Why does time seem to flow only in one direction?

Answer:

The correct option is;

d) Parallel to the plane

Explanation:

The forces acting on the box of mass, m are;

Weight of the box acting an angle, θ, equal to the inclination of the plane to the perpendicular of the plane

Weight of the box acting along the plane = m×g×sin(θ)

The force of friction along the plane = μ×m×g×cos(θ)

The total force acting downward along the plane [tex]F_{down}[/tex], = m×g×sin(θ) + μ×m×g×cos(θ)

The Force needed to pull the box up along the plane F = The total force acting downward along the plane

F = m×g×sin(θ) + μ×m×g×cos(θ) = m×g×(sin(θ) + μ×cos(θ))

When the force, Fₐ is applied vertically, the force acting along the plane = Fₐ×cos(θ)

When the force is applied perpendicular, the force acting along the plane = Fₐ×sin(θ)

When the force is applied horizontally, the force acting along the plane = Fₐ×cos(θ)

When the force is applied parallel to the plane, the force acting along the plane = Fₐ

Therefore, since Fₐ > Fₐ×cos(θ) and Fₐ > Fₐ×sin(θ), for acute angles, we have that the least force is required when the force is acting parallel to the plane.

Answer:

Explanation:

s(t) = 5t³-2t²+9

Instantaneous velocity v = ds / dt

v = ds/dt = 15t²-4t

Putting t = 7

v = 15 x 7² - 4 x 7

= 707

Instantaneous velocity at t = 7

is 707 unit .

Answer:

Explanation:

Gain  of kinetic energy + work done by friction = loss of potential energy

= 1 / 2 m ( 25² - 8² ) + work done by friction = m x 9.8 x ( 12 + 12 )

= .5 x 100 x ( 625 - 64 ) + work done by friction = 100 x 9.8 x 24

28050 + work done by friction = 23520

work done by friction = -4530 J

Answer:

Explanation:

All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun

Answer:

3360 N

Explanation:

In a first-class lever, the effort force and load force are on opposite sides of the fulcrum.

The lever is 5 m long.  The load force is 1.50 m from the fulcrum, so the effort force must be 3.50 m from the fulcrum.

The torques are equal:

Fr = Fr

(1440 N) (3.5 m) = F (1.5 m)

F = 3360 N

Answer:

distance between two points having phase difference 5.6 rad is

Φ = 2.33 m

Explanation:

given

frequency, f = 130Hz

speed of sound in air, v = 340m/s

distance between two crust or through with phase difference 2[tex]\pi[/tex] = λ (wavelength)

phase difference = 5.6 rad

note: distance between two points having a phase difference = [tex]\frac{ \lambda }{2\pi }[/tex]

∴ distance between two points having phase difference of 5.6 rad is = [tex]\frac{ \lambda }{2\pi }[/tex] ×5.6

Recall

v = f × λ

speed = frequency × wavelength

wavelength = speed/frequency

λ  = v/f

λ  = 340/130 = 2.615 m

∴ distance between two points having phase difference 5.6 rad is = [tex]\frac{ 2.615 }{2\pi }[/tex] ×5.6 = 2.33 m

Answer:

d = 421.83 m

Explanation:

It is given that,

Height, h = 396.9 m

Horizontal speed, v = 46.87 m/s

We need to find the distance traveled by the ball horizontally. Let t is the time taken by the ball. Using second equation of motion for vertical direction. So,

[tex]396.9=0\times t+\dfrac{1}{2}\times 9.8 t^2\\\\t=9\ s[/tex]

Now d is the distance covered by the cannonball. So,

[tex]d=vt\\\\d=46.87\times 9\\\\d=421.83\ m[/tex]

Hence, this is the required solution.

Answer:

radio waves, micro wave, x-rays

Explanation:

Explanation:

A MAGNET IN WHICH MAGNETIC FIELD IS PRODUCED BY ELECTRIC CURRENT IS CALLED ELECTROMAGNET.

THE ELECTROMAGNETS ARE HAVE 3 TYPES. THERE ARE:

◇ ROBUST ONES

◇ THE SUPERCONDUCTORS

◇ HYBRIDS.

Answer:

v = 6t² + t + 2, s = 2t³ + ½ t² + 2t

59 m/s, 64.5 m

Explanation:

a = 12t + 1

v = ∫ a dt

v = 6t² + t + C

At t = 0, v = 2.

2 = 6(0)² + (0) + C

2 = C

Therefore, v = 6t² + t + 2.

s = ∫ v dt

s = 2t³ + ½ t² + 2t + C

At t = 0, s = 0.

0 = 2(0)³ + ½ (0)² + 2(0) + C

0 = C

Therefore, s = 2t³ + ½ t² + 2t.

At t = 3:

v = 6(3)² + (3) + 2 = 59

s = 2(3)³ + ½ (3)² + 2(3) = 64.5

Answer:

Flexibility Increases

Pre-breathe time decreases

Mass of suit decreases.

Explanation:

Spacesuits are designed for space shuttles when a person goes to explore the galaxy. The spacesuits shuttle era are pressurized at 4.3 pounds per inch. The gas in the suit is 100% of oxygen and there is more oxygen to breathe when the altitude of 10,000 is reached. This will decrease the breathing time and mass of suit.

Answer:

It slows down as the cross-section becomes smaller is the correct answer to this question.

Explanation:

Answer:

[tex]\boxed{\mathrm{Density = 1.1 \ g/cm^3}}[/tex]

Explanation:

Volume of fresh water:

Volume = Mass / Density

Volume = 1600/1

[tex]V_{1}[/tex] = 1600 cm³

Volume of sea water:

Volume = Mass / Density

Volume = 1200/1.2

Volume = 1000 cm³

So,

Total Volume when they are mixed = 1600+1000

Total Volume when they are mixed = 2600 cm³

And,

Total Mass when they are mixed = 1600+1200

Total Mass when they are mixed = 2800 g

Now, Measuring the density of the mixture:

Density = Mass / Volume

Density = 2800/2600

Density = 1.1 g/cm³

Answer:

[tex]\mathrm{1.086 \: g/cm^3 }[/tex]

Explanation:

Volume of fresh water ⇒ 1600 cm³

Density of fresh water ⇒ 1 g/cm³

Volume of sea water ⇒ 1200 cm³

Density of sea water ⇒ 1.2 g/cm³

[tex]density=\frac{mass}{volume}[/tex]

[tex]mass=density \times volume[/tex]

Calculate mass of fresh water.

[tex]m=1600 \times 1[/tex]

[tex]m=1600 \: g[/tex]

Calculate the mass of sea water.

[tex]m=1200 \times 1.2[/tex]

[tex]m=1440 \: g[/tex]

Find the density of the mixture.

[tex]density=\frac{mass}{volume}[/tex]

[tex]\rho = \frac{1600+1440}{1600 + 1200}[/tex]

[tex]\rho = \frac{3040}{2800}[/tex]

[tex]\rho= 1.0857...[/tex]

Answer:

A. 5.08 secs.

B. 10.16 secs.

C. 126.50 m.

D. 373.36 m

Explanation:

Data obtained from the question include the following:

Initial velocity (u) = 65 m/s

Angle of projection θ = 50°

A. Determination of the time taken to reach the peak.

Initial velocity (u) = 65 m/s

Angle of projection θ = 50°

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =.?

t = u•Sine θ/g

t = (65 × Sine 50) /9.8

t = 5.08 secs.

B. Determination of the total time spent by the ball in air.

Time (t) taken to reach the peak = 5.08 secs.

Total time (T) spent by the ball in air =?

T = 2t

T = 2 × 5.08

T = 10.16 secs

Therefore, the total time spent by the ball in air is 10.16 secs.

C. Determination of the maximum height.

Initial velocity (u) = 65 m/s

Angle of projection θ = 50°

Acceleration due to gravity (g) = 9.8 m/s²

Maximum height (H) =..?

H = u²•Sine² θ / 2g

H = 65² × (Sine 50)² / 2 × 9.8

H = 4225 × (Sine 50)² /19.6

H = 126.50 m

Therefore, the maximum height reached by the ball is 126.50 m.

D. Determination of the horizontal distance travelled by the ball.

Initial velocity (u) = 65 m/s

Angle of projection θ = 50°

Acceleration due to gravity (g) = 9.8 m/s²

Horizontal distance (R) =..?

R = u²•Sine 2θ / g

R = 65² × Sine (2×30) / 9.8

R = (4225 × Sine 60) / 9.8

R = 373.36 m

Therefore, the horizontal distance travelled by the ball is 373.36 m

Answer: 2 seconds

Explanation:

Since I've only memorized a couple of formulas for these things, I need to do the time first:

I'll use the formula  Distance = (1/2) (acceleration) (time)²

20 m = (1/2) (10 m/s²) (time)²

Time² = (20 m) / (5 m/s²)

Time² = 4 sec²

Time = 2 seconds

Now ...

-- When the ball hits the ground, it has been falling for 2 seconds.

-- Its acceleration has caused its speed to increase by 10 m/s every second.

-- So after 2 seconds, its speed has grown to (2 s) (10 m/s²) = 20 m/s .

Answer:

Explanation:

For entropy change the formula is

ΔS = ΔQ / T

ΔQ = Δ H

ΔS = Δ H / T

Given

Δ H = + 162.8 kJ

We can take equilibrium temperature as average temperature of the whole process

So, T = 273 + 87 = 360 K

ΔS = Δ H / T

=  162.8 kJ  / 360

= +  0.508 kJ / K .

When the magnitude of the heat transfer for the process is 162.8 kJ, Then the entropy change for the mixing process, in kJ/K is = + 0.508 kJ / K

For The entropy change, the formula is

Then ΔS = ΔQ / T

After that ΔQ = Δ H

Then ΔS = Δ H / T

Given as per question are:

Then Δ H = + 162.8 kJ

Now We can take equilibrium temperature as average temperature of the whole process are:

So, T is = 273 + 87 = 360 K

Then ΔS = Δ H / T

After that = 162.8 kJ / 360

Therefore, = + 0.508 kJ / K.

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The correct answer is D. The movement of the molecules will gradually increase.

Explanation:

At the beginning of the model the state of matter of the water is solid, in this, particles have a defined arrangement and are together, which stops particles from moving freely and only allows them to vibrate. However, as the substance is heated the thermal energy (heat) increases in the sample, this causes particles to move more and the arrangement of it changes. Due to this, when the ice melts and there is liquid water particles move more than in solid states, which makes ice lacks a defined shape. Moreover, as the heat continues to increase the thermal and kinetic energy (movement) increases, indeed in gas state (water vapor) particles will move freely. This means the movement or kinetic energy in particles gradually increases in the model.

Answer: D

Explanation:

Answer:

 V₁ = 6 V ,  V₂ = V₃ = 3 V

Explanation:

To solve this circuit we must remember that there are two fundamental types of construction in series and parallel.

* a serial circuit there is only one path for current

in this circuit the constant current in the entire circuit and the voltage is the sum of the voltage of each term

* Parallel circuit in this there are two or more paths for the current

in this circuit the voltage is constant and the east is divided between each branch

with these principles let's analyze the proposed circuit

The DC battery is in parallel with resistor R1 and the equivalent of the other branch,

as in a parallel circuit the voltage is constant

               V₁ = 6 V

in the other branch (23) it forms a series construction, where the current is constant

               6 = iR₂ + iR₃

as they indicate that each resistance has the same value

              6 = 2 iR

              V = V₂ = V₃ = 3 V

Answer:

B

Explanation:

If the light is pointing down ,and then hits a surface of a 60 degree angle, then the direction will be away from the light since the light is touching a surface that is flat of a 60 degree angle then it will reflect off of it Perpendicular.

The statement that is the most true regarding the states of matter is the first statement.

A. Most matter on Earth exists as a solid, liquid, or gas.

This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.

Therefore, B is incorrect.

C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.

D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.

Matter can be defined as the material substance which constitutes the observable nature. Most matter on Earth exists as a solid, liquid, or gas. Plasma is also the state of matter found in daily life. The correct option is A.

All the materials which we see in our daily lives are made up of matter. Matter can be classified into different states such as solid, liquid and gas based on the intermolecular forces and the arrangement of particles. All the three states of matter can be converted from one form to another.

The molecules of solid are tightly packed and they have strong intermolecular forces which also has a definite shape and volume. The liquids have weak intermolecular forces than the solids and it acquire the shape of the vessel.

The intermolecular forces in gases are negligible and they do not have any fixed shape or volume.

Thus the correct option is A.

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gravity means that is not a force but the gravitational force is a force

For example we call the earth has a gravitational force but on moon we say that it doesn't have gravity

Answer:

Gravity is the Earth’s pull on a body, lying on near the surface of the Earth.

Gravitational force is the force of attraction acting between any two bodies.

Answer:

No. A vacuum does not exist at an altitude of 75,000 ft

Explanation:

There is naturally a decrease in air pressure as one goes higher into the atmosphere. However, vacuum conditions are not actually present within the atmosphere as there are still significant amounts of gases even at really high altitudes.

To prove this we know that planes cannot fly in a vacuum, because they need to burn air in order to gain propulsion from their engines.

One military plane - the SR-71 flew at about 90,000 feet.

This is a lot higher than 75,000 feet. For it to be able to at that altitude, it means that there was a significant quantity of air left even at 90,000 feet.

Answer:

F= GMm/r^2

Explanation:

According to newtons formula for gravitation,

F= GMm/r^2

Answer:

(a) and (b)

Explanation:

Energy is the capacity to do work, and exists in various forms. These forms can be converted one to another by the use of appropriate means. Some examples are sound, mechanical, solar, light, which causes the sensation of vision, etc. energy is measured in Joules (J).

The rate of transfer of energy is called power.

i.e Power = [tex]\frac{energy}{time}[/tex]

It is measured in Watts (W).

When a white light is disperses into its colors, gray and black are not part of the colors. And a black sometimes could be as a result of the absorption of all other colors of light.

Answer:

59.19%

Explanation:

Step 1:

Data obtained from the question. This include the following:

Input temperature = 495 K.

Output temperature = 293 K.

Efficiency =..?

Step 2:

Determination of the efficiency of the engine.

Efficiency is simply defined as the ratio of output to input times 100. Mathematically, it is expressed as:

Efficiency = output /input x 100

With the above formula, we can calculate the efficiency of the engine as follow:

Input temperature = 495 K.

Output temperature = 293 K.

Efficiency =..?

Efficiency = output /input x 100

Efficiency = 293/495 x 100

Efficiency = 59.19%

Therefore, the efficiency of the engine is 59.19%

Answer:

0.41

Explanation:

Trust me bro

Answer:-

Cognitive behavioral therapy (CBT) is a form of psychological treatment that has been demonstrated to be effective for a range of problems including depression, anxiety disorders, alcohol and drug use problems, marital problems, eating disorders and severe mental illness.  CBT leads to significant improvement in functioning and quality of life.

Hope this help :)

And can u give brainliest.

The goal of cognitive behavioral therapy (CBT), a type of psychotherapy, is to alter unhelpful thought and behavior patterns.

Cognitive Behavioral Therapy (CBT) is a form of psychotherapy that focuses on changing negative patterns of thinking and behavior. It is a goal-oriented and structured therapy that aims to help individuals identify and modify their thoughts and behaviors that may be contributing to psychological distress.

CBT is based on the idea that the way people think about a situation affects how they feel and how they behave. In CBT, therapists work with clients to identify and challenge negative and irrational thoughts and beliefs, and replace them with more realistic and positive ones. This can lead to improved mood and behavior.

CBT is a collaborative therapy, where the therapist and client work together to set goals and develop strategies to achieve them. CBT typically involves a specific number of sessions, with the number and frequency of sessions varying depending on the individual's needs and goals.

CBT has been found to be effective in treating a wide range of mental health issues, including anxiety disorders, depression, post-traumatic stress disorder, obsessive-compulsive disorder, and eating disorders. It is often used in combination with other treatments, such as medication, and can also be adapted for use with children and adolescents.

Therefore, To change unhelpful thought and behavior patterns is the aim of cognitive behavior therapy (CBT), a type of psychotherapy.

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Answer:

6m^3

Explanation:

volume of box= length×breadth×height

= 2×3×1

=6m^3

Answer:

i n k ok

Explanation:

Answer:

I think the answer is 8km2

Answer:

Distance = 17km

Displacement = 12.6 km

Explanation:

south 12km

west 4km

north 1km

Total distance = 12 + 4 + 1 = 17km

Total displacement = in picture above.

Answer:

Explanation:

The rest energy of any substance is defined by the Einstein's mass energy equivalence relation. Thus the rest mass of a electron is 9.11x10^-31 kg. The speed of light is 299,792,458 m/s. Thus multiplying the square of speed of light with the rest mass of electron gives the rest energy of the electron.

Answer;

Motion: A body is said to be in motion if it changes its position with respect to its surroundings.

Explanation:

Rest and motion are the relative terms because they depend on the observer's frame of reference. So if two different observers are not at rest with respect to each other, then they too get different results when they observe the motion or rest of a body .

one example for each. Rest: If a body does not change its position with respect to its surroundings, the body is said to be at rest. ... Motion: A body is said to be in motion if it changes its position with respect to its surroundings.

Answer:

3.33×10⁸ Pa

Explanation:

Pressure: This can be defined as the force acting normally (perpendicular) per unit area. The S.I unit of force is N/m² or Pa.

P = F/A.................. Equation 1

Where F = force created with the tooth, A = Area.

Given: F = 360 N, A = 1.08 mm² = 1.08/1000000 = 1.08×10⁻⁶m.

Substitute this values into equation 1

P = 360/1.08×10⁻⁶

P = 3.33×10⁸ Pa.

Hence the pressure created = 3.33×10⁸ Pa