A car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.51 m/s2 for t1 = 20 s. At that point the driver notices a tree limb that has fallen on the road and brakes hard for t2 = 5 s with a constant acceleration of a2 = -5.03 m/s2. Write an expression for the car's speed just before braking.

Answers

Answer 1

Answer:

v =  1.51t and v = 30.2 m/s just before braking

Explanation:

Using v = u + at where u = initial velocity of car = 0 m/s (since it starts from rest), a = a1 = acceleration before braking = 1.51 m/s², t = t1 = time before braking = 20s and v = speed of car before braking.

Substituting the values of the variables into the equation, we have

v = u + at

v = 0 m/s + 1.51 m/s²t

v =  1.51t and its value after 20 s is

v = 1.51 × 20

v = 30.2 m/s which is the value just before braking.


Related Questions

Water is considered to be

Answers

Answer: the thing that brings you life- h2o- idrk the question but if this helps your welcome ^-^have a good day

Explanation:

what is the amount of time for one cycle to to occur

Answers

[tex] \\ [/tex]365 DAYS

Period, being a time, is measured in units of time such as seconds, hours, days or years. The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle

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Hope It Helps!

Two magnets are held apart. Once released, the South Pole of one magnet moves toward the North Pole of another magnet until the magnets collide. How does the graph reflect the changes in energy that occur?

Answers

Answer:

Kinetic energy and velocity are at zero when the magnets are held apart, and both increase rapidly when they are released and move together. Energy stored in the magnetic field decreases.

Explanation:

easy

The increase in the kinetic energy occurs when both magnets are released.

Change in energy occurs between two magnets

The kinetic energy and velocity are at zero when the magnets are held apart from one another at a certain distance  but the kinetic energy increases when they are released and move together so we can conclude that the increase in the kinetic energy occurs when both magnets are released.

Learn more about magnets here: https://brainly.com/question/14997726

A driver pushes on a car with a force of 8000 N for 15 seconds but is unable to move it. How much work is done

Answers

Answer:

the work done is zero.

Explanation:

Given;

applied force, F = 8000 N

time of force application, t = 15 s

Work done is given as the product of force and displacement. Since the car is unable to move, then the displacement is zero and the work done is zero.

Work done = Force x displacement

Work done = 8000 N x 0

Work done = 0

Therefore, the work done is zero.

why would a bouncing ball eventually stop bouncing?

Answers

The bouncing ball stops bouncing because of mainly three factors :
1. Friction
2. Gravity
3. Decrease in potential energy

The force of gravity pulls it down, and as the ball falls, its potential energy is converted to kinetic energy. When you drop the ball from a certain height, the potential difference is at its extreme point. When the ball hits the ground, the potential energy naturally decreases, which stops the ball from bouncing after a while.

What is a real world example of the Law of Conservation of Momentum?

Answers

Answer:

The thrust that you feel at the time of firing is one of the real-life example of the conseriation nomentum

what is refractive index ? ​

Answers

refractive index of a material is a dimensionless number that describes how fast light travels through the material

Explanation:

Refractive Index is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density. The refractive index variable is most commonly symbolized by the letter ‘n’ or n’ in a descriptive text and mathematical equations.

Some one plz help me and I will give you brainliest plz

Answers

It’s more in the 23N range.

Encuentra la magnitud y dirección de la suma de los siguientes vectores: A= 7m al noreste B= 12m 50° al oeste del norte

Answers

Pon foto de lo que te muestra así no se puede contestar xd

A motorist is driving at a constant velocity of 28.0 m/s when he decides to pass a car is in front of him. He accelerates at a rate 2.50 m/s2 for 3.00 seconds while passing the car. What is his velocity at the end of the 3.00 seconds?

Answers

Answer:

Final velocity, V = 35.5m/s

Explanation:

Given the following data;

Initial velocity = 28m/s

Acceleration = 2.5m/s²

Time = 3 seconds

To find the final velocity, we would use the first equation of motion

V = U + at

Where;

V is the final velocity measured in m/s.

U is the initial velocity measured in m/s.

a is the acceleration measured in m/s².

t is the time measured in seconds.

Substituting into the equation, we have;

V = 28 + 2.5*3

V = 28 + 7.5

Final velocity, V = 35.5m/s

how does an ice cube cause hot coffee to become cool and through what heat transfer

Answers

an ice cube causes hot coffee to become cool because the amount of coldness contrasts the hot coffee to make it a little cooler

prove that total mechanical energy is always constant​

Answers

Explanation:

We know that the overall mechanical energy of a device stabilizes in the absence of any external force. We know that that the total of potential and kinetic of the freely velocity vector remains same. ,So mechanical energy of a body, underneath gravitation, remains constant.

Which are electromagnetic waves? Check all that apply.

earthquake waves
infrared waves
ocean waves
radio waves
ultraviolet waves

Answers

Answer:

infrared waves

radio waves

ultraviolet waves

Explanation:

Radio waves are used for communication such as television and radio.

Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark.

Ultraviolet radiation can kill bacteria that are present in water - this sterilises the water and makes it safe to drink.

Answer:

infrared waves

radio waves

ultraviolet waves

Explanation:

Radio waves are used for communication such as television and radio.

Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark.

Ultraviolet radiation can kill bacteria that are present in water - this sterilises the water and makes it safe to drink.

I NEED HELP ASAP!!

What is the path of a projectile (in the absence of friction)?
a.
a wavy line
b.
a parabola
c.
a hyperbola
d.
Projectiles do not follow a predictable path.


Please select the best answer from the choices provided

A
B
C
D

Answers

Answer:

Your answer should be B. a parabola.

Explanation:

The path of the projectile in the absence of friction is a parabola. Therefore, option (b) is correct.

What is the projectile motion?

Projectile motion can be described as a form of motion experienced by a projectile that is projected near the surface of the earth and moves along a curved path under the action of gravity. This curved path is to be a parabola, but may also be a straight line in special cases when the projectile is thrown directly upwards.

The study of such motions is known as ballistics and the only force that is actively exerted is gravity, which acts downward, thus giving the object a downward acceleration toward the Earth’s center of mass.

No external force is required to maintain the horizontal velocity component of the object's motion because of the object's inertia. Other forces, such as aerodynamic drag or internal propulsion need additional analysis.

Therefore, the path of an object or projectile is generally parabola in the absence of friction.

Learn more about projectile motion, here:

https://brainly.com/question/11049671

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Heat is an exchange of internal energy from one system to another due to
OA.
one system being liquid and the other being solid.
OB.
the systems having the same temperature.
OC.
one system being gas and the other being solid.
OD
a temperature difference between the systems.

Answers

Answer:

OD

Explanation:

2 bodies should have different temperatures for energy to be transferred

Two charges separated by one meter exert a 9 N force on each other. If the charges are pushed to a 3 meter separation, the force on each charge will be 3 N.
True or False?

Answers

Answer:

False

Explanation:

The formula of force that exists between two charges is expressed as;

F = kq1q2/r²

If two charges separated by one meter exert a 9 N force on each other, the;

9 = kq1q2/1²

9 = kq1q2 ..... 1

If the charges are pushed to a 3 meter separation, then;

F =  kq1q2/3²

F =  kq1q2/9 .... 2

Divide both equations;

9/F = (kq1q2)/ kq1q2/9

9/F =  kq1q2 * 9/ kq1q2

9/F = 9

F = 9/9

F = 1N

Hence if the charges are pushed to a 3 meter separation, then the force on EACH charge will be 1N. Hence the answer is False

What is the charge of an electron and charge of neutron

Answers

Answer:

The charge of a neutron is 0  

The charge of an electron is -1

Explanation:

Answer:

The charge of Neutrons is: 0

The charge of Electrons is: -1

Explanation:

Neutrons are uncharged and Electrons are negatively charged. The negative charge of one electron balances the positive charge of one proton. Both protons and neutrons have a mass of 1, while electrons have almost no mass.

What unit of time on Earth is based on the revolution of the Earth around the Sun?
A.
day
B.
hour
C.
year
D.
month

Answers

C.) Year

i hope this helped! please mark me as brainliest and 5 stars >:)

Answer:

I believe it's C. Year.

Explanation:

Hope this helps! ^^

Milk being heated on top of a stove will do what?

Group of answer choices

Expand

Contract

Stay the same

Answers

The answer would be Expand because when a liquid is heated the molecules expand

Hope this helps

Have a great day/night

¿Qué trabajo realiza una carreta que contiene una de masa 800 lb de cemento si se desplaza 100 m por un suelo nivelado?

Answers

Answer:

Ver respuesta en el procedimiento

Explanation:

En este caso, necesitamos la expresión que nos permite hallar el Trabajo realizado por un objeto a través de una distancia dada. Esa expresión es:

W = F * x   (1)

Donde:

W: Trabajo en Joules (J)

F: Fuerza en Newton (N)

x: Distancia o radio en metros (m)

En este caso, solo tenemos una masa de 800 lb, y la distancia que se esta recorriendo. No tenemos ningún dato adicional que nos diga si por ejemplo, es empujado por una persona o parecido, solo los datos de la masa que lleva la carreta. Por lo tanto, la única fuerza que podemos asumir se está ejerciendo, sería la fuerza del peso del objeto que se calcula así:

P = mg   (2)

Donde:

g: aceleración de gravedad (9,8 m/s²)

Ahora bien si reemplazamos (2) en (1) nos queda:

W = mgx  (3)

Y antes de realizar el cálculo debemos convertir la unidad de masa en libra a kilogramo, usando la siguiente conversión:  1 lb -----> 0,454 kg por tanto:

m = 800 * 0,454 = 363.2 kg

Ahora podemos usar (3) y calcular el trabajo:

W = 363,2 * 9,8 * 100

W = 355936 J o simplemente 355,936 kJ

Espero te sirva.

PD: También puedes usar el valor de gravedad como 10 m/s² y tendrás un resultado de 363200 J o 363,2 kJ.

????????????????what’s the answer

Answers

Answer:

I don't know what do u. mean

3. A 6 kg block moving to the right at 4 m/s collides with and sticks to a stationary block of unknown mass. If the two blocks move off to the right at 3 m/s, what was the mass of the stationary block?

Answers

Answer: 2kg

Explanation:

This problem is a textbook conservation of momentum problem. The intial momentum is equal to the final momentum. For the initial state of each block, only the first one was moving. Then they both combine to move together.

Pi = Pf

with p = mv

(6kg)*(4m/s) = (6kg+xkg)(3m/s)

Let x equal the unknown mass of block 2

24 = 18 + 3x

6 = 3x

x = 2kg

A roller coaster of mass 2000 kg is rolling down a track with an
instantaneous speed 10 m/s. What is its kinetic energy in Joules?

Answers

Answer: 100k Joules

Explanation:

a man shoveling snow clears his front step using 200 joules in 100 seconds, how much power did he use

2 watts
20,000 watts
100 watts
300 watts​

Answers

Answer:

2 watts

Explanation:

2 watts

200 J divided by 100 S = 2

You push on 35 N object for 3 seconds. Find work.​

Answers

Sorry I don’t know the answer
Is it more to the Question

i need help asap

The downward force of gravity causes _______ displacement of an object, but the force of gravity does not affect the ________ component of motion.

a.

negative, horizontal

c.

negative, vertical

b.

positive, vertical

d.

None of the above.



Please select the best answer from the choices provided


A

B

C

D

Answers

Answer:

The correct answer is A

Explanation:

I hope it helps ❤❤

Example of kinetic to potential ? And how the energy is changing forms???? Please help

Answers

Answer:

A ball when from moving to stoping

Explanation:

Kinetic = energy of motion

Potential = energy stored

When you roll a ball on the ground, it gains kinetic energy, but then the ball starts to slow down until it stops and it remains at rest which means it's at potential energy. It went from moving (kinetic) to stoping (potential)

Hope this helped!

Have a supercalifragilisticexpialidocious day!

In zero gravity, do the laws of motion still apply? No, objects cannot
be in
motion in
space because
there is no gravity.
No, if you do not
have gravity you
have no motion.
Yes, objects in
motion in space do
not have inertia.
Yes, objects in motio
in space tend to stay
motion unless acte
upon by an outside
force.

Answers

Answer:

Im pretty sure that it applys

I’m pretty sure it does hope this helps you

why do the planets stay in their orbit around the sun?

Answers

Answer:

The Sun's gravity constantly pulls on the planets, preventing them from leaving their orbit and the solar system. The forward motion of the planets prevents the Sun's gravity from pulling planets straight into it.

Explanation:

Which is considered a dark green vegetable?
A.
Carrots
B.
Broccoli
C.
Squash
D.
Green peas

Answers

Answer:

Broccoli

Explanation:

Answer:

b. broccoli

Explanation:

took the quiz

hope this helps

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