Kinematics
29. A car starts from rest and attains a velocity
of 40 m/s in 20 s. It maintains this velocity
for 30 s and then comes to rest in 25 s.
Calculate
a) the acceleration of the car;
b) the deceleration of the car,
c) the total distance covered by the car.​

Answers

Answer 1

Answer:

a)

a = 2 [m/s^2]

b)

a = 1.6 [m/s^2]

c)

xt = 2100 [m]

Explanation:

In order to solve this problem we must use kinematics equations. But first we must identify what kind of movement is being studied.

a)

When the car moves from rest to 40 [m/s] by 20 [s], it has a uniformly accelerated movement, in this way we can calculate the acceleration by means of the following equation:

[tex]v_{f} = v_{i}+(a*t)[/tex]

where:

Vf = final velocity = 40 [m/s]

Vi = initial velocity = 0 (starting from rest)

a = acceleration [m/s^2]

t = time = 20 [s]

40 = 0 + (a*20)

a = 2 [m/s^2]

The distance can be calculates as follows:

[tex]v_{f} ^{2} = v_{i} ^{2}+(2*a*x)[/tex]

where:

x1 = distance [m]

40^2 = 0 + (2*2*x1)

x1 = 400 [m]

Now the car maintains its speed of 40 [m/s] for 30 seconds, we must calculate the distance x2 by means of the following equation, it is important to emphasize that this movement is at a constant speed.

v = x2/t2

where:

x2 = distance [m]

t2 = 30 [s]

x2 = 40*30

x2 = 1200 [m]

b)

Immediately after a change of speed occurs, such that the previous final speed becomes the initial speed, the new Final speed corresponds to zero, since the car stops completely.

[tex]v_{f} = v_{i}-a*t[/tex]

Note: the negative sign of the equation means that the car is stopping, i.e. slowing down.

0 = 40 - (a *25)

a = 40/25

a = 1.6 [m/s^2]

The distance can be calculates as follows:

[tex]v_{f} ^{2} = v_{i} ^{2} -2*a*x3\\[/tex]

0 = (40^2) - (2*1.6*x3)

x3 = 500 [m]

c)

Now we sum all the distances calculated:

xt = x1 + x2 + x3

xt = 400 + 1200 + 500

xt = 2100 [m]


Related Questions

Protons, electrons, and neutrons make up atoms and atoms make up A: Substances B: Matter C: Molecules D: Solids

Answers

Answer:

I think it's matter

Explanation:

Because everything is made of matter

Which of the following is NOT a vector?
A. Force
B. Acceleration
C. Mass
D. Displacement

Answers

Answer:

Explanation:

Mass is the only one of these that is not vector; everything else has both magnitude and direction.

Which has more inertia, a car with a mass of 900kg or a car with a mass of 1,500kg. Explain your answer.

Answers

Answer:

Which has more inertia - a car with a mass of 900kg or a car with a mass of 1500kg - explain. The bigger the mass - the larger the inertia but you need to exert more force to start the movement.

Explanation:

Consider two identical baseballs which start at the same location; their terminal speed at this location is 32 m/s. At t = 0s, Ball A is thrown straight up at m/s; Ball B is thrown at 16m/s 30.0° below the horizontal at 32 m/s. How do the magnitudes of the baseballs' accelerations32 2at t = 0s compare (do not neglect air resistance)?

Answers

Complete Question

The complete question is shown on the first uploaded image

Answer:

The correct option is  B

Explanation:

From the question we are told that

  The terminal  velocity of both balls is  [tex]v_t  =  32 \ m/s[/tex]

   The speed with which ball A is thrown up at t =0 s is  [tex]v__A}}  =  16\sqrt{2}[/tex]

   The speed with which ball B is thrown 30° below the horizontal  at t =0 s is  

[tex]v__{B}} =  32\sqrt{2}[/tex]

Generally the acceleration of ball A is (g i.e acceleration due gravity)given that it is thrown straight up  

Generally the vertical  acceleration of ball B is mathematically represented as

    [tex]a  = gcos (90 - 30)[/tex]

      [tex]a  = gcos (60)[/tex]

Generally the ratio of both acceleration is  

     [tex]\frac{a__{{A}}}{a__{{B}}}} =\frac{g}{gsin(60)}[/tex]

=> [tex]\frac{a__{{A}}}{a__{{B}}}} = \frac{1}{sin (60)}[/tex]

=>  [tex]\frac{a__{{A}}}{a__{{B}}}} = \frac{1}{\frac{\sqrt{3} }{2} }[/tex]

=>[tex]\frac{a__{{A}}}{a__{{B}}}} = \frac{2}{\sqrt{3} }[/tex]

Rationalizing

=> [tex]\frac{a__{{A}}}{a__{{B}}}} = \frac{2}{\sqrt{3} } *\frac{\sqrt{3} }{\sqrt{3} }[/tex]

=> [tex]\frac{a__{{A}}}{a__{{B}}}} = \frac{2 \sqrt{3} }{3}[/tex]

=>[tex]a__{B}} = \frac{2\sqrt{3} }{3} * a__{A}}[/tex]

Dan steps on the brakes in his toy car which causes a braking force of 700 N to the left.
a) If Dan’s car weighs 750 N, then what is the mass of Dan’s car?
b) What is the acceleration of Dan’s car?

Answers

Answer:

76.53 kg; 9.15 m/s² left.

Explanation:

Given the following data;

Weight of car = 750N

Applied force = 700N

a) To find mass

Weight can be defined as the force acting on a body or an object as a result of gravity.

Mathematically, [tex] Weight, W = mg[/tex]

We know acceleration due to gravity is equal to 9.8 m/s²

Substituting into the equation;

[tex] 750 = m*9.8[/tex]

[tex]Mass, m = \frac{750}{9.8}[/tex]

Mass, m = 76.53kg

b) To find the acceleration;

Force is given by the multiplication of mass and acceleration.

Mathematically, Force is;

[tex] F = ma[/tex]

Where;

F represents force.m represents the mass of an object.a represents acceleration.

Making acceleration (a) the subject, we have;

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

Substituting into the equation;

[tex]Acceleration (a) = \frac{700}{76.53}[/tex]

Acceleration (a) = 9.15 m/s² left.

When do we use Aerobic respiration & anaerobic respiration?

Answers

Answer:

the process by which organisms use oxygen to turn fuel, such as fats and sugars, into chemical energy. anaerobic respiration does not use oxygen. Respiration is used by all cells to turn fuel into energy that can be used to power cellular processes.

4. Calculate the momentum for each scenario:
a. .02 kg mass moving at 300 m/s
b. 2 kg mass moving at 40 m/s
c. 200 kg mass moving at 4 m/s

Answers

a) Answer:

Momentum = 6 kgm/s

Explanation:

Momentum = mass × velocity

Given that,

mass = 0.02 kg velocity = 300 m/s

Therefore, momentum = (0.02 × 300)kgm/s

Momentum = 6 kgm/s

b) Answer:

Momentum =80 kgm/s

Explanation:

Momentum = mass × velocity

Given that,

mass = 2 kg velocity = 40 m/s

Therefore, momentum = (40 × 2)kgm/s

Momentum = 80 kgm/s

c) Answer:

Momentum = 800 kgm/s

Explanation:

Momentum = mass × velocity

Given that,

mass = 200 kg velocity = 4 m/s

Therefore, momentum = (200 × 4)kgm/s

Momentum =800 kgm/s

A truck is traveling at a constant speed of 20 m/s through a school zone. At time t = 0 seconds, he passes a hidden police car that is at rest. Five seconds after the truck passes, the police car begins accelerating at a constant rate of 2 m/s in order to catch the truck.

Determine the time at which the speed of the truck is equal to the speed of the police car. Mark this time as t↓1. How will the positions of the police car and the truck compare when they have the same speed and why?​

Answers

Answer:

Let's define:

The position zero will be in the first point where the truck and police car meet. (So the initial position of both vehicles is zero)

Then, the position equation for the truck is:

T(t) = 20m/s*t

Where t is our variable, time in seconds.

Now, at t = 5s, the car starts accelerating.

Ac(t) = 2m/s^2                    for( t ≥ 5s)

For the velocity of the car, we must integrate that.

V(t) = (2m/s^2)*(t - 5)           for (t ≥ 5s)

Where i introduced a little change in the variable because the velocity of the car starts to increase for t larger than 5 seconds.

For the position of the car we integrate again.

C(t) = (1m/s)*(t - 5)^2            for (t ≥ 5s)

Now, let's answer the questions:

Determine the time at which the speed of the truck is equal to the speed of the police car.

Then we must have:

V(t) = (2m/s^2)*(t - 5)  = 20m/s.   (Remember that we only can use times requal or larger than 5 seconds).        

2m/s^2*t - 10m/s = 20m/s

2m/s^2*t = 30m/s

t = (30/2) s = 15s

The velocities of both vehicles will be the same after 15 seconds.

t1 = 15s

How the positions will compare at this time?

The easier thing will be to evaluate the position equation of each vehicle in this time:

T(15s) = 20m/s*15s = 300m

C(15s) = (1m/s^2)*(15s - 5s)^2 = (1m/s^2)*(10s)^2 = 100m.

Then we can see that the truck is 200m ahead of the car.

But remember that the police car is accelerating, so the velocity will keep increasing meaning that eventually, the car will catch the truck.

If a truck has a mass of 100 kg and
a velocity of 35 m/s, what is its
momentum?

Answers

Momentum = 100 x 35 = 3500 Kg m/s

Calculate: A model airplane has a mass of 3.2 kg. Its propeller pulls it forward with a force of 7.0 N. What is the airplane’s acceleration?

Answers

The airplanes acceleration is 2.1875

Plz help meeeeeeeeeeeeeeeeeee ahhhhhhhhh ❤️

Answers

Answer:

option 4

Explanation:

i just saw it from google

A rocket lifts vertically off the launching pad and reaches a final velocity of 450 m/s in 15 seconds. What is its acceleration

Answers

Answer:

The answer is 30 m/s²

Explanation:

The acceleration of an object given it's velocity and time taken can be found by using the formula

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

where

v is the velocity

t is the time

From the question

v = 450 m/s

t = 15 s

We have

[tex]a = \frac{450}{15} \\ [/tex]

We have the final answer as

30 m/s²

Hope this helps you

A warm-up is the exact same thing as a flexibility workout

True
False

Answers

false :) ✨ got you my g

Answer:

false

Explanation:

did the test this is correct

speed is the ______ an object travels over a given time period.

Answers

Answer: Rate

Explanation: Speed is the rate an object travels over a given time period.

Answer:

Distance

Explanation:

Speed is the distance an object travels over a given time period.

A student is able to run 5 meters in a time of 2 seconds. What is the average speed of this student in m/s?

Answers

Answer:

2.5

Explanation:

You have to find the unit rate, so 5 divided by 2 is 2.5.

PLS HELP. WORTH 25 POINTS
Explain how conduction, convection, and radiation drive the water cycle in Earth’s system.

Answers

Answer:

During the day, sunlight heats the ground, which in turn heats the air directly above it via conduction. At night, the ground cools and the heat flows from the warmer air directly above to the cooler ground via conduction.

Explanation:

Luck For You!

The process, in which conduction, convection, and radiation drive the water cycle in Earth’s system, is discussed in the answer.

What is water cycle?

The energy from the sun is what largely drives the water cycle. By evaporating water from the oceans, lakes, rivers, and even the soil, this solar energy powers the cycle. Through the process of transpiration, more water is transferred from plants to the atmosphere. Water droplets gradually acquire enough mass to fall back to Earth as precipitation as liquid water evaporates or transpires, forming clouds and water vapour.

The precipitation eventually transforms into runoff or groundwater and makes its way back into the surface reservoirs across a variety of periods. The hydrosphere currently contains the same amount of water as it has always contained in the Earth system since the water cycle is essentially a closed system.

Solar heat energy comes on earth's surface via radiation to the ponds, lakes, oceans, seas, rivers and other water resources and then the waterbodies get heated via conduction and evaporation happens. During evaporation time temperature water vapor goes to high altitude via convection of heat and cloud forms.

Learn more about water cycle here:

https://brainly.com/question/1151425

#SPJ2

Cacao beans arrive in a factory from the areas where they grew. At the factory, the best beans are sorted and put into bags. After quality-control workers check the bags, a large truck transports the cacao beans to a commercial chocolate-producing company. Which organelle plays a similar role inside a cell?
A. cytoplasm
B. Golgi body
C. mitochondrion
D. ribosome
E. vacuole

Answers

Answer:

B. Golgi body

Explanation:

The Golgi body is the region where proteins are modified, packaged, and transported to the appropriate location, usually outside of the cell.

The cytoplasm is the intracellular fluid/space, the mitochondrion produces energy, the ribosome produces proteins, and the vacuole is a storage organelle.    

The Answer is B , Because the golgi body stores stuff for later use.

hope this helps

One particle has a charge of 4.2 x 10-°C, while another particle has a charge
of 1.10 10-9 C. If the two particles are separated by 0.005 m, what is the
electromagnetic force between them? The equation for Coulomb's law is
F = kongs, and the constant, k, equals 9.00 x 10°Nm2/C2

Answers

The formula is F = 9x10^9 x q1 x q2 / r^2

Force = 9x10^9 x (4.2x10-9 x 1.1 x 10^-9) / 0.005^2

I hope you can do the maths on your calculator? Else ask me &!I will help.

Answer:

1.66*10^-3N

Explanation:

Help PLZ ;)

Which of the following statements is true about the force of gravity:
(A)The Force of gravity between two objects is directly related to the mass of the largest object.
(B)The force of gravity between two objects is directly related to the product of the object’s masses.
(C) The force of gravity between two objects is inversely related to the mass of the largest object.
(D) The force of gravity between two objects is inversely related to the product of the object’s masses.

Answers

Answer:

I believe it qould be A) The Force of gravity between two objects is directly related to the mass of the largest object.

Explanation:

A textbook that weighs 2 Newtons is lifted 4 meters. How much work is done on the book?

Answers

Answer:

The answer is 8 J

Explanation:

The work done by an object can be found by using the formula

workdone = weight × distance

From the question

weight = 2 N

distance = 4 m

We have

workdone = 2 × 4

We have the final answer as

8 J

Hope this helps you

what should you do if the exercise schedule you make for yourself is not working out well by midweek

Answers

Answer:

I will find a solution.

Explanation:

i will figure out the problem,then solve it

DO NOTWORKOUT WHAT AM I SUPPOSE TO SAYY

Brainliest ASAP!!

Solve the equation 4(s+5)=60

Answers

Answer:

s=10

Explanation:

4(s+5)=60

4s+20=60

4s=40

s=10

Give jesseocana the brainliest

The helium that fills a balloon is an example of which state of matter? (1 point)

a
Solid

b
Liquid

c
Gas

d
Plasma

Answers

Gas pls mark the brainleiest

which one of the following is a derived SI unit?
A.newton B.meter C.mole d.Kilogram ​

Answers

Answer:

Meter

Explanation:

I'd say meters, cause it's the SI unit of length,

which is a Derived Quantity.

how does a distance-time graph show you which direction the runner is moving? Use your own words and science vocabulary.

Please help will give brainliest to whoever does a 4 setence answer

Answers

In a distance time graph, when the x and y values are positive (in first quadrant), the runner is moving forward.

While, if the distance value ( in the y axis) is negative, the runner is moving backwards ( towards the start) .

Hope it helps :)

In the distance timeline, when the x and y values ​​are positive (in the first quadrant), the runner is moving forward. If the distance value (on the y-axis) is negative, the runner moves backwards (towards the start).

What is distance time graph?

A distance-time graph shows how far an object has travelled in a certain time. This is a simple line graph that plots observations by distance versus time.

 The distance is transferred to the Y axis.

Time is plotted on the X-axis.

The distance-time graph when we study the motion of bodies. If you set the distance and time of the movement of the object and transfer the same data to a rectangular graph, you will get a distance-time graph corresponding to the movement of the object.

To learn more about distance time graph, refer;

https://brainly.com/question/227462

#SPJ4

The slope of a distance vs. time graph is a measurement called
A. displacement
B. speed
C. correlation
D. velocity

Answers

Answer:

B. speed

Explanation:

im not sure hahahaha

binary ionic compounds are called salts. true or false

Answers

Answer:

True

Explanation:

APEX APPROVED

Answer: TRUE

Explanation:APΣX

A helicopter pulls upward by means of a rope on a 250 kg crate to lift it UNIFORMLY. What is the net force on the crate?

Answers

Answer:

The net force = 0

Explanation:

The given information includes;

The mass of the crate = 250 kg

The way the helicopter lifts the crate = Uniformly (constant rate (speed), no acceleration)

In order to pull the crate upwards, the helicopter has to provide a force equivalent to the weight of the crate keeping the helicopter on the ground.

The weight of the crate = The mass of the crate × The acceleration due gravity acting on the crate

The weight of the crate, [tex]F_w[/tex]↓ = 250 kg × 9.81 m/s² = 2,452.5 N

The force the helicopter should provide to just lift the crate, [tex]F_{(helicopter)}[/tex]↑ = The weight of the crate = 2,452.5 N

The net force, [tex]F_{(net)}[/tex] = [tex]F_{(helicopter)}[/tex]↑ - [tex]F_w[/tex]↓ = 2,452.5 N - 2,452.5 N = 0

The net force = 0.

TIME REMISE
01:57:34
As a person pushes a box across a floor, the energy from the person's moving arm is transferred to the box, and the
box and the floor become warm. During this process, what happens to energy?
O. It is increased.
O It is conserved,
O It is decreased.
O It is created.


Answers

Answer:

It is conserved

Explanation:

B .It's is conserved.

Which statement explains the similarity between momentum and kinetic energy of an object?
A. Both are inversely proportional to the mass and velocity of the object.
B. Both are directly proportional to the mass and velocity of the object.
C. Both are inversely proportional to force and displacement.
D. Momentum is directly proportional to the mass of the object and the square of the velocity of the object.
E. Kinetic energy is directly proportional to the mass of the object and the square of the velocity of the object.

Please help asap

Answers

Answer:

B. Both are directly proportional to the mass and velocity of the object.

Answer:

E. Kinetic energy is directly proportional to the mass of the object and the square of the velocity of the object.

Explanation:

I just took the test and it was right. Trust me on this one

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