What is the main form of energy present in the initial state? (Initial state is when the rubber band is stretched , just before it is released)

O gravitational potential
O kinetic
O thermal
O elastic potential

Answer:

(a) 81.54 N

(b) 570.75 J

(c) - 570.75 J

(d) 0 J, 0 J

(e) 0 J  

Explanation:

mass of crate, m = 32 kg

distance, s = 7 m

coefficient of friction = 0.26

(a) As it is moving with constant velocity so the force applied is equal to the friction force.

F = 0.26 x m x g = 0.26 x 32 x 9.8 = 81.54 N

(b) The work done on the crate

W = F x s = 81.54 x 7 = 570.75 J

(c) Work done by the friction

W' = - W = - 570.75 J

(d) Work done by the normal force

W'' = m g cos 90 = 0 J

Work done by the gravity

Wg = m g cos 90 = 0 J

(e) The total work done is

Wnet = W + W' + W'' + Wg = 570.75 - 570.75 + 0 = 0 J  

Answer:

arge number of electrons free to move between the charged ions in the lattice.

Explanation:

The metallic bond occurs when an atom with few electrons is united in its last level, therefore the best way to decrease the total energy of the system is to lose all its electrons to remain with the configuration of a noble gas. The electrons that it loses cannot be acquired by other atoms since they all have few electrons, thus leaving a large number of electrons free to move between the charged ions in the lattice.

Some important characteristics emerge from this description of the metallic bond:

* It has many free electrons therefore its electrical conductivity is high

* As the charged ions are fixed, the material can be malleable, bent without breaking since the free electrons create the bond that keeps the system stable.

* As the electrons are free when heating a part of the material, these electrons acquire energy and rapidly propagate it to the other side, giving a high thermal conductivity

* As the temperature increases, the electrons acquire more kinetic energy, which is why there are more collisions between them and consequently the resistivity of the material increases.

Answer:

Angle of reflection

Explanation:

The angle between the reflected ray and the normal line is called the angle of reflection

Answer:

Activity 2 Directions: Solve the following problems using Charles' Law,

1. A 3.8 mL of a gas in a container has a temperature of 2.0K. What would the volume be if the temperature becomes 8.0K?

2. If at 27°C the volume of a dry gas is 3.0 ml. What is the new temperature if the volume increased to 7.5 ml?

3. The temperature of the gas is 460,0 mL at 3.5°C. Calculate the new volume at 1.5°C

Answer:

Penetration means forward passes can go through the opposition lines. Once these penetrative passes get through each line, it eliminates the line of players it broke through and leaves the player in possession closer to the opposition goal.

Explanation:

Answer:

a) the distance between her and the wall is 13 m

b) the period of her up-and-down motion is 6.5 s

Explanation:

Given the data in the question;

wavelength λ = 26 m

velocity v = 4.0 m/s

a) How far from the wall is she?

Now, The first antinode is formed at a distance λ/2 from the wall, since the separation distance between the person and wall is;

x = λ/2

we substitute

x = 26 m / 2

x = 13 m

Therefore, the distance between her and the wall is 13 m

b) What is the period of her up-and-down motion?

we know that the relationship between frequency, wavelength and wave speed is;

v = fλ

hence, f = v/λ

we also know that frequency is expressed as the reciprocal of the time period;

f = 1/T

Hence

1/T = v/λ

solve for T

Tv = λ

T = λ/v

we substitute

T = 26 m / 4 m/s

T = 6.5 s

Therefore, the period of her up-and-down motion is 6.5 s

Answer:

1. 5.825 × 10¹⁷ J

2. i. $ 29.125 billion ii. I would not invest in the company

3. A nuclear reaction would occur if the payload hits an airplane flying overhead and dissipates all its kinetic energy in the collision.

4. a i. The momentum will not be relativistic

ii. This is because objects with large masses do not move at relativistic speeds

b i. 155 m/s

ii. This speed wouldn't be a problem for the ship.

Explanation:

1.  A typical payload they claim to launch will weigh 1 kilogram and be accelerated to 90% the speed of light. How much electrical energy will the rail gun require to launch the probe, assuming it is 20% efficient at converting electrical energy to projectile kinetic energy?

The kinetic energy of the payload is K = (γ - 1)mc² where m = mass of payload = 1 kg, c = speed of light = 3 × 10⁸ m/s and γ = 1/√(1 - β²) where β = 0.9 (since the payload moves at 90 % speed of light)

So, K = (γ - 1)mc²

= (1/√(1 - β²) - 1)mc²

= (1/√(1 - (0.9)²) - 1) × 1 kg × (3 × 10⁸ m/s)²

= (1/√(1 - 0.81) - 1) × 1 kg × (3 × 10⁸ m/s)²

= (1/√0.19 - 1) × 1 kg × (3 × 10⁸ m/s)²

= (1/0.436 - 1) × 1 kg × (3 × 10⁸ m/s)²

= (2.294 - 1) × 1 kg × (3 × 10⁸ m/s)²

= 1.294 × 1 kg × 9 × 10¹⁶ m²/s²

= 11.65 × 10¹⁶ kgm²/s²

= 1.165 × 10¹⁷ J

Let E be the total electrical energy of the rail gun. Since 20 % of this energy is converted to kinetic energy of the payload, we have

20 % of E = K

0.2E = K

E = K/0.2

= 1.165 × 10¹⁷ J/0.2

= 5.825 × 10¹⁷ J

2 Given that typical electrical costs are about 5 cents/MJ, how much would this launch cost? Would you invest in this company?

i. how much would this launch cost?

Since the total energy required is E = 5.825 × 10¹⁷ J = 5.825 × 10¹¹ MJ and it costs 5 cent/MJ. So the total cost of energy will be total energy rate = 5.825 × 10¹¹ MJ × 5 cent/MJ = 29.125 × 10¹¹ = 2.9125 × 10¹² cents. Converting this to dollars, we have 2.9125 × 10¹² cents/100 cents/dollar = 2.9125 × 10¹⁰ dollars = 29.125 × 10⁹ dollars = 29.125 billion dollars = $ 29.125 billion

ii. Would you invest in this company?

I would not invest in the company

3. You are also concerned about safety. What happens if this projectile were to hit an airplane that is flying overhead and dissipate all of its kinetic energy in the collision? To give you a sense of scale, a large nuclear explosion generates about 1015 J of energy.

Since the kinetic energy of the payload is 1.165 × 10¹⁷ J and a nuclear explosion generates about 10¹⁵ J of energy,  then a nuclear reaction would occur if the payload hits an airplane flying overhead and dissipates all its kinetic energy in the collision.

4. The system must be able to launch probes to all parts in the sky and must be transportable on a ship. Assume that the rail gun is mounted on a frigate-class navy ship (weight = 4,000 metric tons).

a. Will the recoil momentum of the ship be relativistic? Justify your argument.

i. Will the recoil momentum of the ship be relativistic?

The momentum will not be relativistic.

ii. Justify your argument.

This is because objects with large masses do not move at relativistic speeds. Since the speed cannot be relativistic, its momentum which is the product of mass and speed is non-relativistic

b. At what speed will the ship recoil after it launches a probe? Do you think that this is a problem for the ship?

i. At what speed will the ship recoil after it launches a probe?

Since the total energy of the payload E' = K + mc² = 1.165 × 10¹⁷ J + 1 kg × (3 × 10⁸ m/s)² = 1.165 × 10¹⁷ J + 1 kg × 9 × 10¹⁶ m²/s² = 11.65 × 10¹⁶ J + 9 × 10¹⁶ J = 20.65 × 10¹⁶ J

Also, E'² = (pc)² + (mc²)² where p = momentum of payload

So, making p subject of the formula, we have

(pc)² = E'² - (mc²)²

pc = √[E'² - (mc²)²]

p = √[E'² - (mc²)²]/c

substituting the values of the variables into the equation, we have

p = √[E'² - (mc²)²]/c

p = √[(20.65 × 10¹⁶ J)² - 1kg × (3 × 10⁸ m/s²)²]/3 × 10⁸ m/s

p = √[(20.65 × 10¹⁶ J)² - (1kg × 9 × 10⁸ m²/s²)²]/3 × 10⁸ m/s

p = √[426.4225 × 10³² J² - 81 × 10³² J²]/3 × 10⁸ m/s

p = √[345.4225 × 10³² J²]/3 × 10⁸ m/s

p = 18.59 × 10¹⁶/3 × 10⁸ m/s

p = 6.20 × 10⁸ kgm/s

From the law of conservation, this momentum of the payload equals the momentum of recoil of the ship.

So, p = m'v where m' = mass of navy ship = 4,000 metric tons = 4,000 × 1000 kg = 4 × 10⁶ kg and v = speed of navy ship

So, v = p/m'

= 6.20 × 10⁸ kgm/s ÷ 4 × 10⁶ kg

= 1.55 × 10² m/s

= 155 m/s

ii. Do you think that this is a problem for the ship?

Since the ship's speed is 155 m/s, which is small for an object with such a large mass, this speed wouldn't be a problem for the ship.

Answer:

(a) v₁ = 51.96 km/h

(b) v₁ = 178 km/h

Explanation:

(a)

For having the same momentum:

m₁v₁ = m₂v₂

where,

m₁ = mass of Volkswagen = 816 kg

v₁ = speed of Volkswagen = ?

m₂ = mass of Cadillac = 2650 kg

v₂ = speed of Cadillac = 16 km/h

Therefore, using these values in the equation, we get:

[tex](816\ kg)v_1 = (2650\ kg)(16\ km/h)\\\\v_1 = (16\ km/h)(\frac{2650\ kg}{816\ kg})[/tex]

v₁ = 51.96 km/h

(b)

For having the same momentum:

m₁v₁ = m₂v₂

where,

m₁ = mass of Volkswagen = 816 kg

v₁ = speed of Volkswagen = ?

m₂ = mass of Truck = 9080 kg

v₂ = speed of Truck = 16 km/h

Therefore, using these values in the equation, we get:

[tex](816\ kg)v_1 = (9080\ kg)(16\ km/h)\\\\v_1 = (16\ km/h)(\frac{9080\ kg}{816\ kg})[/tex]

v₁ = 178 km/h

Answer:

First of all the formula is F= uR,( force= static friction× reaction)

mass= 5+25=30

F= 50

R= mg(30×10)=300

u= ?

F=UR

u= F/R

u= 50/300=0.17N

The speed is in feet per seconds so change the length of the field from yards to feet.

1 yard = 3 feet

100 yards x 3 = 300 feet

The field is 300 feet long

Time = distance / speed

Time = 300 feet / 5 feet per second = 60 seconds = 1 minute

It will take 1 minute

Answer:

A person will take 60 Seconds to walk the distance of 100 yards.

Explanation:

Data Given ;

Distance ( d ) = 100 yards = 300 Ft

Speed ( v ) = 5 Ft/s

Time ( t ) = ?

The distance travelled in unit time is called speed.

formula ; [tex]v = \frac{d}{t} \\[/tex]

On putting values,

[tex]5 = \frac{300}{t}[/tex]

[tex]t =\frac{300}{5}[/tex]

[tex]t = 60 sec[/tex]

Hence the time taken by the person is 60 sec.

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Answer:

We need, mass, gravity and height.

Explanation:

When a body falls freely from a height, its initial velocity is zero, but due to the height it has some potential energy at the top and the kinetic energy is zero.

As it falls, the potential energy is gradually converted in to the kinetic energy so that the total energy of the falling body is conserved.

At the time as the body strikes the ground, the entire potential energy is converted into the kinetic energy.

Potential energy is given by

U = m g h

where, m is the mass, g is the gravity and h is the height,

So, to get the kinetic energy we require mass, gravity and height of the body.

Answer:

∴ [T]=[WF−1V−1]

Hope this answer is right!!

Answer :

[T] = [W(F)^-1(V)^-1]

Answer:

The right solution is "4.8° east of north".

Explanation:

Given:

Distance,

= 500 km

Speed,

[tex]\vec{v}=120 \ m/s[/tex]

Wind (towards west),

[tex]v_0=10 \ m/s[/tex]

According to the question, we get

The angle will be:

⇒ [tex]\Theta=Cos^{-1}(\frac{v_0}{v_1} )[/tex]

       [tex]=Cos^{-1}(\frac{10}{120} )[/tex]

       [tex]=85.21[/tex] (north of east)

hence,

The direction must be:

⇒ [tex]\Theta'=90-85.21[/tex]

        [tex]=4.79^{\circ}[/tex]

or,

        [tex]=4.8^{\circ}[/tex] (east of north)

Answer:

The speed of projection is 34 m/s.

Explanation:

Height of building, h = 51 m

horizontal distance, d = 74 m

time, t = 8 s

Let the angle is A and the speed is u.

d = u cos A x t

74 = u cos A x 8

u cos A = 9.25 .... (1)

Use second equation of motion

[tex]h = u sin A t - 0.5 gt^2\\\\-51 = u sinA \times 8 - 0.5\times 9.8\times8\times 8\\\\u sin A = 32.8 .... (2)[/tex]

Squaring and adding both the equations

[tex]u^2 = 9.25^2 + 32.8^2 \\\\u = 34 m/s[/tex]

Answer:

parasites are creatures the gain benefit off of other animals usually harming them eg:ticks on dogs

Answer:

We know that the change in electric potential energy is defined as:

q*ΔV = ΔP

So, the change in the electric potential energy is the charge times the change in the electric potential.

For the case of an electron gas, we have:

q = -e

where -e is the charge of an electron (remember that is negative).

So, if the electron gains electric potential then:

ΔP > 0

this means that the final potential energy is larger than the initial one, then we have:

-e*ΔV > 0

This means that ΔV must be negative.

V₂ = electric potential at point 2, so it is the final electric potential

V₁ = electric potential at point 1, so it is the final electric potential

Then we should get:

ΔV = V₂ - V₁ < 0.

This means that:

V₂ < V₁

The correct option is b.

Answer:

you can use G.oogle for this question.

Answer:

93.3 degrees Celsius.

Explanation:

Answer:

Marine geologists learn about the rocks and geologic processes of the ocean basins.

Answer:

Explanation:

The mass of that science book...wow. In pounds that would be 35.2! Yikes!

Anyway, we need final velocity here, and the mass of the book has nothing to do with how fast it falls. Everything is pulled by the same gravity. A feather falls at 9.8 m/s/s and so does an elephant. Mass is useless information. The equation we will use is

[tex]v^2=v_0^2+2a[/tex]Δx  where

v is the final velocity, our unknown,

v₀ is the initial velocity which is 0 since someone had to be holding the book before dropping it,

a is the pull of gravity which is always -9.8 m/s/s, and

Δx = -120 which is the displacement (it's negative because the book falls below the point from which it was dropped). Filling in:

[tex]v^2=0^2+2(-9.8)(-120)[/tex] so

[tex]v=\sqrt{2(-9.8)(-120)}[/tex] and

v = 48 m/s

As far as how far above the bottom of the cliff the object is when it is moving at 12 m/s we will use the same equation, but the velocity will be 12:

[tex]12^2=0^2+2(-9.8)[/tex]Δx and

144 = -19.6Δx so

Δx = -7.3 m. That's how far from the top of the cliff it is. We subtract then t find out how far it is from the bottom:

120 - 7.3 = 112.7 m off the ground.

Answer:

[tex]V_2=3.3m/s[/tex]

Explanation:

From the question we are told that:

Distance [tex]d_1=1.4m[/tex]

Tangential speed [tex]V=2.2m/s[/tex]

Distance 2 [tex]d_2=2.1m[/tex]

Generally the equation for Angular velocity is mathematically given by

 [tex]w=\frac{v}{r}[/tex]

Therefore

 [tex]\frac{v_1}{r_1}=\frac{v_2}{r_2}[/tex]

 [tex]V_2=\frac{2.2*2.1}{1.4}[/tex]

 [tex]V_2=3.3m/s[/tex]

Answer:

[tex]F = 14.2 N[/tex]  

Explanation:

From the question we are told that:

Mass [tex]m=0.15kg[/tex]

Radius [tex]r=0.6[/tex]

Angular Velocity [tex]\omega=2rev/s[/tex]

                            [tex]\omega= =2x2 \pi rad/s=>4 \pi rad/s[/tex]

Generally the equation for Force applied is mathematically given by

 [tex]F =mrw2[/tex]

 [tex]F=0.15*0.6* (4*x3.14^)2[/tex]

 [tex]F = 14.2 N[/tex]    

When we exhale, 90% waste material is Carbon Dioxide ( CO2 ) , so, it gets exhaled out in the form of CO2 rich air and it gets removed from the body, therefore our internal body becomes more pure and helps in making our internal temperature constant at a suitable level.

Answer:

[b] it id heated from 4o

Explanation:

Answer:

The water usually rushes back too enthusiastically, causing a splash – and the bigger the rock, the bigger the splash. The splash then creates even more ripples that tend to move away from where the rock went into the water.

The correct answer is option B. Determine whether experimental observations can provide evidence to support a conclusion.

1. Identify the research question: Begin by clearly defining the question or problem that you want to investigate. This question should be specific and focused, allowing for clear hypotheses to be developed.

2. Conduct background research: Familiarize yourself with existing knowledge and previous research related to your question. This step will help you understand the current state of knowledge in the field and identify any gaps or areas that require further investigation.

3. Formulate a hypothesis: Based on your background research, develop a hypothesis that proposes a possible explanation or answer to your research question. A hypothesis should be a clear statement that can be tested through experimentation or observation. It should be specific, measurable, and falsifiable, meaning that it can be proven wrong if the evidence does not support it.

4. Design experiments or observations: Once you have formulated a hypothesis, consider the experimental or observational methods that can be used to test it. Determine what data you need to collect, what variables you need to manipulate or measure, and what controls should be put in place to ensure the validity of your results.

5. Predict outcomes: Based on your hypothesis, make predictions about the expected outcomes of your experiments or observations. These predictions should be derived from your hypothesis and should be specific enough to be tested.

6. Conduct the experiment or observation: Carry out the planned experiments or observations, ensuring that you collect and record data accurately. Implement proper controls and procedures to minimize any biases or confounding factors that could affect the results.

7. Analyze the data: Once you have collected the data, analyze it using appropriate statistical or analytical methods. Evaluate whether the data supports or contradicts your hypothesis and predictions.

8. Draw conclusions: Based on the analysis of your data, draw conclusions about whether the evidence supports or refutes your hypothesis. Clearly state the findings and discuss their implications in the context of the research question.

9. Communicate the results: Share your findings with the scientific community through scientific papers, presentations, or other appropriate means. Allow other scientists to review and replicate your work, fostering further discussion and advancement in the field.

Remember, the scientific process is iterative, and developing a hypothesis is just the starting point. Scientists continuously refine and revise their hypotheses based on new evidence and insights gained from their experiments and observations.

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Answer:

both swings at the same place

Explanation:

because there mother is giving same amount of force to both.

Answer:

D I think I’m not for sure

Explanation: