A car with a mass of 1200kg is travelling at 72kmh^-1 when the driver sees a dog running across the street. He applies the brakes and 10 seconds later the car is moving at 18kkmh^-1.

A) Calculate the initial momentum of the car.
B) Calculate the final momentum of the car.
C) Calculate the change in momentum of the car.
D) Calculate the net force applied by the brakes of the car.​

Mass is not required

[tex]\\ \rm\longmapsto W=Fscos\Theta[/tex]

[tex]\\ \rm\longmapsto W=20(5)cos30[/tex]

[tex]\\ \rm\longmapsto W=100\times \dfrac{\sqrt{3}}{2}[/tex]

[tex]\\ \rm\longmapsto W=50\sqrt{3}J[/tex]

Answer:

[tex]we \: have \\ w = fs \cos( \alpha ) \\ f = 20n \\ m = 2kg \\ s = 5m \\ \alpha = 30 \\ \\ then \: w = 20 \times 5 \times \cos(30) \\ 100 \cos(30) \\ = 100 \frac{ \sqrt{3} }{2} \\ = 50 \sqrt{3} \\ = 86.6 \: joule\\ thank \: yo[/tex]

Its speed is 4m/s

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Answer:

B

Explanation:

In this process on merry go round there is not any external torque so angular momentum will be conserve. Mass is always conserved.

Answer:

Element Chart

Explanation:

It is a chart that provides many different elements.

Zooming I. On the image the red line is just short of the 3rd line past the 7 so it is not 7.3 but just a little under.

Answer: 7.28

Answer:

all of these very easy questions

Answer:

Explanation:

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Answer:

d=s

t

d=36

4

d=10m/s

Explanation:

distance is equal to speed over t therefore 36 divide by 4 is 10

Answer:

no worries

Explanation:

Leave it to me.

Answer:

17 cm

Because the equation you're using is ∆d=df

Answer:

16.18 mph

Explanation:

the speed of elevators =

(783×3600)/(33×5280) =

2,818,800/174,240 = 16.18 mph

Answer:

S=2,P=6,D=10,F=14. The total number of electrons contained by s,p,d,f subshells is 32

Answer:

+5m/s

Explanation:

When doing the math we figure out that e is going to be slowing down at -4m/s² for 5 seconds. In total he is slowing down -20m/s which we take from the total speed of +25m/s to get his current new speed.

Explanation:

Move past each other.

Have a good day.

Answer:

Divide by 1609

Explanation:

So to convert from m/s to m/s divide by 1609

Answer:

kinetic

Explanation:

kinetic energy is powered by motion or gravity the steeper the hill is the faster a ball will roll

[tex]\\ \rm\longmapsto Force=Mass(Acceleration)[/tex]

[tex]\\ \rm\longmapsto Force=25(10)[/tex]

[tex]\\ \rm\longmapsto Force=250N[/tex]

Answer:

density is equal to mass divided by volume (m/v)

volume: 12×8×9=864cm³

75÷864=0.09

Answer: 0.09g/cm³

The area which touches the sand floor of 4 feet of the bull is less than the man.

because the area of surface of contact is more in bull than in man. More is the area of contact, leads is the force or pressure affected.

Answer:

It is:

0.00477

0.00000301

Answer:

what is it for

Explanation:

Answer:

½mv²=mgh

g=½(V²/h)

Explanation:

When an object is held at a height, it posses gravitational potential energy which is mgh, where m= mass, h=height, g=acceleration due gravity

When the object is dropped, the potential energy will be converted to kinetic energy which is ½mv², where V=velocity at which the object moves.

V=∆h/t, ∆h is change in height with respect to time.

½mv²=mgh

Mass cancel out,

g=v²/2h

This implies that g does not depend or is not affected by mass. Hence heavy object and light object will reach the ground at the same time when dropped from the same height. When air resistance is negligible.

Hi :)

The formula for velocity is

v = displacement / change in time

velocity = 100 m / 4 seconds

velocity = 25 m/s

The formula for velocity is

v = displacement / change in time

velocity = 100 m / 4 seconds

velocity = 25 m/s

Answer:

IV what is it's potential energy at the maximum height

Answer:

1. heating

2. entertainment

3. cooling

4.educational purpose

5.comfort

Answer:

Acceleration is 2.78 m/s²

Explanation:

Since the car is from rest, initial velocity, u is zero.

from first newton's equation of motion:

[tex]{ \bf{v = u + at}} \\ [/tex]

v is final velocity

u is initial velocity

a is acceleration

t is time

70 km/h is (70 × 1000 ÷ 3600) m/s = 19.44 m/s

[tex]{ \sf{19.44 = 0 + (a \times 7)}} \\ { \sf{7a = 19.44 }} \\ { \sf{a = 2.78 \: {ms}^{ - 2} }}[/tex]

Answer:

My believe the answer is

A.) or B.)

Explanation:

Here is why I think A is the answer.

If we use the process of elimination, it would look like this,

a) Porque el aire tiene una temperatura menor que la de su cuerpo; por eso se propaga más rápido.

This makes sense because we all know in winter the weather is very cold and freezing.

b) Porque la temperatura de su cuerpo, siente el aire frio que entra por la ventana.

I feel like this answer is the question, but it could also be an answer, sorry, I'm a little uncertain.

c) Porque el calor de su cuerpo se propaga al medio ambiente, al ser la temperatura del niño mayor que la del aire exterior.

This answer has nothing to do with the question, plus it is very false, our body heat is not enough to overcome the very cold temperature from outside.

d) Porque la temperatura del aire es igual a la temperatura del cuerpo.

This is false because again our body heat is not even compared to the freezing cold temperatures from the winter.

The expression for the position of the particle in terms of velocity and time is given as, s = vt

The given expression:

To find:

Determine the value of the constants from second equation of motion given as:

[tex]s = vt + \frac{1}{2}at^2\\\\substitute \ the \ given \ value \ of \ a\\\\s = vt + \frac{1}{2}(c_1 + c_2v)t^2\\\\s = vt + \frac{1}{2} c_1 t^2 + \frac{1}{2} c_2vt^2\\\\divide \ through\ by \ t^2\\\\\frac{s}{t^2} = \frac{v}{t} + \frac{1}{2} c_1 + \frac{1}{2} c_2v\\\\multiply \ through \ by \ 2\\\\\frac{2s}{t^2} = \frac{2v}{t} + c_1 + c_2v\\\\when \ t = 0\\\\0 = 0 +c_1 + c_2v\\\\c_1 + c_2v = 0\\\\from \ the \ original \ equation;\\\\s = vt + \frac{1}{2} (c_1 + c_2v)t^2\\\\[/tex]

[tex]s = vt + \frac{1}{2}(0)^2\\\\s = vt[/tex]

Thus, the expression for the position of the particle in terms of velocity and time is given as, s = vt

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Answer:

IV family history of breast cancer or not.

DV chance of developing breast cancer. Hypothesis Someone with a family history of breast cancer will have a higher chance of developing it.

IV: Where the grass is placed: tree shade or direct sunlight.

Dv:The grasses growth rate

Hypothesis: Grass will grow faster in direct sunlight as opposed to tree shade

IV: Fresh veggies and fruit or not

Dv: how much the students eat: will they eat more or less?

Hypothesis The students will eat more in the lunchroom when Fresh veggies and fruits are served.

IV: The dog exercise everyday for 1 hour or not.

DV: The dogs barking: less or more.

Hypothesis: The dog will bark less when someone rings the doorbell if he exercises for 1 hour every day.

Explanation:

Observation When I wish my face before bed, I get less breakouts in the morning.

Question Does nightly face washing prevent morning breakouts?

IV Washing face at night or not

Dv How much breakouts in the morning.

Hypothesis Washing your face nightly decreases the occurrence of morning breakouts.

When the data of the position and time are available, the velocity which is the ratio of change in position to change in time which is the same as the slope of the graph of the data can be calculated. For the car, we have;

1. The car moves progressively further as the time interval increases

2. The relationship between the position of the car and the time interval is that the car moves approximately 0.02 units of distance for each change in time of 0.05

3. The speed of the car is 0.398

The reason for arriving at the above values are as follows:

1. From the given data, we have that the cart moves progressively further from the start for each time interval increase, such that the cart moves progressively further from the origin in each time interval increases

[tex]\begin{array}{|c|c|} \mathbf{ Time} & \mathbf{ Position}\\2.2&0.8963\\2.25& 0.9164\\2.3 & 0.9375\\2.35 & 0.9581\\2.4 & 0.9759\end{array}\right][/tex]

2. From the given data, we have;

At time t = 2.2, the position = 0.8963

At time t = 2.25, the position = 0.9164

The change in position for a change in time from 2.2 to 2.25 is, Δx = 0.9164 - 0.8963 = 0.0201

Similarly, for the change in time from 2.25 to 2.3, which is a change of 0.05 seconds, we have;

Δx = 0.9375 - 0.9164 = 0.0211

The next interval is 2.3 to 2.35, Δx = 0.9581 - 0.9375 = 0.0206

Therefore, the change in the distance from the origin increases by approximately 0.02 for each increase in tome by Δt = 0.05 seconds

3. The slope equation is presented as follows;

[tex]Slope = \dfrac{y_2 - y_1 }{x_2 - x_1}[/tex]

The speed of the car is given by the slope of the distance time graph, where;

The horizontal variable, x, is the time, t (x = t)

The vertical variable, y, is the position, x (y = x)

Based on the given assignment of the variables to the x, and y, variables, we have;

[tex]Slope = Speed = \dfrac{y_2 - y_1 }{x_2 - x_1} = \dfrac{x_2 -x_1}{t_2 - t_1} = \mathbf{\dfrac{Final \ position - Initial \ position }{Final \ time - Initial \ time}}[/tex]

Plugging in the values in the table, we have;

[tex]Speed = \dfrac{Final \ position - Initial \ position }{Final \ time - Initial \ time} = \mathbf{\dfrac{0.9759 - 0.8963 }{2.4 - 2.2}} = 0.398[/tex]

The speed of the car = 0.398

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https://brainly.com/question/11755354

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Answer:

your answer is (B) decreasing

I hope it's helps you