A 1500 kg sedan goes through a wide intersection traveling from north to south when it is hit by a 2500 kg SUV traveling from east to west. The two cars become enmeshed due to the impact and slide as one thereafter. On-the-scene measurements show that the coefficient of kinetic friction between the tires of these cars and the pavement is 0.750, and the cars slide to a halt at a point 5.48 m west and 6.37 in south of the impact point. How fast was sedan traveling just before the collision? How fast was SUV traveling just before the collision?

Answers

Answer 1

Answer:

v = 19.33 m / s   South

Explanation:

To solve this exercise we must use the conservation of momentum, for which we must define a system formed by the two cars, therefore the forces during the collision are internal and therefore the moment is conserved.

Since it is a vector quantity, we are going to work on each axis, the x axis is in the East-West direction

initial instant. Before the crash

        p₀ = m 0 + M v₂ₓ

final instant. Right after the crash

        p_f = (m + M) vₓ

        p₀ = 0_pf

        M v₂ₓ = (m + M) vₓ

In this case m is the mass of the car and M the mass of the SUV

        vₓ = [tex]\frac{M}{m+My}[/tex]  v₂ₓ            (1)

in the Y axis (North - South direction)

initial instant

       p₀ = m v_{1y} + M 0

final moment

       p_f = (m + M) v_y

       p₀ = p_f

       m v_{1y} + M 0 = (m + M) v_y

       v_y = [tex]\frac{m}{m+M} \ v_{1y}[/tex]       (2)

With these speeds we can use the relationship between work and the variation of kinetic energy, in this part the two cars are already united.

         W = ΔK

friction force work is

         W = - fr d

the friction force is described by the equation

         fr = μ N

Newton's second law

         N-W = 0

         N = W

         

we substitute

         W = - μ (m + M) g d

as the car stops the final kinetic energy is zero and

the initial kinetic energy is

         K₀ = ½ (m + M) v²

we substitute

         - μ (m + M) g d = 0 - ½ (m + M) v²

            μ g d = ½ v²

            v² = 2 μ g d

the distance traveled can be found with the Pythagorean theorem

        d = [tex]\sqrt{x^2+y^2}[/tex]

        d = [tex]\sqrt{5.48^2 + 6.37^2}[/tex]

        d = 8.40 m

let's calculate the speed

         v² = 2 0.75 9.8 8.40

         v = √123.48

         v = 11.11 m / s

this velocity is in the direction of motion so we can use trigonometry to find the angles

          tan θ = y / x

          θ = tan⁻¹ y / x

          θ = tan⁻¹ (-5.48 / -6.37)

          θ = 40.7º

Since the two magnitudes are negative, this angle is in the third quadrant, measured from the positive side of the x-axis in a counterclockwise direction.

          θ'= 180 + 40.7

          θ’= 220.7º

In the exercise they indicate the the sedan moves in the y-axis, therefore

          sin θ'= v_y / v

          v_y = v sin 220.7

          v_y = 11.11 sin 220.7

          v_y = -7.25 m / s

the negative sign indicates that it is moving south

To find the speed we substitute in equation 2

          v_y = [tex]\frac{m}{m+M} \ v_{1y}[/tex]

          v_{1y} = v_ y   [tex]\frac{m+M}{m}[/tex]

           

let's calculate

         v_{1y} = -7.25    [tex]\frac{1500+2500}{1500}[/tex]

         v_{1y} = - 19.33 m/s

therefore the speed of the sedan is v = 19.33 m / s with a direction towards the South


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Answer:

Let's explain this briefly.

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Once we have a complete change of phase, the temperature can increase again, and now we will have liquid water.

If we keep increasing the temperature we will see this happen again, when we have the transition from liquid to gas.

(and a similar thing happen when we have a material in a given phase and we remove heat from the material).

In the images we can see the different changes of phase of water.

1) In the first image we can see the circle in a part where the temperature is constant, so the temperature does not change in this part, which means that there is a change of phase happening.

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3) Here we want to know what the x-axis represents, this should rerpesent the energy that is being given to the material (so in some parts we see that the temperature increases and in other parts we see that the material changes of phase)

Then here the correct option is heat over time.

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Then the correct option is -210°C (The last option)

magnetism is an example of:
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Answers

Answer:

The answer is Non contract force

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Answers

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Answers

Answer:

14 m/s^2

Explanation:

We have to use the equation F=ma because the question is a Newton's second law question.

First, list known values

F (force) = 70 N

m (mass) = 5 kg

a (acceleration) = ? (we have to solve for this)

Second, plug in known values into equation.

F=ma

70=5a

Third, solve. To solve this all you have to do is divide both sides by 5

70/5=5/5a

Fourth, your answer will be 14 meters per second squared  (m/s^2)

I hope this answer helps and have a great day!

Newton discovered that sunlight was composed of colors.


True or False

Answers

Answer:

True

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Explanation:

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Answer:

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Answer:

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Answers

Answer:

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Explanation:

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The mass of the hanging mass is m and the mass of the cart is M . You can assume that the floor over which the mass hangs has been chosen as the zero point of gravitational potential energy. If the hanging mass is at a height h above the floor, and has not yet been released, what type(s) of energy is/are present in the system

Answers

Answer:

Gravitational Potential Energy

Explanation:

Gravitational potential energy is energy an object possesses because of its position in a gravitational field  (Hyper Physics). The potential energy is the energy that is stored in an object due to its position relative to some zero position(Physics Classroom).

For a body held at a height (h), the gravitational potential energy is capable to do work once the object is released from the height (h)

HELP URGENT WILL GIVE BRAINLIEST

Answers

i think it’s B. I just makes most sense in my opinion.

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Answers

Answer:

12 m/s²

Explanation:

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a = (1300-1240) / 5

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Answer:

[tex]\boxed{\text{\sf \Large 12 m/s^2 $}}[/tex]

Explanation:

Use acceleration formula

[tex]\displaystyle \text{$ \sf Acceleration=\frac{Change \ in\ velocity}{Time \ taken} $}[/tex]

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Answers

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answer: A) a car which is slowing down is accelerating

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Answer:

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Answers

Answer:

[tex]a=2.14\ m/s^2[/tex]

Explanation:

Force in upward direction = 45 N

Force in right side = 60 N

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Net force on the object is given by :

[tex]F=\sqrt{45^2+60^2} \\F=75\ N[/tex]

We know that,

F = ma

Where

a is acceleration of the object

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So, the acceleration of the object is [tex]2.14\ m/s^2[/tex].

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Answers

Answer:

Explanation:

The acceleration of gravity is 9.8m/s^2.

So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.

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Answers

Answer:

directly proportional

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Answers

Answer:

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Required:
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Answers

Answer:

h = 40.37 m

Explanation:

We will apply the law of conservation of energy to the skier in this case, as follows:

[tex]Energy\ of\ skier\ at\ the\ gate = Energy\ of\ Skier\ at\ the\ end\\P.E + K.E_{i} = K.E_{f} - W_{friction}\\mgh + \frac{1}{2}mv_{i}^2 = \frac{1}{2}mv_{f}^2 - W_{friction}\\\\mgh = \frac{1}{2}m(v_{f}^2-v_{i}^2) - W_{friction}[/tex]

where,

m = mass of skier = 77 kg

g = acceleration due to gravity = 9.81 m/s²

vf = final speed = 30 m/s

vi = initial speed = 2 m/s

W_friction = Work done by friction and air resistance = 4000 J

Therefore,

[tex](77\ kg)(9.81\ m/s^2)h = \frac{1}{2}(77\ kg)[(30\ m/s)^2-(2\ m/s)^2] - 4000\ J\\\\h = \frac{34496\ J - 4000\ J}{755.37\ N}\\\\[/tex]

h = 40.37 m

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2.1/4 as much
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Answers

Answer:

1/4 as much

Explanation:

I don't know the explanation

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inertia
weight
direction
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Answers

Answer:

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Answer:

We answer that before but I forgot

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Answers

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Answer:

B) Blinking .

Explanation:

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Answers

Answer:

wnd change

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HELP ASAP PLS


A) there is no gravitational potential energy between them



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D) the amount of gravitational potential energy decreases.

Answers

Answer:

D

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forecasted for the miscommunication between range and the other day

An open pipe is 1.42 m long.
What is the third harmonic
frequency that it produces?
(Speed of sound = 343 m/s)
(Unit = Hz)
please help me guys

Answers

Answer:

f(3) = 362.32 Hz

Explanation:

the formula of frequency of open pipe is

f(n) = (n+1)v/2L

n = 0,1,2,3,... (the order)

0 for the first

1 for the second

v = speed of sound

L = the lenght of pipe

f(3) = (2+1) * 343 / 2 * 1,42

f(3) = 3 * 343 / 2.84

f(3) = 362.324 Hz (or you can write 362.32 Hz

Answer: 362.32

Explanation:

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