A car is driving 12m/sec, has to stop suddenly because a pedestrian dashes out in front of the car. If the coefficient of kinetic friction between the tires and parking lot is ∪=60

what is the time, after the breaks are applied, before the car comes to a stop? Sketch the velocity time graph for the car's motion from the instant the breaks are applied until the car comes to a stop.

Hi there!

With the work-energy theorem for oscillating springs:

ME = KE + PE

[tex]ME = \frac{1}{2}mv^2 + \frac{1}{2}kx^2[/tex]

Where:

m = mass (kg)

v = velocity (m/s)

k = Spring Constant (N/m)

x = displacement from equilibrium (m)

If the object is at the equilibrium position, there is NO potential energy since:

[tex]\frac{1}{2}k(0^2) = 0 J[/tex]

Thus:

[tex]ME = \frac{1}{2}mv^2[/tex]

Plug in the given values:

[tex]ME = \frac{1}{2}(0.50)(1.5^2) = \boxed{0.5625 \text{ J}}[/tex]

Answer:

[tex]1.74\times10^3 kg; 100m[/tex]

Explanation:

Step a: mass of the car. Let's grab the definition of kinetic energy: [tex]K= \frac12 mv^2[/tex]. We have K, we have v (which we should convert in meters per second, dividing by 3.6) to get:[tex]4.22\times10^5 = \frac12m(22.03)^2 \rightarrow m= 2\times4.22 / 495.22 \times 10^5 = 1.74 \times 10^3 kg[/tex]

Point a is done.

Now for the (b)reaking part. (I'm sorry, it's an horrible joke, but I couldn't resist)

In theory we have the mass, we have the force, so we could find the acceleration, find how long it takes to slow down, and then find the distance traveled. Too long. Let's do things more easily: when the car slows down to 56 km/h it will have a different kinetic energy. The difference in kinetic energy is the work done by the breaking force ofer the slowing distance.

[tex]K_f-K_i=W[/tex] A quick note on signs: if you look carefully the final kinetic energy will be less than the initial value, thus the work will be negative: it means it's correct, since the work is against the motion, slowing it down. Let's get calculating, first by converting 56 kmh in m/s (15,56 m/s), then finding the final kinetic energy:

[tex]K_f =\frac12 (1.74\times10^3) (15.56)^2 =2.11 \times 10^5 J[/tex]

The difference will be the work done by the force, or

[tex](2.11 - 4.22) \times 10^5 = \vec F\cdot \vec x=Fx[/tex] where  we are assuming that force and displacement have the same line of actions to simplify the dot product.

[tex]2.11\times 10^5 = 2100x = 1.00\times 10^2 m[/tex]

Answer:

●Bx=Bcos40

Bx=10 × 0.76

Bx=7.6

●By=Bsin40

By=10×0.64

By=6.4

Hope it will help you.

Answer:

Explanation:

As the velocity is constant, Net force is zero. This means that the friction force must equal the applied force in the horizontal direction.

Ff = Fcosθ

if we had a coefficient of kinetic friction μ, we could quantify the friction force more precisely.

μN = Fcosθ

μ(mg - Fsinθ) = Fcosθ

μmg = Fcosθ + μFsinθ

100μ = F(cos30 + μsin30)

F = 100μ / (cos30 + ½μ)

Ff = 100μcos30 / (cos30 + ½μ)

A 100 N create is being pulled at a constant velocity by a rope a 30 degrees to the horizontal as depicted in the diagram given in question the force of friction Ff = 100μcos30 / (cos30 + ½μ).

A force in physics is an effect that has the power to alter an object's motion. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

As the velocity is constant, Net force is zero. This means that the friction force must equal the applied force in the horizontal direction.

Ff = Fcosθ

if we had a coefficient of kinetic friction μ, we could quantify the friction force more precisely.

μN = Fcosθ

μ(mg - Fsinθ) = Fcosθ

μmg = Fcosθ + μFsinθ

100μ = F(cos30 + μsin30)

F = 100μ / (cos30 + ½μ)

Ff = 100μcos30 / (cos30 + ½μ)

the force of friction Ff, is 100μcos30 / (cos30 + ½μ).

To learn more about force refer to the link:

brainly.com/question/13191643

#SPJ5

[tex]\omega = 21.8\:\text{rad/s}[/tex]

Explanation:

We know that there are [tex]2\pi[/tex] radians in one revolution and 60 seconds in one minute so we can easily convert the rev/min unit to rad/s using the following conversion factors:

[tex]208\:\dfrac{\text{rev}}{\text{min}}×\dfrac{2\pi\:\text{rad}}{1\:\text{rev}}×\dfrac{1\:\text{min}}{60\:\text{s}}[/tex]

[tex]\;\;\;\;\;=21.8\:\text{rad/s}[/tex]

Hi there!

Since the collision is elastic, we must also satisfy the following condition:

Ei = Ef, or:

KEi = KEf

Begin by writing an expression for momentum. (p = mv) Remember that one ball's direction is negative; in this instance, we can let the second ball be moving LEFT.

mv1 + mv2 = mvf1 + mvf2

0.220(1.84) + 0.220(-.530) = 0.220(vf1 + vf2)

0.2882/0.220 = vf1 + vf2

1.31 = vf1 + vf2

Now, we can express this as a conservation of energy:

1/2mv1² + 1/2mv2² = 1/2mvf1² + 1/2mvf2²

Plug in values and simplify:

0.403315 = 1/2m(vf1² + vf2²)

Simplify further:

3.6665 = vf1² + vf2²

Use the equation derived from momentum above and solve for one variable:

vf2 = 1.31 - vf1

Plug in this expression for vf2:

3.6665 = vf1² + (1.31 - vf1)²

Expand:

3.6665 = vf1² + 1.7161 - 2.62vf1 + vf1²

Simplify:

1.9504 = -2.62vf1 + 2vf1²

Solve for vf1 using a graphing calculator:

vf1 = -0.53 m/s or 1.84 m/s; we must figure out which one is correct.

Since v1 is heading to the right initially with a velocity of 1.84 m/s, we know that the ball's velocity could not have stayed the same in both magnitude and direction, so the final velocity must be -0.53 m/s.

Now, we can solve for the velocity of the other ball (initial of 0.53 m/s):

vf2 = 1.31 - (-0.53) = 1.84 m/s.

Now, you could have also made the connection that when two balls of the SAME MASS experience an ELASTIC collision, the velocities are simply "exchanged" from one to another. I just used this more "extensive" method to prove this.

Answer:

The Aluminum

Explanation:

With a larger specific heat, water requires more heat to raise its temperature by a temperature degree.

In this system, with equal masses of water and aluminum, the heat moving from the aluminum lowering its temperature by one degree is not sufficient to raise the water temperature by one degree.

W = 25 J

Explanation:

Work done on an object is defined as

[tex]W = Fd = (10\:\text{N})(2.5\:\text{m}) = 25\:\text{J}[/tex]

Answer:

Steady-state theory, in cosmology, a view that the universe is always expanding but maintaining a constant average density, with matter being continuously created to form new stars and galaxies at the same rate that old ones become unobservable as a consequence of their increasing distance and velocity of recession.

Cosmic inflation is a faster-than-light expansion of the universe that spawned many others. ... Cosmic inflation solves these problems at a stroke. In its earliest instants, the universe expanded faster than light (light's speed limit only applies to things within the universe).

Answer:

Pick c is the right one

Explanation:

5.0m/s

Answer:

10.83 Amperes

Explanation:

if   A ⇒ current

W = VA

1300 = 120 x A

1300 / 120 = A

10.83 = A

Answer:

Instrument Use

Accelerometer Measures acceleration

Altimeter Measures altitude of an aircraft

Ammeter Measures electric current in ampere

Anemometer Measures wind speed

Answer:

A. Determine the equation of constraints

Answer:

a vacuum tube is NOT a solid state component

Answer:

F = - K x for spring     (note that that F here is given in grams, F = m g is correct)

K here is 100 g / cm      for the spring constant

x = -420 g / 100 g/cm = -4.2 cm

The spring would compress 4.2 cm for a total length of 20 - 4.2 = 15.8

d)  to compress the spring 6.8 cm one can see that the load would be 680 g

This question involves the concepts of the law of conservation of energy and specific heat capacity.

This collector can deliver "7.96 x 10⁻⁴ m³/min" of water at an output temperature of 60°C.

According to the law of conservation of energy:

Solar Energy = Energy Required to raise the temperature of the water

Solar Power = Energy Required to raise the temperature of the water

[tex]IA=\frac{mC\Delta T}{t}\\\\\frac{m}{t}=\frac{IA}{C\Delta}[/tex]

where,

[tex]\frac{m}{t}[/tex] = mass flow rate = ?

I = solar radiation = 660 W/m²

A = Area = 3.8 m²

ΔT = change in temperature = 60°C - 15°C = 45°C

C = specific heat capacity = 4200 J/kg.°C

Therefore,

[tex]\frac{m}{t}=\frac{(660\ W/m^2)(3.8\ m^2)}{(4200\ J/kg.^oC)(45^oC)}\\\\\frac{m}{t}=(0.0133\ kg/s)(\frac{60\ s}{1\ min})\\\\\frac{m}{t}=0.796\ kg/min[/tex]

Now, the volume flow rate will be:

[tex]\frac{V}{t}=\frac{(\frac{m}{t})}{(density\ of\ water)}=\frac{(0.796\ kg/min)}{(1000\ kg/m^3)}\\\\\frac{V}{t}=7.96\ x\ 10^{-4}\ m^3/min[/tex]

Learn more about the law of conservation of energy here:

brainly.com/question/20971995?referrer=searchResults

The attached picture explains the law of conservation of energy.

Answer: for part A Its A the ANSWER for part B its D

Explanation:

Answer:

a and b

Explanation:

[tex] \large★·.·´¯`·.·★ {Answer}★·.·´¯`·.·★[/tex]

As we know that Kinetic Energy is the Energy that is possessed by a moving object. and if the object is at rest then it doesn't have velocity therefore there is no kinetic Energy.

In the numerical terms we can express it as : -

[tex]꧁  \:  \large \frak{Eternal \:  Being } \: ꧂[/tex]

Answer:

22Ω

Explanation:

if    V ⇒ voltage

      I ⇒ current

      R ⇒ resistance

V = IR

220 = 10 x R

220 / 10 = R

22 = R

Answer:

0

Explanation:

0 is the answer

Hi there!

With a Force/Displacement curve, we must take the integral (area underneath the curve) to calculate the work done.

We know that:

W = ΔKE

Calculate the work by finding the area underneath the force curve from

x = 0 to 3 m:

We can use a trapezoid:

A = 1/2(3 + 2)(3) = 7.5 J

This is the amount of work done, and since the object starts from rest:

7.5J = KEf - KEi (0 J)

7.5J = KEf = 7.5 J

Answer:

TRUE

FALSE

TRUE

TRUE

TRUE

TRUE

Explanation:

1. Most EM waves has the same speed. True

2. EM waves travel at the speed of 4x108 m/s. False

3. Electromagnetic waves are transverse waves consisting of changing electric fields and changing magnetic fields. True

4. Electromagnetic waves transfer energy through a vacuum. True

5. A wave is a disturbance that transfers energy. True

Answer:

14. scolded

15. supporter

16. i am not sure but I think it is removes

17. comfortable

18. outdated

19. drink

20. it can be fantastic or wealthy

Answer:

14. Reicon's parents admonished him for breaking their antique collection,

15. I am an advocate of anti-corruption movement in the country.

16. The hotel abolishes its rice-all-you-can policy to avoid wastage of food.

17. The country has a very tropical climate where it only has dry and wet

seasons similar to other countries in Southeast Asia

18. The obsolete books and other references in the library resulted to the

removal in the shelves and inventory.

19. Beverages, such as juices, milk, beers and sodas, have increased in,due to low supply and importation issues.

20. The luxurious life of my cousin in an exclusive subdivision in Ta makes me inspired to dream and work hard for me to escape this unp.

Answer:

Explanation:

α = Δω/t = (0 - ωi)/0.50 = -2ωi rad/s²

ωf² = ωi² + 2αθ

θ = (ωf² - ωi²) / 2α

2π/4 = (0² - ωi²) / (2(-2ωi))

2π/4 = ωi / 4

ωi = 2π rad/s

α = -2(2π) = -4π rad/s²

a = rα = 0.23(-4π) = 0.92π m/s² ≈ -2.89 m/s²

as the time to stop approaches zero, acceleration goes toward infinity.

Answer:

currents which circulate in conductors like swirling eddies in a stream in electromagnetic series....

Answer:

it's ahfdfhhh hhgfdjjjjuyggffdddcff