halp me please i will give brainly

Answer:

3.35 seconds

Explanation:

Use one of the equations of accelerated motion:

Δd = v1Δt+1/2aΔt^2

and rearrange for Δt which is time

Δt = √(2Δd)/a

now we can substitute in the values

a= 9.8 (acceleration due to gravity) and Δd= 55 as that is the height of the building

Δt = √(2*55)/9.8

Δt = 3.3503s

Answer:

7.5m/s

Explanation:

Force= mass × velocity

Energy is conserved, the car and van should have the same overall force.

1500kg × 30m/s= 6000kg × final velocity

Final velocity = 7.5m/s

Answer:

the answer is force . force is applied as a push or pull

The law of reflection allows to find the results for the questions about ray reflection in a plane mirror are:

    a) Attachment we see a diagram of the incident and reflected rays, incident and reflected angles are equal.

    b)  The extension of the reflected rays is what forms the image.

    c)  The image's distance  is 20 cm behind the flat mirror.

    d) The point D (normal for an angle of 50º) cannot perceive the rays coming from point A, B, C  

    e) the Rays at points A, B, C cannot perceive in the point E.

    f) attachment we see the rays that come out from the pencil eraser.

    g) The image is behind the mirror at 15 cm.

The geometric interaction describes the interaction of light rays with surfaces, looking for where the rays are directed, it is described by two phenomenological laws:

             [tex]\theta_i = \theta_{r}[/tex]  

From these two general laws, geometric optics establishes a relationship for the formation of the image, called the constructor's equation.

            [tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]

Where f is the focal length, p and q are the distance to the object and the image, respectively.

In this exercise, the medium is a mirror, which is why it must comply with the law of reflection.

a) In the attachment we see a diagram of the incident and reflected rays for the three points.

According to the law of reflection, the incident and reflected angles are equal.

b) From the diagram we can see that the extension of the reflected rays is what forms the image, which is called virtual and is located behind the mirror.

c) In the diagram we see two rays to form the image, we see that the distance to the object is equal to the distance to the image.

From the constructor's equation a plane mirror has an infinite radius.

      p = -q

Therefore the image's distance  is 20 cm behind the flat mirror.  Therefore the distance to the object and the image are the same, the negative sign indicates that the image is behind the mirror.

d) A person located at point D (normal for an angle of 50º) cannot perceive the rays coming from point A, B, C since their angle of reflection is not equal to the incident angle.

To perceive a ray it must have an angle of incidence of 25º.

e) Point E is located very far from the pencil, so the incident angle increases as does the reflected angle.

the Rays at points A, B, C cannot perceive.

f) In the attachment we see the rays that come out from the pencil eraser, they indicate that the distance to the plane mirror is 15.0 cm,

g) The image is behind the mirror at 15 cm.

In conclusion using the law of reflection we can find the results for the questions are:

     a) Attachment we see a diagram of the incident and reflected rays, incident and reflected angles are equal.

     b)  The extension of the reflected rays is what forms the image.

     c)  The image's distance  is 20 cm behind the flat mirror.

     d) The point D (normal for an angle of 50º) cannot perceive the rays coming from point A, B, C  

    e) the Rays at points A, B, C cannot perceive in the point E.

    f) attachment we see the rays that come out from the pencil eraser.

   g) The image is behind the mirror at 15 cm.

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Answer:

Explanation:

Conservation of momentum

2500(0) + 1000(30) = (2500 + 1000)v

v = 8.57 m/s

KE = ½(2500 + 1000)8.57² = 128,571.428... = 128 KJ

The kinetic energy of the system after the collision would be 128.5  KJ.

It can be defined as the product of the mass and the speed of the particle, it represents the combined effect of mass and the speed of any particle, and the momentum of any particle is expressed in Kg m/s unit.

As given in the problem Car 1 of mass m1 is waiting at a traffic light.

Car 1 is struck from behind by Car 2 of mass m2. The two cars stick together after the collision. Car 2 was traveling at v2i = 30.0 m/s before the collision.

By using the conservation of the momentum,

2500(0) + 1000(30) = (2500 + 1000)v

v = 8.57 m/s

The final velocity of the system comes out to be  8.57 m/s.

The kinetic energy of the system after the collision,

KE =1/2×(2500 + 1000)×8.57² = 128,571.4

    = 128.5  KJ

Thus, the kinetic energy of the system after the collision would be 128.5  KJ.

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Answer:

Explanation:

constant acceleration???

assume it to be so

average speed is (10 + 30) / 2 = 20 m/s

t = d/v = 60/20 = 3 s

Answer:

Explanation:

How long does the football need to rise?

4.70/3 = 2.35 s

What height will the football reach?

h = ½(9.81)2.35² = 27.1 m

With what speed does the punter need to kick the football?

vy = g•t = 9.81(2.35) = 23.1 m/s

vx = d/t = 56.0/4.70 = 11.9 m/s

v = √(vx²+vy²) = 26.0 m/s

At what angle (θ), with the horizontal, does the punter need to kick the football?

θ = arctan(vy/vx) = 62.7°

The mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as 6.25 g.

The given parameters:

The mass of KNO₃ at 95 ⁰C is calculated as follows;

[tex]m = \frac{25\ g \times 100\ g}{100\ g} \\\\m = 25 \ g[/tex]

mass of water = 100 g - 25 g = 75 g

The mass of KNO₃ at 55 ⁰C is calculated as follows;

[tex]m = \frac{75 \ g \times 25 \ g}{100 \ g} \\\\m = 18.75 \ g[/tex]

The mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as;

[tex]m= 25\ g \ - \ 18.75 \ g\\\\m = 6.25 \ g[/tex]

Thus, the mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as 6.25 g.

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Answer:

Explanation:

Your question makes no sense.

moment of inertia is a property of the disk and its geometry.

The moment of inertia of a uniform solid disk around an axis through its geometric center and perpendicular to its flat ends is

I = ½mR² = ½(3.2)0.45² = 0.324 kg•m²

the applied torque about the same axis would be

τ = FR = 420.4(0.45) = 189.18 N•m

and the angular acceleration about the same axis would be

α = τ/I = 189.18/0.324 = 583.9 rad/s²

Answer:

Explanation:

KE = ½mv²

KE = ½(0.30)44²

KE = 290 J                 rounded to 2 s.d.

Answer:

b. inertia

Explanation:

BECAUSE OF THEIR inertia A PAIR OF SUNGLEASSES ON THE DASHBOARD WILL CONTINUE MOVING FORWARD WHEN THE CAR TURNS SHARPLY.

Explanation:

a) We need to write down first Newton's 2nd law as applied to the given system. The equations of motion for the x- and y-axes can be written as follows:

[tex]x:\;\;\;\;\;mg\sin 25° - \mu_kN = ma\;\;\;\;\;\;(1)[/tex]

[tex]y:\;\;\;\;\;N - mg\cos 25° = 0\;\;\;\;\;\;\;\;\;(2)[/tex]

From Eqn(2), we see that

[tex]N = mg\cos 25°\;\;\;\;\;\;\;(3)[/tex]

so using Eqn(3) on Eqn(1), we get

[tex]mg\sin 25° - \mu_kmg\cos 25° = ma[/tex]

Solving for the acceleration, we see that

[tex]a = g(\sin 25° - \mu_k\cos 25°)[/tex]

[tex]\;\;\;\;= 2.45\:\text{m/s}^2[/tex]

b) Now that we have the acceleration, we can now solve for the velocity of the crate at the bottom of the plane. Using the equation

[tex]v^2 = v_0^2 + 2ax[/tex]

Since the crate started from rest, [tex]v_0 = 0.[/tex] Thus our equation reduces to

[tex]v^2 = 2ax \Rightarrow v = \sqrt{2ax}[/tex]

[tex]v = \sqrt{2(2.45\:\text{m/s}^2)(8.15\:\text{m})}[/tex]

[tex]\;\;\;\;= 6.32\:\text{m/s}[/tex]

Answer:

This is the midline or the medium which is the exact middle of the graphs minimum and maximum points(which are the amplitude)

Answer:Colloid - well compacted together but not one

Answer:

x=v.t

The answer: Distance= Speed x Time

And also

Time = Distance/Speed

Speed= Distance/Time

Explanation:

We apply the definition of work by a constant force in the first three parts, but then in the fourth part we add up the answers. The total (net) work is the sum of the amounts of work done by the individual forces, and is the work done by the total (net) force. This identification is not represented by an equation in the chapter text, but is something you know by thinking about it, without relying on an equation in a list.

The definition of work by a constant force is W=FΔrcosθ.

(a) The applied force does work given by

W=FΔrcosθ=(16.0N)(2.20m)cos25.00=31.9J

(b), (c) The normal force and the weight are both at 900 to the displacement in any time interval. Both do 0 work.

(d) ∑W=31.9J+0+0=31.9J

The Universe is often studied by Scientist. The primary form of evidence that has led astronomers to conclude that the expansion of the universe is accelerating is the Observations of white dwarf supernovae.

The key evidence for that made scientist to talk about the expansion of the universe is accelerating comes from viewing and studying of white dwarf supernovae. It has been found that most distant stars all orbit at approximate speed as stars found about 30,000 light-years from their center.

Learn more about  white dwarf from

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Answer:

Explanation:

30(3) + 40(-2) + 20(x) = 0(20 + 30 + 40)

x = -0.5

30(4) + 40(-2) + 20(y) = 0(20 + 30 + 40)

y = -2

(-0.5, -2)

Answer:

1. An object is in motion when its distance from another object is changing.

2.Speed is given direction is called velocity.

Speed can be calculated.......

[tex]\text{Given that,}\\\\\text{Height, h = 17 m}\\\\\\\text{We know that,}\\\\h = v_0t + \dfrac 12 gt^2\\\\\implies h = \dfrac 12 gt^2\\\\\implies t^2 = \dfrac{2h}g\\\\\implies t =\sqrt{\dfrac{2h}g} = \sqrt{\dfrac{2(17)}{9.81}} = 1.87 ~ \text{sec}[/tex]

The magnitude of the average impulsive force imparted to the ball if it is in contact with the bat is 6000 N

The mass of the baseball, m = 0.15 kg

The speed at which it moves, v = 30 m/s

Time at which the baseball was in contact with the bat, t = 0.75 ms

t = 0.75/1000 s

t  = 0.00075 s

The impulsive force is given by the formula:

[tex]F=\frac{mv}{t}[/tex]

Substitute m = 0.15 kg, v = 30, and t = 0.00075s into the formula above:

[tex]F=\frac{0.15 \times 30}{0.00075} \\\\F=6000N[/tex]

The magnitude of the average impulsive force imparted to the ball if it is in contact with the bat is 6000 N

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Answer:

The total amount of energy, kinetic plus potential, remains the same.

Explanation:

Answer:

It could be related with the lesson from which this question belongs as far we did not read the lesson

Sorry

]A force called the effort force is applied at one point on the lever in order to move an object, known as the resistance force, located at some other point on the lever.

The way levers work is by multiplying the effort exerted by the user. Specifically, to lift and balance an object, the effort force the user applies multiplied by its distance to the fulcrum must equal the load force multiplied by its distance to the fulcrum. Consequently, the greater the distance between the effort force and the fulcrum, the heavier a load can be lifted with the same effort force.

Answer:

They are...if I'm correct Chemically combined, sorry if I'm wrong.

Answer:

The types of energy is bond breaking and bond forming in chemical energy.

Explanation:

During Chemical reaction energy is required either for breaking up bonds in case of reactants and building bonds to form products.

The chemical reaction in which energy is released is called exothermic reactions, which is released due to making up the bonds.

The chemical reaction in which energy is absorbed is called endothermic reactions, in which energy is absorbed for breaking up the bonds.

Answer:

faster over the left side than over the right side.

Explanation:

due to ball rotation, the right side is more closely matched to the speed of the air passing by as the ball progresses. This causes the air to stick more closely to the right side of the ball and that air stays with the ball surface as the spin moves it to the back of the ball and therefore leftward. As every action has an equal and opposite reaction the leftward force moving air causes the ball to experience an equal rightward force.

When the baseball curves to the right (a curveball), then the ball moves faster over the left side than over the right side.

The ball, which is thrown with a spin, is curve in the direction in which the front of the ball turns.

When a baseball curves to the right (a curveball),

Hence, when the baseball curves to the right (a curveball), then the ball moves faster over the left side than over the right side.

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Answer:

Load

Explanation:

The load in an electric circuit is any device that converts electrical energy into another form of energy.

Answer:  A) It has the same types of atoms on both sides of the reaction

arrow.

Explanation:  A balanced equation demonstrates the conservation of mass by having the same number of each type of atom on both sides of the arrow.