can someone explain it with steps?

A car was moving on a road at a constant speed of 15 m/s when suddenly the car driver saw some animal on the road at a distance of 21 m from the car, so he applied the brakes after a response time of 0.4 s and stopped before hitting the animal by 1 m. What was the deceleration of the car?

a-7.5 m/s^2

b-5.2 m/s^2

c-8.0 m/s^2

d-5.6 m/s^2​

Answers

Answer 1

Answer:

Option C is the correct answer

Explanation:

Distance travelled by car during reaction time

[tex]=15\times0.4\\\\=6m[/tex]

The car stopped before hitting the animal by [tex]1 m[/tex]

Distance travelled during deceleration is [tex]21-6-1=14m[/tex]

Hence by [tex]v^2=u^2+2as[/tex]

We have

[tex]0^2=15^2+2 \cdot a \cdot 14\\\\a=\frac{-225}{28} \\\\=-8.03m/s^2[/tex]

Option C is the correct answer

Answer 2
Initial velocity=15m/s=uFinal velocity=0deacceleration=a

Distance traveled during reaction time

15(0.4)=6m

Total distance

21-6-1=14m

[tex]\\ \sf\longmapsto v^2-u^2=2as[/tex]

[tex]\\ \sf\longmapsto -(15)^2=2(14)a[/tex]

[tex]\\ \sf\longmapsto -225=28a[/tex]

[tex]\\ \sf\longmapsto a=-8.0m/s^2[/tex]


Related Questions

a 3 kg rock is falling from a rock ledge in the absence of air resistance how much force will the rock strikes the ground with

Answers

Answer:

papi sus

Explanation:

how much force would be needed to push a box weighing 30 N up a ramp that ahas an ideal mechanical advantage of 3

Answers

Answer:

60n would be the needed force

The force needed to push a box weighing 30 N up a ramp that has an ideal mechanical advantage of 3 is equal to 10 N.

What is the mechanical advantage?

The mechanical advantage can be described as the ratio of the input force to the output force. The mechanical advantage of any machine can be determined by the ratio of the forces involved to do the work.

The ratio of the resistance force to the effort is called the actual mechanical advantage which will be comparatively less. The efficiency of a machine is always determined by equating the ratio of its output to its input.

The efficiency of the machine is equal to the ratio of the actual mechanical advantage (M.A.) and theoretical mechanical advantage. Mechanical advantage can be defined as the force produced by a machine to the force applied to it.

Given the load = 30 N and the ideal mechanical advantage = 3

Mechanical advantage = Load/ Effort

Input force or effort = Load/ M.A.

Force = 30/3

Input Force = 10 N

Learn more about the Mechanical advantage,  here:

brainly.com/question/16617083

#SPJ2

A 2-column table with 5 rows. The first column has entries empty, time of trial number 1 (seconds), time of trial number 2 (seconds), time of trial number 3 (seconds), average time (seconds). The second column labeled one quarter checkpoint has entries 2. 15, 2. 05, 02. 02, 02. 7. Use the table to answer the questions. What is the fastest time trial for the first quarter checkpoint? seconds What is the slowest time trial for the first quarter checkpoint? seconds What is the range of times measured for this checkpoint? seconds.

Answers

The fastest time trial for the first quarter checkpoint is 2.02 s.

The slowest time trial for the first quarter checkpoint is 2.7 s.

The range of the times measured for the checkpoint is 0.68 s.

The given parameters;

Time for quarter checkpoint, = 2.15, 2.05, 2.02, 2.7

The fastest time trial for the first quarter checkpoint is the least measured time value.

fastest time trial = least time measured

fastest time trial =  2.02 s

The slowest time trial for the first quarter checkpoint is the highest measured time value.

slowest time trial = 2.7 s

The range of the times measured for the checkpoint is difference between the fastest time and slowest time.

Range = fastest time - slowest time

Range = 2.7 - 2.02

Range = 0.68 s

Learn more about range of data here: https://brainly.com/question/24326172

Answer:

2.02, 2.15, 0.13

Explanation:

A 2-column table with 5 rows. The first column has entries empty, time of trial number 1 (seconds), time of trial number 2 (seconds), time of trial number 3 (seconds), average time (seconds). The second column labeled one quarter checkpoint has entries 2.15, 2.05, 2.02, 2.07.

Use the table to answer the questions.

What is the fastest time trial for the first quarter checkpoint?

2.02

seconds

What is the slowest time trial for the first quarter checkpoint?

2.15 seconds

What is the range of times measured for this checkpoint?

0.13 seconds

Which would ba another example of newtons first law?

Answers

For example, a book resting on a table applies a downward force equal to its weight on the table. According to the third law, the table applies an equal and opposite force to the book.

A car travels 80 km at an avarage speed of 40 km/h. It travels the remaining distance in 3h. What is its dis placement if the average speed of the car is 30 km/h.? And explain

A) 100 km

B)120 km

C)150km

D)180km

Answers

When traveling with average speed 40 km/h, the car would cover a distance of 80 km in time t such that

40 km/h = (80 km) / t   ⇒   t = 2 h

so the total travel time is 2 h + 3 h = 5 h.

Average speed is defined as the total distance traveled divided by the time it took to cover that distance. So if the overall average speed was 30 km/h, then

30 km/h = (80 km + x) / (5 h)   ⇒   x = 70 km

where x is the distance traveled in the last 3 h of the trip.

Then the total displacement of the car is 80 km + 70 km = 150 km.

Student 1 lifts a box with a force of 500 N and sets it on a tabletop 1.2 m high. Student 2 pushes an identical box up a 5 m ramp from the floor to the top of the same table. Which student did the MOST work?

Answers

The student who did the most work is student 2 with 2500 Joules.

Given the following data:

Force 1 = 500 NewtonDistance 1 = 1.2 meterForce 2 = 500 NewtonDistance 2 = 5 meter

To determine which of the students did the most work:

Mathematically, the work done by an object is given by the formula;

[tex]Work\;done = Force \times distance[/tex]

For student 1:

[tex]Work\;done = 500 \times 1.2[/tex]

Work done = 600 Joules

For student 2:

[tex]Work\;done = 500 \times 5[/tex]

Work done = 2500 Joules.

Therefore, the student who did the most work is student 2 with 2500 Joules.

Read more: Read more: brainly.com/question/13818347

Answer:student 2 did the most work

Explanation:student 2 did more work because he pushed it up 5 m instead of 1.2.

If the road becomes wet or crowded, you should ____. slow down and increase your following distance All choices are incorrect. maintain your speed and following distance speed up and decrease your following distance Submit answer

Answers

Answer:

The first one.

If the road becomes wet or crowded, you should ___ slow down and increase your following distance_

What is meant by surface distance ?

The safe distance between vehicles traveling in column specified by the command in light of safety requirements

The slower speed will help you save gas and avoid potential accidents. You can easily eliminate chances of rear end collision by maintaining a safe distance between your car and the vehicles ahead.

hence , a) slow down and increase your following distance is a correct option

learn more about safe distance

https://brainly.com/question/4144073?referrer=searchResults

#SPJ2

please help me !! i’ll mark brainliest if you’re right!

Answers

Option 2nd is the answer

according to newton, doubling the distance between two interacting objects:

Answers

Answer:

So as two objects are separated from each other, the force of gravitational attraction between them also decreases. If the separation distance between two objects is doubled (increased by a factor of 2), then the force of gravitational attraction is decreased by a factor of 4 (2 raised to the second power).

Explanation:

hope his helps

what is the meaning of " hi baby girl "

Answers

Explanation:

it's mean hI small little cute baby girl ...

A race car makes one lap around a track of radius 180 m in 90.0 s. What is the centripetal acceleration in m/s2?
a
0.5
12.6
Ob
OC
Od
.87
2.
2

Answers

Answer:

0.9m/s^2 (yours is 0.87, so choose that)

Explanation:

formula for centripetal acceleration:

v^2/r

to find v, we know that f=1/90s, and r=180m.

v=(2pir)/T

v=(2pi(180))/90

v=12.6m/s

now plug into a=v^2/r

a=(12.6)^2/180

a=0.9m/s^2

A 6 kilogram block in outer space is moving at -100 m/s (to the left). It suddenly experiences three forces as shown below.

B) What equilibrant force is required to keep the block at rest once it does?


C) If you were to rearrange the three forces as you like, what maximum force could be applied to slow the block?


D) How much time would it take for the block to stop under maximum force conditions?

Answers

Newton's second law and the kinematic relations allow to find the results for the questions about forces and the movement of the block are:

    B) the force applied to maintain the system is equilibrium is: F = 0.39 N with an angle of tea = 180º

    C) The maximum force is: F = 24 N

    D) The time to stop the block is: t = 25 s

 

Newton's second law establishes a relationship between the net force, the mass, and the acceleration of the body. In the special case that the acceleration is zero it is called the equilibrium condition.

B) They indicate a diagram of forces on the block, let's look for the components of the force that the block maintains with zero acceleration, in the attached we have a free-body diagram including the force applied to keep the system in equilibrium.

x-axis

      -10 + 12 sin 60 + Fₓ = 0

        Fₓ = 10- 12 sin 60 = -0.39 N

y-axis

       12 cos 60 - 6 + F_y = 0

        F_y = 6 - 12 cos 60 = 0 N

We can give the result of the force in two ways:

Form of coordinates F = -0.39 i ^ N Form of module and angle.

Let's use Pythagoras' theorem to find the modulus.

       [tex]F = \sqrt{F_x^2 + F_y^2 } \\F = \sqrt{0.39^2 +0^2}[/tex]  

       F = 0.39N

We use trigonometry for the angle.

       [tex]tan \theta = \frac{F_y}{F_x}[/tex]

       tan θ=  0º

The component of the force is negative therefore this angle is in the second quadrant, to measure the angle from the positive side of the x axis in a counterclockwise direction.

        θ = 180 + θ'

        θ = 180 + 0

        θ = 180º

C) if the three forces can be moved and the maximum force occurs when they are all linear.

          10+ 6 + 6 + F = 0

          F = -24 N

D) if we maintain this force and eliminate the other three, the block stops, let's look for its acceleration.

          [tex]a = \frac{F}{m}[/tex]  

          a = [tex]\frac{24}{6}[/tex]  

         a =  4 m / s²

The acceleration is in the opposite direction of the initial velocity of the block v₀ = -100 m / s

If we use kinematic relations.

        v = v₀ - a t

Final velocity when stopped is zero

         t = [tex]\frac{0-v_o}{a}[/tex]

         t = 100/4

         t = 25 s

In conclusion using Newton's second law and the kinematics relations we can find the results for the questions about the forces and the motion of the block are:

    B) the force applied to maintain the system is equilibrium is: F = 0.39 N with an angle of tea = 180º

    C) The maximum force is: F = 24 N

    D) The time to stop the block is: t = 25 s

Learn more about Newton's second law here: brainly.com/question/25545050

A roller coaster
produces acceleration due
to changes in both speed
and direction. Applying
Concepts Describe the
acceleration occuring at this
instant on the
rollercoaster ride.

Answers

Answer:

the answer is the rollar coster

Explanation:

because the rollar coster is

NEED HELP ASAP PLEASE
The drop time can be calculated as follows t = sqrt((2y)/g) where y is the vertical height of the table and g is the acceleration due to gravity (9.80 m/)How did the calculated drop time compare to the average of your measured drop times? Find the percent error using the following equation measured drop time - calculated drop time % 100 calculated drop time What factors might cause the differences?

Answers

did you end up getting the answer- im struggling

Answer:

I would think human error could cause differences like not pressing the stop watch on time.

Explanation:

Help it’s multiple choice 11 through 15 please!

Answers

1. • Here, force of gravity on the block = 20 N.

• Therefore, the normal force will also be the same, i.e., 20 N [According to Newton's Third Law, on every action, there is an equal and opposite reaction]

• The coefficient

[tex] u_{k} = 0.4[/tex]

• Force of friction =

[tex]u_{k} \times \: normal \: \: \: force \\ = 0.4 \times 20N \\ = 8N[/tex]

• Hence, the force of sliding friction between the block and the ground is 8 N.

• So, it is option c. 8 N

2. The answer is option d. continue in the same direction with no change in speed.

We know, force = mass × acceleration. When force is 0, then acceleration will also be 0 since mass cannot be 0. So, there will be no change in speed.

3. It is option b. force that is required to give a one kilogram object the acceleration of 1 m/s^2.

Newton is the SI unit of force. As mentioned earlier, force = mass × acceleration. The SI unit of mass and acceleration is Kg and m/s^2 respectively.

So, 1 N = 1 Kg × 1 m/s^2.

4. It is d. not zero.

Acceleration is the change in speed. So, if the force is zero, then acceleration will not occur.

5. Force = 2 N

Acceleration of the object A = 2 m/s^2.

Acceleration of the object B = 1 m/s^2.

Therefore, mass of the object A = 2 N ÷ 2 m/s^2 = 1 Kg

And, mass of the object B = 2 N ÷ 1 m/s^2 = 2 Kg

So, the mass of object B is greater than that of object A.

Hence, the answer is option c. Object B has more mass.

Hope you could get an idea from here.

Doubt clarification - use comment section.

what is the prmary source of energy inside of the earth

Answers

The correct answer is the energy of the sun
The primary source would be the sun

What is the half-life of an isotope if after 30 days you have 31.25 g remaining from a 250 g beginning sample size?

Answers

The half-life of the given isotope will be 10 days, if after 30 days only 31.25 grams are remaining from a sample of 250 grams of the sample size taken in the beginning.

What is Half-life of an element?

The Half-life is the time which is required for a quantity to reduce the content to half of the amount present as its initial value. The term is used in nuclear physics to describe how quickly an unstable atom undergo radioactive decay or how long does stable atoms survive. The term is also used generally to characterize any type of exponential decay.

The half-life of the isotope can be calculated by the formula:

FR = 0.5n

FR = Fraction Remaining = 31.25 g / 250.0 g = 0.1250

n = number of half lives elapsed = ?

0.125 = 0.5n

log 0.125 = n log 0.5

-0.9031 = -0.3010 n

n = 3.000 half lives have elapsed

3 half lives = 30 days

1 half live = 10 days

Therefore, the half-life of the isotope will be 10 days.

Learn more about Half-life here:

https://brainly.com/question/24710827

#SPJ2

Where is iron made?

need help

Answers

Answer:
Nature- Iron is found in the earths crust.
Other- Iron can be found made in China, Australia, Brazil, India, Russia and many more.
Hope this helps!

Answer:

Explanation:

Do you mean "made" as in the element itself, or "made" as it is extracted from the Earth and refined.

====

The elements originate in the stars.  The fusion reactions in Earth's sun fuse hydrogen and helium atoms to make elements, up to iron.  Larger stars and powerful explosions such as supernova create the larger elements.  Humans, with the use of particle accelerators make even larger elements, nearly all of which are unstable and decay rapidly into smaller elements.  But their creation does offer the perk of naming rights if you can prove it was created, and don't pick a clearly untenable name.

The Fe in stardust from the sun collects in clumps via gravitational forces and, via meteorites, is carried to Earth.  This is the major source for pure iron on the Earth.

Iron has chemical properties that lead to it reacting with other substances (e.g., oxygen) and then becoming concentrated in deposits as a variety of salts  in the Earth's crust, as a result of natural processes.  These deposits are mined and the rock is heated to separate and purify the iron metal.

Which of the following is an example of physical weathering?
O calcium carbonate in limestone changes to calcium hydrogen carbonate
O flow water carves erosion channels in a hillside
Ostalactites precipitate in a cave
O acid rain corrodes a monument

Answers

Answer:

acid rain corrodes a monument. d.

Explanation:it only makes sense because its doing something to a physical object.and the other ones aren't.

what has to increase in order for an object to accelerate?

Answers

Answer:

Answer: B. Explanation: For an object to accelerate the force on it must be increased. According to Newton's second law of motion.

Explanation:

I do Accelerate to good luck

The mass of a sample of sodium bicarbonate is 2. 1 kilograms (kg). There are 1,000 grams (g) in 1 kg, and 1 Times. 109 nanograms (ng) in 1 g. What is the mass of this sample in ng? 2. 1 Times. 103 ng 2. 1 Times. 106 ng 2. 1 Times. 109 ng 2. 1 Times. 1012 ng.

Answers

2.1 kg of sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample. Option D is correct.

Mass is the quantity of the substance in the body or object. The SI unit of mass is Kilogram.

There are other units of measure,

Milligram: 1 g is equal to the [tex]\bold {10^3 \ mg}[/tex]Micro-gram: 1 g is equal to [tex]\bold {10^{6} \ \mu g}[/tex]Nano-gram: 1 g is  is equal to[tex]\bold {10^{9} \ ng}[/tex]

First convert kg to gram,

Since, 1 Kg = 1000 g

2.1 kg = grams of sample

So,

Do the cross multiplication,

[tex]\rm mass\ of\ sample = \dfrac {2.1\ kg \times 1000\ g }{ 1 kg}\\\\\rm mass\ of\ sample =2100 g[/tex]

Now, convert 2100 g to nano-grams

Since, 1 g = 1 x 10⁹ ng

2100 g = ng of sample

So,

Do the cross multiplication,

[tex]\rm mass\ of\ sample = \dfrac {2100 g \times 1 \times 10^9 ng }{1\ g}\\\\\rm mass\ of\ sample = 2.1 \times 10^1^2 ng[/tex]

Therefore, 2.1 kg of  sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample.

To know more about Mass units,

https://brainly.com/question/489186

9. How are ecological footprints useful?

Answers


As ecological footprints provide an easily communicable way of measuring the ecological bottom‐line condition for sustainability, it is a useful tool for promoting a sustainable future. It is particularly useful for cities, as it is in cities where the battle for sustainability will be won or lost.

Answer:

This is what the Ecological Footprint does: It measures the biologically productive area needed to provide for everything that people demand from nature: fruits and vegetables, meat, fish, wood, cotton and other fibres, as well as absorption of carbon dioxide from fossil fuel burning and space for buildings and roads.

Why it's useful:

Ecological footprint (EF), measure of the demands made by a person or group of people on global natural resources. It has become one of the most widely used measures of humanity’s effect upon the environment and has been used to highlight both the apparent unsustainability of current practices and the inequalities in resource consumption between and within countries.

Which type of border shows the division between Sonora and Chihuahua?

National border
State border
Physical boundary
Natural boundary

Answers

The answer is the national border

1) A plane takes off from an O'Hare runway heading due west with a speed of 210.1 m/s. Once in the air, it encounters a north wind (blowing south) with a speed of 55.0 m/s. What is the magnitude of its velocity relative to the ground?

2) What is the direction of the resulting velocity (relative to its initial direction)?

Answers

I found this online Idek if it helps but First, determine how many degrees off the runway heading the reported wind is. So if you’re landing Runway 18 and the wind is 160 at 10, the wind is 20 degrees off the runway (180-160=20) . Now picture an analog clock face. How far is the wind angle number in minutes around the clock face? A wind angle of 20 degrees means 20 minutes around the clock face, which is one-third of the way around the clock face The crosswind component is one-third of the total wind. In this example, 10 knots * 1/3 = 3.3 knots of crosswind.

If you like charts, you can lay out common numbers and interpolate between them:

10-degree wind angle 10 minutes, which is 1/6 around clockface crosswind = 1/6 * total wind
15-degree wind angle 15 minutes, which is 1/4 around clockface crosswind = 1/4 * total wind
20-degree wind angle 20 minutes, which is 1/3 around clockface crosswind = 1/3 * total wind
30-degree wind angle 30 minutes, which is 1/2 around clockface crosswind = 1/2 * total wind
45-degree wind angle 45 minutes, which is 3/4 around clockface crosswind = 3/4 * total wind
60-degree wind angle or more 60 minutes, which is 100 percent of the way around a clockface crosswind component ≈ total wind speed

The Doppler technique for planet detection has found Earth-like planets around nearby Sun-like stars. (True or False) ____________________

Answers

Answer: false

Explanation:


An airplane initially travels at 12 m/s when passing the "acceleration line." The airplane then
accelerates to 9 m/s2 until reaching its take off velocity of 40.0 m/s. What is the displacement of
the plane during the acceleration?

Answers

The displacement of  the plane during the acceleration is equal to 80.89 meters.

Given the following data:

Initial velocity = 12 m/sFinal velocity = 40 m/sAcceleration = 9 [tex]m/s^2[/tex]

To determine the displacement of  the plane during the acceleration, we would use the third equation of motion;

[tex]V^2 = U^2 + 2aS[/tex]

Where:

V is the final speed.U is the initial speed.a is the acceleration.S is the displacement traveled.

Substituting the given parameters into the formula, we have;

[tex]40^2 =12^2 + 2(9)S\\\\1600=144+18S\\\\18S=1600-144\\\\18S=1456\\\\S=\frac{1456}{18}[/tex]

Displacement, S = 80.89 meters.

Read more: https://brainly.com/question/13086772

Two students are sitting on a see-saw. The length of the board is 2 meters with the
pivot point being in the very center. One student sitting on the end of the left side
has a mass of 34 kg. If the student sitting on the right has a mass of 42.5 kg, where
should she sit for the see-saw to be in equilibrium?

Answers

To solve the problem it is necessary to apply the concepts of Torque and equilibrium.

The Torque is defined as:

Where

F= Force

d = Distance

In this particular case, the force is caused by the weight of both children.

In turn, when there is equilibrium, the two torques must be equal therefore

Replacing with our values

Re-arrange to find  

Therefore the distance that the second kid should sit to balance the see-saw is 1.8m from the pivot.

why is water soaked cloth used on forehead during fever?please can you tell me answer​

Answers

Answer:

This is because the cloth soaked in water can absorb and evaporate the heat from your forehead.

Explanation:

This technique is used to cool down your fever, and to help you feel better.

in what direction will the seesaw rotate and what will the sign of the angular acceleration be?

Answers

Answer:

It can rotate in any direction. The sign of the angular acceleration depends on how you set the reference system, it can be both negative or positive.

What is the low end of the range of surface temperature for blue white stars

Answers

B 10,000 - 30,000 K Blue-white stars

A 7,500 - 10,000 K White stars

F 6,000 - 7,500 K Yellow-white stars

G 5,000 - 6,000 K Yellow stars (like the Sun)

The lowest temperature stars are red while the hottest stars are blue. Astronomers are able to measure the temperatures of the surfaces of stars by comparing their spectra to the spectrum of a black body.

Other Questions
"1.What sorts of problems does this declaration imagine being solved through science and technology?" Extra Credit #4What are the next two numbers in this pattern?4311413111114111321311431131211 soaps do not work well in hard waters. But they can still be effected it large quantities of soap are added to water. Explain why. Siddhartha Gautama was born a wealthy prince and ended up becoming Buddha, which means the "the Enlightened One", he spent the rest of his life traveling across India sharing his message and learning.truefalse There is a rack of 7 billiards balls, numbered from 1 to 7. If one ball is selected at random, determine the odds against it being an odd-numbered ball.The odds are 0:0(Type whole numbers. Simplify your answer.) Do family psychologists help couples? Explain. Write something about this picture(10 minute writing) What were the advantages the Persian army have against the Greeks at the battle of Thermopylae? Is (x+1) a factor of the function f(x)=7x45x310x2+2x, and why? What are the common factors of 45 and 272O A 1,36.9.150B. 1.39C 1.3.9.15D. 1,3,5,9 What properties are changed when glass breaks? Which description best describes the three-dimensional objectthat is formed when the shape is rotated about the axis asshown? A number line goes from negative 5 to positive 5. Point D is at negative 4 and point E is at positive 5. A line is drawn from point D to point E. What is the location of point F, which partitions the directed line segment from D to E into a 5:6 ratio? Negative one-eleventh One-eleventh Two-fifteenths Fifteen-halves. Plz help with this question Which diagram shows the parallelogram method for vector addition?. .I want a way to solve such a problem Given this graph of the function f(x) a) b) c) d) please a need help The __________________ is the tunnel that cuts through the external auditory meatus delivering sound to the ear drum or the _____________________. I NEED ANSWER NOW ASAP PLEASE ITS DUE IN 2 MINS!!!!! helllp meeeeeeeeeeeeeeee