.
What is impulse?Impulse is a physical quantity expressed as the product of force and time. The change in momentum mΔV is numerically equals to the impulse F t.
If two identical cars with identical speeds collide head on, the magnitude of the impulse received by each car and each driver is the same as if one car at the same speed had collided head on with a concrete wall. Because they have equal mass and velocity.
The bigger acceleration is experienced by the one which have lighter mass thus car 1 with lower mass experience higher acceleration .
The essential safety benefit of crumple zones (parts of the front of a car designed to receive maximum deformation during a head-on collision) is due to their absorbing kinetic energy.
Converting this energy into deformation, and lengthening the effective collision time, thus reducing the average force experienced by the driver.
The momentum change is proportional to the velocity. The one which have higher velocity is having the higher momentum. Thus car 2 have higher velocity. Thus option d is false.
Therefore, the statements which are true are a, b and c.
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How 2cos theta ×sin theta is =sin2theta
Answer:
Can you rewrite that sorry
Explanation:
When converted to a household measurement, 9 kilograms is approximately equal to a
Answer:
D) 19.8 lbs
Explanation:
1kg in household measurement is equal to 35.274 ounces. 35.274*9=317.466 ounces.
1kg is also equal to 2.205 lbs. 9*2.205=19.8416
9 kg is also equal to 9000 grams, but grams are not a part of the household measurement system
a) 9000 grams. b) 9000 ounces. c) 19.8 ounces. d) 19.8 pounds.
This leaves us with 19.8 lbs
how long untill the semester is done
HELPPP
Which of the following statements about friction is FALSE .
1 ) Friction involves objects that are in physical contact .
2) Friction is less if surfaces are very smooth .
3 ) Friction is always in the direction of the motion .
4) Friction is caused by the uneven surfaces of touching objects
PHYSICISTS NEEDED, THANK YOU, (10 POINTS)
Answer:
would it be 2.66666666667 or 2.7
Explanation:
A car’s velocity as a function of time is given by Vx (t) = α.t + β.t 2 , where α= 3m/s and β= 0.1m/s 3 . Calculate the average acceleration for the time interval
b) t= 5 to t = 10 s
The definition of average acceleration allows to find the result for the average acceleration in the given time interval is:
[tex]a_{average}= 1.5 \ \frac{m}{s^2}[/tex]
Instantaneous acceleration is defined as the derivative of velocity with respect to time.
a = [tex]\frac{dv}{dt}[/tex]
Where a is the acceleration, v the velocity and t the time.
They indicate that the speed of the car is given by the relation.
v = α t + β t²
With α = 3 m / s and β = 0.1 m / s³
Let's make the derivative.
a = α + 2β t
Let's substitute
a = 3 + 2 0.1 t
Average acceleration is the change in velocity in the time interval.
[tex]a_{average} = \frac{\Delta v}{\Delta t }[/tex]
Let's find the velocity at the indicated time.
For t = 5 s
v₅ = 3 + 0.1 5²
v₅ = 5.5 m / s
For t = 10 s
v₁₀ = 3 + 0.1 10²
v₁₀ = 13 m / s
Let's calculate the average acceleration.
[tex]a_{average} = \frac{13 - 5.5 }{ 10 - 5 }\\[/tex]
[tex]a_{average}= 1.5 \ m/s^2[/tex]
In conclusion using the definition of mean acceleration we can find the result for the mean acceleration in the given time interval is:
[tex]a_{average} =[/tex] 1.5 m / s²
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I really need your help I will mark you brainliest!
I have been stuck for 15 minutes!!
Answer the following questions about Hurricane Harvey:
a. Why did hurricane Harvey travel from the east (Africia) twards the west (Florida) when our weather starts in the west and travels east?
B. why did hurricane harvey rotate counterclockwise? Do all hurricanes rotate counterclockwise?
An 80 kg box is accelerated to the right at a rate of 3 m/s2. What is the applied force?
As we know,
F= ma
Here,
applied force(f)= mass × acceleration
=80kg×3m/s2
=240kgm/s2
=240N
Discuss How are the acceleration, the net force, and the mass of
an object related? SC.6.P.13.3
13 SEBS
According to Newton's second law
[tex]\\ \sf\longmapsto Force=Mass\times Acceleration[/tex]
[tex]\\ \sf\longmapsto Mass=\dfrac{Force}{Acceleration}[/tex]
[tex]\\ \sf\longmapsto Acceleration=\dfrac{Force}{Mass}[/tex]
Based on your observations, what can you say about your prediction in Parts A and B above concerning the potential and kinetic energy?
Answer:
Explanation:
My perdiction was correct. I predicted in Part A that the Kinetic Energy would increase. In Part B I predicted that the potential energy would decrease due to the kinetic energy increasing.
I need HELP! IMMEDIATELY!!!
Answer:
Option A
Explanation:
N is Chloroplast, P is a large centralized vacuole and R is the cell wall which are found only in plant cells. Hence, the given cell is a plant cell.
S = Rough Endoplasmic Reticulum
P = Vacuole
O = Nucleus
T = Smooth Endoplasmic Reticulum
U = Golgi Apparatus
N = Chloroplast
U = Cell Membrane
M = Mitochondria
R = Cell wall
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807