Can someone help me with this science one please

Answer:

Approximately [tex]2.8 \times 10^{5} \; \rm J[/tex] (assuming that the car is moving on level ground, and that there is no friction to hinder the motion of the car.)

Explanation:

Formula for the kinetic energy, [tex]\rm KE[/tex], of an object of [tex]m[/tex] travelling at velocity [tex]v[/tex]:

[tex]\displaystyle \text{KE} = \frac{1}{2}\, m \cdot v^{2}[/tex].

Let [tex]v_1[/tex] and [tex]v_2[/tex] denote the velocity of this car before and after the acceleration.

Kinetic energy of this car before the acceleration:

[tex]\begin{aligned}\text{KE}_1 &= \frac{1}{2}\, m \cdot {v_1}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (12\; \rm m \cdot s^{-1})^{2} \\ &\approx 5.0 \times 10^{4}\; \rm J\end{aligned}[/tex].

Kinetic energy of this car after the acceleration:

[tex]\begin{aligned}\text{KE}_2 &= \frac{1}{2}\, m \cdot {v_2}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (30.6\; \rm m \cdot s^{-1})^{2} \\ &\approx 3.3\times 10^{6}\; \rm J\end{aligned}[/tex].

Assume that this car was travelling on level ground. Also assume that there is no friction to hinder the motion of this car. The work of the engine of this car  would be equal to the amount of [tex]\rm KE[/tex] that the car has gained:

[tex]\rm KE_2 - KE_1 \approx 2.8\times 10^{5}\; \rm J[/tex].

Answer:

a

Explanation:

occurs when the crest of one wave meets the trough of another wave as they travel from two different points in the same direction and at the same frequency

Answer:

I'm pretty sure the answer would be C.

Answer:

Bodies in space traveled in circles.

The planets revolved around the Earth.

Explanation:

Answer:  b and d

Explanation:

got it right

Answer:

A. Kate’s location is at a lower latitude.

C. Kate’s location absorbs sunlight that travels a shorter distance through the atmosphere.

Explanation:

^

Answer:

edmentum :-))

Explanation:

Answer:

Explanation:

In physics the term velocity is always a vector.  All that means is that it's got a direction with it.  which also means this vehicle that was traveling in the east direction and then turned left is and is now ,  maybe traveling in a north direction.  Making the guesses that the car was traveling due East and is now traveling due North, then the car has changed it's velocity by 40 m/s.  By The Way do you happen to know how fast 40 m/s is?  it's about 144 Kph  :0  or about 90 MPH    so this guy is also speeding  :D,  write him a ticket ... :P

Answer:

both hit qaulity

Explanation:

Newton's Third Law says that every interaction involves two forces - in this case (1) hammer pushes nail, and (2) nail pushes hammer. When a hammer hits a nail, Newton's Third Law says that the force that the hammer exerts on the nail is exactly the same size as the force the nail exerts on the hammer.

Answer:

(1) 1×10⁻⁴

Explanation:

From the question,

α = (ΔL/L)/(ΔT)............. Equation 1

Where α = linear expansivity of the metal plate, ΔL/L = Fractional change in Length, ΔT = Rise in temperature.

Given: ΔL/L = 1×10⁻⁴, ΔT = 10°C

Substitute these values into equation 1

α  = 1×10⁻⁴/10

α = 1×10⁻⁵ °C⁻¹ .

β = (ΔA/A)/ΔT................... Equation 2

Where β = Coefficient of Area expansivity, ΔA/A = Fractional change in area.

make ΔA/A the subject of the equation

ΔA/A = β×ΔT.......................... Equation 3

But,

β = 2α.......................... Equation 4

Substitute equation 4 into equation 3

ΔA/A = 2α×ΔT................ Equation 5

Given: ΔT = 5°C, α = 1×10⁻⁵ °C⁻¹

Substitute into equation 5

ΔA/A = ( 2)×(1×10⁻⁵)×(5)

ΔA/A  = 10×10⁻⁵

ΔA/A  = 1×10⁻⁴

Hence the right option is (1) 1×10⁻⁴

Answer:

In ideal case, when no resistive forces are present then both the balls will reach the ground simultaneously. This is because acceleration due to gravity is independent of mass of the falling object. i.e. g = GM/R² where G = 6.67×10²³ Nm²/kg², M = mass of earth and R is radius of earth.

Let us assume that both are metallic balls. In such case, we have to take into account the magnetic field of earth (which will give rise to eddy currents, and these eddy currents will be more, if surface area will be more) and viscous drag of air ( viscous drag is proportional to radius of falling ball), then bigger ball will take slightly more time than the smaller ball.

Explanation:

In ideal case, when no resistive forces are present then both the balls will reach the ground simultaneously. This is because acceleration due to gravity is independent of mass of the falling object. i.e. g = GM/R² where G = 6.67×10²³ Nm²/kg², M = mass of earth and R is radius of earth.

Let us assume that both are metallic balls. In such case, we have to take into account the magnetic field of earth (which will give rise to eddy currents, and these eddy currents will be more, if surface area will be more) and viscous drag of air ( viscous drag is proportional to radius of falling ball), then bigger ball will take slightly more time than the smaller ball.

Answer:

55 degrees

Explanation:

A ray of light strikes a plane mirror at an angle of incidence. The angle between the incident ray and the reflected ray is 70°. The correct option is A.

The law states that angle of incidence of the incident ray is equal to the angle of reflection through a plane surface.

Here, angle of incidence of light on a plane mirror is 35°, then the angle of reflection will also be 35°.

i = r = 35°

Then the angle between the incident ray and the reflected ray will be

i +r = 35 + 35 =70°

Thus, the correct option is A.

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Answer: I didnt understand it sorrryryyyyyyy

Explanation:

Answer:beats

Explanation:l got it right gang

Beats effects results from the interference of two sound waves that have slightly different frequencies.

Beats are produced by the superposition of two waves of slightly different frequencies but identical amplitudes. The waves alternate in time between constructive interference and destructive interference, giving the resulting wave a time-varying amplitude.

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Answer: 114 kJ/s

Explanation: Q = mcΔT = 2 kg · 3800 J/(kg C) ·15 C

Answer:

D wind

Explanation:

Heavy winds may cause much  damage to the Earth along with rain and extreme temperature changes.

Answer:

Explanation:

A and D was the right answer for me.

The two statements describe how matter changes only in a nuclear reaction are each atomic nucleus changes and atoms of new elements are formed.

Nuclear reactions is the nuclei transformation process in which one or more nuclides are produced from the collisions between an atomic nucleus and a subatomic particle (neutrons or protons)

In this reaction, the nucleus changes because, the number of protons or neutron decreases. New element with new atomic number and nucleus is formed.

Thus, the correct option is A and  D.

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Answer:

392 N

Explanation:

Mass of the ball=40kg

g=9.8m/s^2

Weight(w)=40×9.8

=392N

Answer:

5N

Explanation:

The formula formula for calculating the force between charges is expressed as;

F = kq1q2/r²

If two charges are separated by a distance r and a force between  them is 45N, then;

45 = kq1q2/r² ....1

If the distance between the charges is tripled to 3r, then;

F = kq1q2/(3r)²

F = kq1q2/9r² ... 2

Divide both expressions

45/F = (kq1q2/r²)/(kq1q2/9r²)

45/F = kq1q2/r² * 9r²/kq1q2

45/F = 9

9F = 45

F = 45/9

F = 5N

Hence the new force between them will be 5N

Answer:

b,c and d

Explanation:

Answer:

The ways to change the total energy are to either make the hill taller to increase it or make the hill lower to decrease the total energy.

Explanation:

The total mechanical energy of a system is the sum of the total kinetic energy and total potential energy.

Answer:

Percent of Female Workers = 40%

Explanation:

The percentage of the female workers in the given group of workers can be easily found by the following formula:

[tex]Percent\ of\ Female\ Workers = \frac{No.\ of\ Female\ Workers}{Total\ No.\ of\ Workers}\ x\ 100\%[/tex]

where,

Total No. of Workers = 1200

No. of Female Workers = Total Workers - No. of Male Workers

No. of Female Workers = 1200 - 720 = 480

Therefore,

[tex]Percent\ of\ Female\ Workers = \frac{480}{1200}\ x\ 100\%[/tex]

Percent of Female Workers = 40%

Answer:

It means it is the main building block material for society.

Specific heat is the amount of heat energy that causes a unit increase in temperature by required to be added to the unit mass of the substance. It can be measured by the heat capacity of a particular substance. The unit of specific heat is joule/kg/kelvin.

Material Specific heat capacity Thermal conductivity

Clay                1000                                       0.60

stone              1000                                      1.8

brick               800                                       0.73

concrete        1000                                       1.13

Advice on what this means for society:

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Answer:

i belive it is R 24

Explanation:

may i be marked brainliest?

Explanation:

mass(m)=2 kg

velocity(v)=5m/s

Now,

Kinetic energy(K.E.)=1/2mvsq

=1/2×2×5sq

=25

where,sq=square(2)

Answer:

False

Explanation:

Electrons

Answer:

C 340 m

Explanation:

may i be marked brainliest?

Answer:

What I think a Satellite is...

Explanation:

A satellite may be a moon, planet or machine that circles a planet or star. For example, Earth could be a satellite since it circles the sun. Moreover, the moon may be a obsequious since it circles Soil. As a rule, the word "satellite" refers to a machine that's propelled into space and moves around Earth or another planet in space.

Please.rate.me.a.five:)