A 700 kg car going 12 m/s speeds up to 30.6 m/s in 7 seconds. How much work was done to increase its speed?

Answers

Answer 1

Answer:

Approximately [tex]2.8 \times 10^{5} \; \rm J[/tex] (assuming that the car is moving on level ground, and that there is no friction to hinder the motion of the car.)

Explanation:

Formula for the kinetic energy, [tex]\rm KE[/tex], of an object of [tex]m[/tex] travelling at velocity [tex]v[/tex]:

[tex]\displaystyle \text{KE} = \frac{1}{2}\, m \cdot v^{2}[/tex].

Let [tex]v_1[/tex] and [tex]v_2[/tex] denote the velocity of this car before and after the acceleration.

Kinetic energy of this car before the acceleration:

[tex]\begin{aligned}\text{KE}_1 &= \frac{1}{2}\, m \cdot {v_1}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (12\; \rm m \cdot s^{-1})^{2} \\ &\approx 5.0 \times 10^{4}\; \rm J\end{aligned}[/tex].

Kinetic energy of this car after the acceleration:

[tex]\begin{aligned}\text{KE}_2 &= \frac{1}{2}\, m \cdot {v_2}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (30.6\; \rm m \cdot s^{-1})^{2} \\ &\approx 3.3\times 10^{6}\; \rm J\end{aligned}[/tex].

Assume that this car was travelling on level ground. Also assume that there is no friction to hinder the motion of this car. The work of the engine of this car  would be equal to the amount of [tex]\rm KE[/tex] that the car has gained:

[tex]\rm KE_2 - KE_1 \approx 2.8\times 10^{5}\; \rm J[/tex].


Related Questions

Luna and Angela are competitors in a running competition. Both are leading the race and enter at the same time the last 30 meters. Angela enters the final segment runnning at 4 m/s and "applies" an acceleration of 2 m/s2 while Luna enters the final segment at 3m/s but "applies " an acceleration of 3 m/s2. (a) Who finishes the race first? (Do the calculations) (b) Who is running faster at the end of the race?

Answers

Answer:

(a) Luna

(b) Luna

Explanation:

(b)

The final speed can be found by using the third equation of motion:

[tex]2as = v_f^2 - v_i^2\\[/tex]

where,

a = acceleration

s = distance covered

vf = final speed

vi = initial speed

For Angela:

a = 2 m/s²

s = 30 m

vi = 4 m/s

vf = v_fa

therefore,

[tex]2(2\ m/s^2)(30\ m) = (v_{fa})^2 - (4\ m/s)^2\\v_{fa}^2 = 120 m^2/s^2 + 16\ m^2/s^2\\v_{fa} = 11.66\ m/s\\[/tex]

For Luna:

a = 3 m/s²

s = 30 m

vi = 3 m/s

vf = v_fl

therefore,

[tex]2(3\ m/s^2)(30\ m) = (v_{fa})^2 - (3\ m/s)^2\\v_{fa}^2 = 180 m^2/s^2 + 9\ m^2/s^2\\v_{fa} = 13.74\ m/s\\[/tex]

Therefore, Luna will be running faster at the end of the race.

(b)

To calculate the time of completion we will use the first equation of motion:

[tex]v_f = v_i + at[/tex]

FOR ANGELA:

[tex]11.66\ m/s = 4\ m/s + (2\ m/s^2)t_a\\t_a = \frac{7.66\ m/s}{2\ m/s^2}\\\\t_a = 3.83\ s[/tex]

FOR LUNA:

[tex]13.74\ m/s = 3\ m/s + (3\ m/s^2)t_l\\t_l = \frac{10.74\ m/s}{3\ m/s^2}\\\\t_l = 3.58\ s[/tex]

Hence, LUNA finishes the race first.

Which has a higher momentum, a 3.5kg bowling ball that is rolling at 30
m/s or a 50 kg student moving at 1.75 m/s?

Answers

Answer:

The answer of this question

Explanation:

a3.5 kg blowing ball that is rolling at 30 m/s

How many degrees equal π in radians? How many revolutions (turns) equal π radians? ​

Answers

Answer:

It follows that the magnitude in radians of one complete revolution (360 degrees) is the length of the entire circumference divided by the radius, or 2πr / r, or 2π. Thus 2π radians is equal to 360 degrees, meaning that one radian is equal to 180/π ≈ 57.295779513082320876 degrees.

Explanation:

HELP
Which type of wave interaction is shown in the photo?
A. Interference
B. Refraction
C. Reflection
D. Diffraction

Answers

Answer: the answer is c (think bc im on that too)

Explanation:

The interference is a  type of wave interaction shown in the photo. Option A is correct.

What is the interference of waves?

The result of two or more wave trains flowing in opposite directions on a crossing or coinciding pathways. This phenomenon is known as the interference of waves.

The effect is the sum of the individual wave amplitudes at each site where more than one wave is present.

When two wave pulses are traveling along a string toward each other. They meet and the phenomenon is occur known as interference.

The interference is a  type of wave interaction shown in the photo

Hence option A is correct.

To learn more about the interference of waves refer to the link;

brainly.com/question/16098226

What force is caused by tiny collisions, called microwelds, on surfaces that
are stuck together?
A. heat
B. energy
C. air resistance
D. friction

Answers

Answer:

D. Friction

Explanation:

"Friction is caused by microwelds that form between two surfaces. Microwelds are stronger when the two surfaces are pushed together with a greater force." - ( Module 3 • Forces and Newton’s Laws) quoted

hope this helps and is right. p.s. i really need brainliest :)

Answer:

Friction

Explanation:

Took The Test

All waves travel through a

Group of answer choices

frequency

conductor

medium

wave

Answers

Conductor answer is conductor I’m sure

An 8.8-magnitude earthquake in Chile in 2010 killed more than 700 people. On January 12, 2010, a less powerful earthquake, measuring 7.0, killed more than 200,000 in Haiti. Why do you think this happened?

Answers

Answer:

The main reason for this is the engineering and technology driven building construction in Chile than in Haiti

Explanation:

The main reason for this is the engineering and technology driven building construction in Chile than in Haiti. Most of the buildings in Haiti do not fit in the building byelaws norms as most of them were constructed in a short period of time with less engineering and at cheaper rate. While building in Chile were built adhering to the building codes and byelaws.

The base of the building is Chile were separated from each other using the “base isolation” technology and the were also more flexible as compared to the buildings in Haiti.  

The skyscrapers in Chile were constructed in a way that they can float on the arrangements of ball bearings and padded cylinders

Ligaments are important because they provide joints with:
A lubrication.
B cushioning.
C stability.
D flexibility

Answers

Answer:

the answer is B. it's too easy

Two identical resistors connected in series have an equivalent resistance of 4 ohms. The same two resistors, when connected in parallel, have an equivalent resistance of:

Answers

Answer:

1 ohm

Explanation:

since there are two identical resistors, one resistor will be

R = [tex]\frac{4}{2}[/tex] =2ohm [ proven as in series [tex]R_{e} = 2 + 2 = 4ohm[/tex] ]

to calculate the equivalent resistance when in parallel:

[tex]\frac{1}{R_{e} } = \frac{1}{R_{1} } + \frac{1}{R_{2}}[/tex]

so,

[tex]\frac{1}{R_{e} } = \frac{1}{2} + \frac{1}{2}[/tex]

[tex]R_{e} = 1ohm[/tex]

Two identical resistors connected in series have an equivalent resistance of 4 ohms. The same two resistors, when connected in parallel, have an equivalent resistance of 1 ohm.

What is ohm?

In a parallel circuit, voltage is thee same across each component in the circuit. The sum of the currents through each path is equal to the current from the source. However, the resistance cannot be added directly. It is calculated as:

1/Rt = 1/R1 + 1/R2 + 1/R3 1/Rt = 1/6.8 + 1/9.0 + 1/15

Rt = 3.08 ohms.

When resistors are connected in parallel, the equivalent resistance R will be less than the least resistance.

1/R = 1/R1 + 1/R2 + 1/R3 + 1/R4 + 1/R5

Since the 5 resistors are 10 ohms each, substitute them in to the formula

1/R = 1/10 + 1/10 +1/10 + 1/10 + 1/10

The LCM = 10

1/R = 5/10

Reciprocate both sides

R = 10/5 = 2 ohms

Therefore, Two identical resistors connected in series have an equivalent resistance of 4 ohms. The same two resistors, when connected in parallel, have an equivalent resistance of 1 ohm.

Learn more about equivalent resistance on:

https://brainly.com/question/13606415

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How many cups of water should you drink in a day?

Answers

Answer:

about 2.7liters for women and 3.7liters for men

Explanation:

The reason Senators are in office for 6 years is...

No links pls or I’m reporting you :)

1) To separate Senators from the whims of the
general public.

2) to save money in elections

3) Because Senators are required to be older
than representatives

Answers

I think it’s answer 1 to separate senators fr om the whims or the general public

eating disorder Symptoms

Answers

Answer:

some symptoms can be lack of energy, and dizziness.

Explanation:

Utility companies charge by the kilowatt-hour. The number of kilowatt-hours used equals the number of kilowatts multiplied by the number of hours an electrical device was used. How long would it take for a 50-watt fan to use 1 kilowatt-hour of electricity? (Hint: 50 watts = 0.05 kilowatts.)

Answers

Answer:

t = 3 minutes

Explanation:

Given that,

Power of fan, P = 50 W

Energy used, E = 1 kWh

We know that,

Energy = Power/time

As, 50 watts = 0.05 kilowatts

So,

[tex]t=\dfrac{P}{E}\\\\t=\dfrac{0.05\ kW}{1\ kWh}\\\\t=0.05\ h[/tex]

or

t = 3 min

So, the required time is equal to 3 minutes.

True or False: There are many different types of leukocytes.


True


False

Answers



the answer is a.) true


Which of the following regions of the EM epxtrum has the highest
frequency?

1) x rays
2) microwaves
3) infrared light
4) ultraviolet light

Answers

Answer:

1) x rays

Explanation:

Honestly Gamma rays has the Highest frequency, but in your options, gamma rays is not among, so x rays has the highest frequency among your options.

by Manshow

Answer:

The answer is (X-rays)

number 1

Q1) Calculate the gravitational force between two large trucks, each with a mass of 6500 kg, if
they are parked next to each other separated by a distance of 0.5 m Ignore all other
gravitational forces.

Answers

Answer:

F = 0.0112 N

Explanation:

Given that,

Masses, [tex]m_1=m_2=6500\ kg[/tex]

The distance between masses, d = 0.5 m

We need to find the gravitational force between two large trucks. The formula for the gravitational forces is given by :

[tex]F=G\dfrac{m^2}{r^2}\\\\F=6.67\times 10^{-11}\times \dfrac{6500^2}{(0.5)^2}\\\\F=0.0112\ N[/tex]

So, the required force between masses is equal to 0.0112 N.

What is the speed of a wave in (m/s) with a 5 meter wavelength and a period of 20 seconds?

Answers

Answer: 0.25 m/s

Explanation:  Speed = wavelengt · frequency  

v = λf   and frequency is 1/period  f = 1/T

Then v = λ/T = 5 m / 20 s = 0.25 m/s

As Jack pulls his wagon down the street it moves faster and faster. Jill, sitting a few meters ahead on the sidewalk, wants to slow Jack's wagon down so that it travels with a constant speed. How can Jill accomplish her goal? A) Push the wagon with a force greater than Jack. B) Push Jack away from the wagon so that he is no longer pulling it. C) Pull on the wagon in the opposite direction with twice Jack's force. D) Push the wagon in the opposite direction at a constant force less than Jack.

Answers

Answer:

The correct answer is NONE the two forces must be equal and of opposite direction, the closest answer is D

Explanation:

In this exercise it is indicated that Jack pushes a car, it is desired that Jill pushes the car so that the speed is constant

take as positive the direction of Jack's thrust

             F_jack - F_jill = 0

              F_jill = F_jack

therefore the push of the two must be equal and Jill's push must have the opposite direction to Jack's push.

The correct answer is NONE the two forces must be equal and of opposite direction, the closest answer is D

When a 6 Ω resistor is connected across the terminals of a 3 V battery, the number of coulombs passing through the resistor per second is

Answers

Answer:

Given that - R = 6 ohm

V = 3 volt

n = ?

so by ohms law , V = I X R

I = V \ R = 3 \ 6 = 0.5 A

we know that I = Q / T here t is 1 sec

Q = I X T = 0.5 X 1 = 0.5 C

By the law of quantization ,

Q = n x e

n = Q / e = 0.5 / 1.6 x 10 ^-19

n = 0.3125 x 10^19

hoped so u got the answer mark me as brainellist :)

Answer:

0.5/1.6×10^-19

Explanation:

formula for current is v

I R

3/6=0.5

charge if found by the product of current and time which is one second

0.5×1 =0.5

deficiency of n=no of charges×charge of electrons

0.5/1.6×10^-19

The conversion of sugar to energy in the presence of oxygen is
A.
respiration
B.
protein synthesis
C.
binary fission
D.
photosynthesis

Answers

Answer:

A. respiration.

Explanation:

Cellular respiration can be defined as a series of metabolic reactions that typically occur in cells so as to produce energy in the form of adenosine triphosphate (ATP). During cellular respiration, high energy intermediates are created that can then be oxidized to make adenosine triphosphate (ATP). Therefore, the intermediary products are produced at the glycolysis and citric acid cycle stage.

Additionally, mitochondria provides all the energy required in the cell by transforming energy forms through series of chemical reactions; breaking down of glucose into Adenosine Triphosphate (ATP) used for providing energy for cellular activities in the body of living organisms.

Basically, oxygen goes into the body of a living organism such as plants, humans and animals when they breathe while glucose is absorbed by the body when they eat.

Hence, the conversion of sugar to energy in the presence of oxygen is respiration.

The smaller the mass of an object, the _____ its inertia

Answers

Answer:

larger

Explanation:

just trust me

The smaller the mass of an object, the smaller its inertia, because the inertia of any object is directly proportional to the mass of the object

What is inertia?

The ability of an object to resist changes in motion is known as inertia. The amount of inertia is directly related to an object's mass; in fact, as we frequently observe, the heavier an object is, the harder it is to change its direction of motion.

A straightforward illustration: While it is relatively simple to stop a tennis ball that has been thrown in our direction, we are aware that it is more difficult to stop a large truck that is moving in the same direction at the same speed. This is because the truck has a much higher mass than the tennis ball and a higher moment of inertia. As a result, inertia rises as mass does.

Since the inertia of any object is directly proportional to its mass, the smaller its mass, the less inertia it will have.

Learn more about Inertia from here

https://brainly.com/question/1358512

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2 ways in which the effects of friction can be minimised in the experiment​

Answers

Answer:

Friction can be minimized by using lubricants like oil and grease and by using ball bearing between machine parts. A substance that is introduced between two surfaces in contact, to reduce friction, is called a lubricant. Fluid friction can be minimized by giving suitable shapes to the objects moving in the fluids.

Explanation:

hope it helps

How are radio waves modified to send information?

Answers

Answer:

Radio waves can be modified by their amplitude or frequency in order to transmit sound or data.

Explanation:

Hope this helped!!!

Which color of light comes from a greater energy transition?
1. Red 2. Yellow 3. Green 4. Blue

Answers

Answer:

D.) Blue

Explanation:

because Blue is a higher frequency and therefore corresponds to a higher energy level transition.

I hope this helped you :)

A 905 kg test car travels around a 3.25 km circular track. if the magnitude of the force that maintains the car's circular motion is 2140 N, what is the car's tangential speed?

Answers

Link provided in other answer is a SCAM, don’t click on the link !!!!

what are the objectives of the tourist for visiting Nepal write in points​

Answers

Answer:

The objectives of the tourist for visiting Nepal are .

It is naturally decorative .Highest mountain ️ of the world mt.everest is situated in Nepal .many rivers are there for rafting .different types of land and climate can be found .many historical , religious and cultural site are present here to visit .

hope it is helpful to you ☺️

When setting your schedule, it is sometimes necessary to tell people "No." Please select the best answer from the choices provided. t or f​

Answers

Answer:

True Edg2020

Explanation:

Answer: true

Explanation:

because I say so :P

Consider again the civilization described in the previous question. (They live on a planet orbiting 10 AU from a close binary star system that consists of a 15 MSun red giant star and a 10 MSun black hole surrounded by an accretion disk.) Through a bizarre (and scientifically unexplainable) fluctuation in the space-time continuum, a copy of a book from that civilization arrives on your desk; it is entitled Iguoonos: How We Evolved. In the first chapter, you learn that these beings evolved from organisms that lived 5 billion years ago. Which of the following statements should you expect to find as you continue to read this book?
A. Their immediate ancestors were chimpanzees.
B. As a result of traumatic experiences to their evolutionary ancestors, they dislike television.
C. They evolved on a different planet in a different star system, and moved to their current location.
D. They evolved from primitive wormlike creatures that had 13 legs, 4 eyes, and bald heads, thus explaining why such critters are now considered a spectacular delicacy.
E. They believe that the presence of two stars in their system was critical to their evolution.

Answers

Fysbsts dydbdysj dudgts offhand fidydh jdgdhd

a battery causes a current of 2.0 A to flow through a lamp. the power used by the lamp is 12 watts. what is the voltage (i asked this before and never got the answer, i need the answer soon)

Answers

Answer: 6V

Explanation:

Boxers wear gloves that are padded to lessen the force of a punch. Calculate the force exerted by a boxing glove on an opponent's face, if the glove and face compress 8.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. Give your answer in Newtons, do not include the unit in your answer.

Answers

Answer:

F = 4117.64

Explanation:

First, we will calculate the acceleration of the hand, by using the third equation of motion:

[tex]2as = v_f^2 - v_i^2\\[/tex]

where,

a = acceleration = ?

s = distance covered = compression = 8.5 cm = 0.085 m

vf = final speed = 0 m/s

vi = iniial speed = 10 m/s

Therefore,

[tex]2a(0.085\ m) = (0\ m/s)^2-(10\ m/s)^2\\a = - 588.23\ m/s^2[/tex]

negative sign hows deceleration.

Now, we will calculate the force exerted by the hand:

[tex]F = ma = (7\ kg)(588.23\ m/s^2)\\[/tex]

F = 4117.64 N

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