A car starts at 80 m/s but sees a cop and hits the brakes slowing down to 50 m/s in 2 sec.

Answers

Answer 1

Answer:

-15m/s/s

Explanation:

Acceleration = change in speed/ change in time

The change in speed is calculated by subtracting the initial speed from the final speed, so the change in speed is: 50 - 80 = -30m/s. The change in time is 2 - 0 = 2.

So the car acceleration is -30/2 = -15m/s/s

It is negative because it is decelerating.

Hope this helped!


Related Questions

A long, thin, insulated wire carries a current I1=1A out of the plane of the paper. The wire is surrounded by a long cylinder of radius a=12cm. The cylinder carries a current I2=9A that is unformly distributed over its cross section and flows into the plane of the paper.
Find the radius r at which the amgnetic field is zero.

Answers

Answer:

The magnetic field is zero at a radius r = 4 cm.

Explanation:

The magnetic field due to the wire is given by B₁ = μ₀I₁/2πr where I₁ = current in wire = 1 A and r = distance of point where magnetic field is zero from wire.

Now, since the current is uniformly distributed in the cross section of the cylinder, its current density is constant.

So, with current I₂ = 9 A flowing in the cylinder and radius, a = 12 cm. Let I' = current at radius r where the magnetic field is zero. So,

I'/πr² = I₂/πa²

I' = I₂r²/a²

Using Ampere's Law, the magnetic field B₂ at the distance r is given by

∫B.ds = μ₀I'

∫Bdscos0 = μ₀I' (since the magnetic field is parallel to the path)

B∫ds = μ₀I'   ∫ds  = 2πr

B2πr = μ₀I'

2Bπr = μ₀I₂r²/a²

B₂ = μ₀I₂r/2πa²

So, when the net magnetic field is zero, B₁ = B₂

So,  μ₀I₁/2πr = μ₀I₂r/2πa²

I₁/r = I₂r/a²

I₁/I₂ = r²/a²

r² = I₁/I₂a²

taking square root of both sides,

r = a√(I₁/I₂)

substituting the values of the variables, we have

r = 12√(1/9)

r = 12/3

r = 4 cm

The magnetic field is zero at a radius r = 4 cm.

A pendulum is 0.760 m long, and the bob has a mass of 1,00 kg. At the bottom of its swing, the bob's speed is 1.60 m/s. The tension is greater than the weight of the bob because Multiple Choice 0 its horizontal component is increasing from zero. O the bob has a downward acceleration, so the net Fy must be downward O O the bob has zero acceleration. O ( the bob has an upward acceleration, so the net Fy must be upward Required information A pendulum is 0.760 m long, and the bob has a mass of 1.00 kg. At the bottom of its swing, the bob's speed is 1.60 m/s. What is the tension in the string at the bottom of the swing?

Answers

Answer:

  T = 13.17 N

the correct one is there is a digested centripetal acceleration towards upward

Explanation:

For this exercise we can use Newton's second law at the bottom of the pendulum's path

we will assume that the upward direction is positive

              T - W = m a

in this case it is describing a circle the acceleration is central

              a = v² / R

where the radius of the trajectories equals the length of the pendulum

             R = L

we substitute

            T = mg + m v² / L

             T = m (g + v² / L)

When reviewing the different statements, the correct one is there is a digested centripetal acceleration towards upward

let's calculate the tension of the rope

             T = 1 (9.8 + 1.6 2 / 0.760)

             T = 13.17 N

Organized procedure to study something under controlled conditions

Answers

what’s your question to that

A watermelon is dropped from the edge of the roof of a build- ing and falls to the ground. You are standing on the sidewalk and see the watermelon falling when it is 30.0 m above the ground. Then 1.50 s after you first spot it, the watermelon lands at your feet. What is the height of the building

Answers

Answer:

The hight of the building is 38.16 m

Explanation:

These two pieces of information given, first, the watermelon is 30 m  above the ground and after 1.50 s the watermelon has been spotted. Now we are required to find the height of the building.

Use the below formula to find the height of buildings.

S = ut + ½ gt^2

30  =1.5u + (1/2) × 9.8 (1.5)^2

u = 12.65 m/sec

v^2 – u^2 = 2gs

(12.65)^2 = 2×9.8 s’

S’ = 8.16 m  

h = s + s’

h = 30 + 8.16 = 38.16 m

The hight of the building is 38.16 m.

The height of the building is 38.16 m.

Given data:

The height above the ground is, h = 30.0 m.

The time interval after observation of first spot is, t = 1.50 s.

We need to find the height of building. And since two pieces of information given, first, the watermelon is 30 m  above the ground and after 1.50 s the watermelon has been spotted. So, using the second kinematic equation of motion as,

[tex]h = ut + \dfrac{1}{2}gt^{2}[/tex]

Here, u is the initial speed. Solving as,

[tex]30 = (u \times 1.50) + \dfrac{1}{2} \times 9.8 \times (1.50)^{2}\\\\u =12.65 \;\rm m/s[/tex]

Now landing distance (s') is calculated using the third kinematic equation of motion as,

[tex]v^{2} =u^{2}+2(-g)s\\\\0^{2} =12.65^{2}+2(-9.8)s\\\\s = 8.16 \;\rm m[/tex]

Then the height of building is given as,

H = h + s

H = 30 m + 8.16 m

H = 38.16 m

Thus, we can conclude that the height of the building is 38.16 m.

Learn more about the kinematic equations of motion here:

https://brainly.com/question/16556016

PLZ PLZ PLZ I VOTE BRAINLY PLZPLZPLZ what is the theory of an atom created by a Dr. VAN C.

Answers

Answer: Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. ... During the 1930s Bohr helped refugees from Nazism.

11. एक समान चुम्बकीय क्षेत्र में लम्बवत प्रवेश करने वाले किसी आवेशित कण द्वारा प्राप्त वृत्तीय पथ की
7 त्रिज्या का सूत्र ज्ञात कीजिए।
2
Find the formula of radius obtained by a charged particle entering perpendicularly
in a uniform magnetic field.​

Answers

Answer:

r=mv/Be

Explanation:

If a positive charge enters a magnetic field at 90 degrees the charge is deflected in a circular path by a force that acts perpendicular to it in line with Flemings right-hand rule

to derive the radius of the path of the charge we apply

F= mv^2/r=Bev

where

m= mass of the electronic charge

e=charge

B=magnetic field

v=average speed

r=radius

 

rearranging we have

r=mv^2/Bev

r=mv/Be

You are jogging with a velocity of 2 meters/second to the west, when you feel thirsty and stops to drink water after 5 seconds. First find your velocity the moment you stopped running. Then, find your acceleration during that motion. What are the units for acceleration? What is the direction of acceleration in this motion? Show your work.

Answers

Answer:

The velocity when the runner stopped is v =0 m/s

The acceleration is [tex]a = 0.4 \ m/s [/tex]

Explanation:

From the question we are told that

The initial velocity is [tex]u = 2 \ m/s[/tex]

The time taken is [tex]t = 5 \ s[/tex]

Generally from the question we are told that the person stopped running so the person velocity at that moment is v =0 m/s

Now the acceleration is mathematically represented as

[tex]a = \frac{v - u}{t}[/tex]

=> [tex]a = \frac{0 - 2}{5}[/tex]

=> [tex]a = 0.4 \ m/s [/tex]

When the sun provides energy for photosynthesis, an interaction with the __________ takes place.

Answers

Answer: chloroplast

Explanation:
The chloroplast are organelles that conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the energy from sunlight

This ball is technology too! It can be
rolled, kicked, or thrown. Is that a need
or a want?

Answers

Answer:

want

Explanation:

people always want the new thing especially if its technology

Wantttttrtttt............

Help please Subject (general psychology)

Answers

Answer:

plz give the question... floor the proper answer

Explanation:

plz mark me add the brainliest

thank

me and follow ma

Let's start by calculating what acceleration the rocket must produce to launch into earth orbit. In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes. What average acceleration is required to accomplish this

Answers

Answer:

30.56 m/s^2

Explanation:

Given that In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes.

The average acceleration that is required to accomplish this will be

Average acceleration = change in velocity / time

Average acceleration = 7700/ 4.2 × 60

Average acceleration = 7700/252

Average acceleration = 30.56 m/s^2

Given three vectors A = 24i + 33j, B = 55i - 12j and C = 2i + 43j (a) Find the magnitude of each vector. (b) Write an expression for the vector difference A - C. (c) Find the magnitude and direction of the vector difference A-B. (d) In a vector diagram show vector A + B, and A - B, and also show that your diagram agrees qualitatively with your answer.

Answers

Answer:

(a) , .  and .

(b)[tex]\vec A - \vec C=22 \hat i -10 \hat j[/tex].

(c)[tex]|\vec A - \vec B|=63.13[/tex] and the direction [tex]\theta =[/tex] 124.56°.

Explanation:

Given that,

,

and

[tex]\vec {C}=2 \hat i +43 \hat j[/tex]

(a) The magnitude of a vector is the square root of the sum of the square of all the components of the vector, i.e. for a ,.

So, the magnitude of the is

[tex]|\vec A|=\sqrt {24^2+ 33^2}[/tex]

[tex]\Rightarrow |\vec A|=\sqrt {1665}[/tex]

.

The magnitude of the is

[tex]|\vec B|=\sqrt {55^2+ (-12)^2}[/tex]

[tex]\Rightarrow |\vec B|=\sqrt {3169}[/tex]

.

And, the magnitude of the is

[tex]|\vec C|=\sqrt {2^2+ 43^2}[/tex]

[tex]\Rightarrow |\vec C|=\sqrt {1853}[/tex]

.

(b) The difference between the two vectors is the difference between the corresponding components of the vectors. So, the required expression of is

[tex]\vec A - \vec C=(24 \hat i +33 \hat j) - (2 \hat i +43 \hat j)[/tex]

[tex]\Rightarrow \vec A - \vec C=24 \hat i +33 \hat j - 2 \hat i -43 \hat j[/tex]

[tex]\Rightarrow \vec A - \vec C=22 \hat i -10 \hat j[/tex]

(c) The expression of is

[tex]\vec A - \vec N=(24 \hat i +33 \hat j) - (55 \hat i -12 \hat j)[/tex]

[tex]\Rightarrow \vec A - \vec B=24 \hat i +33 \hat j - 55\hat i +12 \hat j[/tex]

[tex]\Rightarrow \vec A - \vec B=-31 \hat i +45 \hat j\;\cdots (i)[/tex]

The magnitude of is

[tex]|\vec A - \vec B|=\sqrt {(-31)^2+55^2}[/tex]

[tex]\Rightarrow |\vec A - \vec B|=\sqrt {3986}[/tex]

[tex]\Rightarrow |\vec A - \vec B|=63.13[/tex]

Now, if a vector [tex]\vec V= -\alpha \hat i +\beta \hat j[/tex] in 3rd quadrant having direction [tex]\theta[/tex] with respect to [tex]\hat i[/tex] direction, than

in the anti-clockwise direction.

Here, from equation (i), for the vector [tex]\vec A - \vec C[/tex], [tex]\alpha=31[/tex] and [tex]\beta=45[/tex].

[tex]\Rightarrow \theta = \pi-\tan ^{-1}\left(\frac {45}{31}\right)[/tex]

180°-55.44° [as \pi radian= 180°]

124.56° in the anti-clockwise direction.

(d) Vector diagrams for [tex]\vec A +\vec B[/tex] and [tex]\vec A - \vec B[/tex] has been shown  

in the figure(b) and figure(c) recpectively.

Vector [tex]\vec A - \vec B[/tex] is in 3rd quadrant as calculated in part (c).

While Vector [tex]\vec A +\vec B=(24 \hat i +33 \hat j)+(55 \hat i -12 \hat j)[/tex]

[tex]\Rightarrow \vec A +\vec B=79 \hat i +21 \hat j[/tex], which is in 1st quadrant as both the components are position has been shown in figure(b).

Do states give up all power to withdraw when they join a union of states, or do they still retain some control over their fate?

Answers

Yes if you’re going on the road or you something you can do to get on your way home from the airport if I

Which of the following is not one of the emotional expressions that are universally recognized?
OA. Happiness
OB. Disgust
OC. Sadness
OD. Love
HELPP!

Answers

Answer:

B

Explanation:

The answer should be B.

I need help ASAP plzzz!!!!

Answers

Answer:

1. coffee maker 2.store B. 3.yes 5. 180

If you push a book 1.5 m across a table using a constant force of 10.0 N, how much work do you
do on the book?

Answers

Answer:

The answer is

15.0 J

Explanation:

To calculate the work done by a body we use the formula

work done = force × distance

From the question

force = 10 N

distance covered = 1.5 m

So the work done is

work done = 10 × 1.5

We have the final answer as

15.0 J

Hope this helps you

What contributions did Johannesburg Kepler make

Answers

Answer:

Multiple

Explanation:

He was the first to determine that refraction drives vision in the eye. Using two eyes enables depth perception. Kepler is also known for defining laws regarding planetary motion.

Physics Question (attached)

Answers

Answer:

The answer is "[tex]\bold{10.6 \ \ \frac{m}{s^2}}[/tex]"

Explanation:

The  Formula of acceleration:

[tex]\bold{a= \frac{v-v_0}{t}}[/tex]

Given value:

[tex]t= 50\\v= 856\\v_0= 324[/tex]

Calculating the acceleration:

[tex]\to a = \frac{(856 - 324)}{50}\\\\[/tex]

       [tex]= \frac{(532)}{50}\\\\= \frac{(106.4)}{10}\\\\= 10.64 \ \ \frac{ m}{s^2}[/tex]

What is the dependent variable in this hypothesis?
After finding that objects of the same mass do not
always float or submerge the same way in a tub of
liquid, Alexis wrote a new hypothesis to test objects that
have the same mass.
o the mass of the object
O the surface area of the object
O the amount of water displaced
O the height at which the object floats
If the surface area of an object increases, then it
will float higher in the tub, because the object
would need to displace more liquid in order to sink
all the way down.

Answers

Answer:

The height at wich the object floats

Explain

took on edge 2020

Answer:

the height at which the object floats

Edge 2021

What the answers due in 2 min

Answers

Hello ┬┴┬┴┤◕3◕)づ├┬┴┬┴

The answer is 3 m

the gap in between 4s and 6s is 5s

you follow your finger up to the purple like, and follow the purple line in a straight line to the left. It ends at 3m and that is your answer.

A 0.091-in-diameter electrical wire at 90°F is covered by 0.02-in-thick plastic insulation (k = 0.075 Btu/h·ft·°F). The wire is exposed to a medium at 50°F, with a combined convection and radiation heat transfer coefficient of 2.5 Btu/h·ft2·°F. Calculate the critical radius (rcr) of the plastic insulation (in inches).

Answers

Answer:

The critical radius of the plastic insulation is 0.72 inches.

Explanation:

Given that,

Diameter = 0.091 in

Thickness = 0.02 in

Initial temperature = 90°F

Final temperature = 50°F

Heat transfer coefficient = 2.5 Btu/h.ft²°F

Material conductivity = 0.075 Btu/h.ft °F

We need to calculate the critical radius of the plastic insulation

Using formula of critical radius

[tex]r_{cr}=\dfrac{2K}{h}[/tex]

Where, k = Material conductivity

h = Heat transfer coefficient

Put the value into the formula

[tex]r_{cr}=\dfrac{2\times0.075}{2.5}[/tex]

[tex]r_{cr}=0.06\ ft[/tex]

[tex]r_{cr}=0.72\ inches[/tex]

Hence, The critical radius of the plastic insulation is 0.72 inches.

Using the equation for Impact, can you explain the following:
Why are car steering rods designed to collapse?
Why are highway guard rails designed to crumple up on impact?
Why are traffic saftey barrels filled with water or sand?

Answers

Explanation:

Equation for Impact

FΔt = ΔP,

F = force

Δt  = Impact of time

ΔP = Change in momentum

Car steering is engineered to fail in order to maximize the time of contact and hence reduce the initial impact and mitigate the damage incurred.

Road guard railing crumple on contact to maximize impact time and hence reduce impact intensity and mitigate damage.

Road safety containers are loaded with liquid or sand as they improve the period of impact.

The x vector component of a displacement vector has a magnitude of 94.8 m and points along the negative x axis. The y vector component has a magnitude of 149 m and points along the negative y axis. Find (a) the magnitude and (b) direction of . Specify the direction as a positive angle with respect to the negative x axis.

Answers

Answer:

We use pythagorean theorem

So that

r = √(x² + y²)

r = √(94.8)² + (-149)² )

r =√ 9682.6 + 22201

= 178.6

direction we use

စ = tan^-1(98.4/149)

= tan^-1 (0.6604)°

Drive-reduction theory states that motivation comes from a combination of both reinforcement and drive.
ОА.
True
OB. False

Answers

The correct answer is A) True

Father drove 176 km in 7 hours. For the first 92 km, he spent
for 4 hours. What was his average speed for the remaining
journey?
km/h

Answers

Answer:

28km/h

Explanation:

92km = 4 hours

176 - 92 = 84

84km = 3 hours

84/3 = 28

28km/h

Hopefully this helps you :)

pls mark brainlest ;)

Calculate the average speed 

1) between 0 min and 3 min.


2) between 3 min and 5 min. 



3) between 5 min and  10 min 


4) between 0 min and 10 min​

Answers

Answer:

000000000000000000000000000

You walk 10 meters to class in 20 seconds , your average speed is ___ ?

Answers

2 seconds per 1 meter. (20/10=2/1)

The average speed is 1/2 m/s.

To determine the answer, we need to know about average speed.

What is average speed?

Distance covered by an object per unit time is known as average speed.

What is the mathematical formula of average speed?

Mathematically, average speed= Total distance travelled/ total time taken

What is the average speed, if I walk 10 metes in 20s?

Here, total distance travelled = 10m,

         total time taken = 20s

 Average speed = 10/20 = 1/2 m/s

Thus, we can conclude that the average speed is 1/2 m/s.

Learn more about average speed here:

https://brainly.com/question/4931057

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What is the speed of an object that travels 60 meters in 4 seconds?

Answers

Answer:

15 m/s

Explanation:

s=d/t

s=60/4

s=15 m/s

Answer:

The answer would be 15 m/s

Explanation:

s=d/t

s=60/4

s= 15 m/s

Have a beautiful day beautiful

You welcome.

Why is it important not to present a biased argument as a public speaker?
A.
Because it is unconvincing
B.
Because it is immoral
C.
Because it is unfair
D.
Because it is pointless

Answers

Answer:

Explanation:

a) because it's immoral as you're trying to convince people of your views when you should be giving both sides of the story so people are able to come up with their own opinions on what you're talking about

A sports car starts from rest at an intersection and accelerates toward the east on a straight road at 9.0 m/s2. Just as the sports car starts to move, a bus traveling east at a constant 16 m/s on the same straight road passes the sports car. When the sports car catches up with and passes the bus, how much time has elapsed

Answers

Answer:

3.6s

Explanation:

Have In mind that the sports car will catch up with bus when their positions are equal

So

S = ut + 1/2at²

where u is initial velocity

For sports car we have

x = 0 + 1/2 x 9 x t²

For Bus

S= 16ts + 0

Equating the two

1/2 x 9 x t² = 16t

4.5 x t = 16

t = 3.6s

Other Questions
Describe how an atlatl was useful to early people in the southwest. 50 POINTS QUESTION!!!!! Refer to the passage. "We, considering the grave inconveniences which might come from the lack especially of ploughmen and such labourers, have held deliberation and treaty concerning this with the prelates and nobles and other learned men sitting by us; by whose consentient counsel we have seen fit to ordain: that every man and woman of our kingdom of England, of whatever condition, whether bond or free, who is able bodied and below the age of sixty years, not living from trade nor carrying on a fixed craft, nor having of his own the means of living, or land of his own with regard to the cultivation of which he might occupy himself, and not serving another, if he, considering his station, be sought after to serve in a suitable service, he shall be bound to serve him who has seen fit so to seek after him; and he shall take only the wages liveries, meed or salary which, in the places where he sought to serve, were accustomed to be paid in the twentieth year of our reign of England, or the five or six common years next preceding. How did the Statute of Laborers and the pressures of the Hundred Years War contribute to the Peasants Revolt of 1381? Serfs saw the government enforce this law laxly because of the demands of the war and moved to liberate themselves. Serfs were often forcibly taken to work on estates after fighting in the wars, which built up considerable anger. Serfs became unproductive because of the low pay that they received, which, combined with the war, led to food shortages and social unrest. Serfs rebelled in part because of low pay from lords, high taxes to fund the war, and the governments role in enforcing this law. Which of the following did Robert La Follette propose for election reform? A. changing the voting requirements B. removing candidate age restrictions C. limiting campaign contributions D. lowering the voting age is the inequality always sometimes or never true?9x+2(2+x) use public policy in a sentence 10. What must first be done before treating an animal for a behavioral problem? O A. Ruling out a medical problem O B. Giving the animal a behavioral exam C. Changing the environment OD. Prescribing medication describe the domain and range What is the speed of an object that travels 20 meters in 4 seconds? what best describes the connotation given to the word mercy in these chapters aka (call of the wild) a)weaknessB)betrayalC)deathD)thievery Which led to the formation of oceans after water on Earths surface evaporated? A student conducted an experiment with two rose plants to determine if a liquid formula for fertilizer produced greater growth than a dry formula. After testing each fertilizer on two different plants for one month, his data led to the conclusion that the liquid formula was a better promoter of plant growth. When he described his conclusion to his teacher, she told him he needed to conduct additional trials. The teacher most likely asked for additional trials because she did not believe the new formula helped plants grow better than the old formula. it was necessary to see data from more plants before the conclusion could be accepted. it was necessary to have tested the fertilizer on different kinds of plants. she thought he should test additional fertilizer formulas on the same two plants. Help!! no can seem to help me :/ What is the theme of cask of amontillado? I NEED HELP NOW! Five students labeled a base, B, and a corresponding height, H, for each of these Parallelograms. Are all the drawings? Explain your reasoning. A student clicks the mouse at time intervals of 1.60, 2.10, 2.40, 1.90 what is the standard deviation of this dataset. A. 0.22B. 0.25C. 0.29D. 0.58 The Arab Spring is best described as A The violent reaction of Arab dictators to the 2011 protests against them.B the Arab governments' acceptance and incorporation of democratic ideologies. C the quiet period that followed the 2011 protests against Arab dictatorships.D the protests carried out in 2011 against dictatorships in many Arab states. describe the motion of objects that are viewed from your reference frame from both inside and while you travel inside a moving vehicle Want more easy points?? :D What is your favorite food? Mines Lasagna! YUM Best answer gets marked brainliest! What is true about connectionless packet switched networks? a. each datagram must contain both source and destination addresses b. without a connection, datagrams may not arrive in sequential order at the destination c. establishment of a connection between communicating points is not required prior to exchanging datagrams, thus reducing overhead communications d. all of the above are true the art of science of plotting determining or directing the course of travel is called ____