6th grade science!!!!!!!!!!​

Answer:

I’m. Nog sure

Explanation:

Answer:

In order to answer this question, you need the enthalpy of fusion of ice, which is 333.55 J/g (Joules/gram). The enthalpy of fusion is the amount of heat that must be absorbed or lost in order to change physical state.

The number of Joules required to melt the ice = enthalpy of fusion of ice x mass of ice.

1 kg = 1000g

40kg x (1000g/1kg) = 40,000g

Joules needed to melt the ice = 333.55 J/g x 40000 g = 13342000 J or

1.3342 x 107 J

Explanation:

Instead of 40kg input 50kg and get the answer

Answer:

7.5 units

13 units

Explanation:

[tex]|v|=5\ \text{units}[/tex]

[tex]|u|=3\ \text{units}[/tex]

[tex]\theta[/tex] = Angle between the vectors = [tex]60^{\circ}[/tex]

Scalar product is given by

[tex]u\cdot v=|u||v|\cos\theta\\ =3\cdot 5\cdot \cos60^{\circ}\\ =7.5\ \text{units}[/tex]

The scalar product of the vectors is 7.5 units.

Vector product is given by

[tex]u\times v=|u||v|\sin\theta\\ =3\times 5\sin60^{\circ}\\ =13\ \text{units}[/tex]

The vector product of the vectors is 13 units.

Answer: C: The moons orbit around the earth.

Explanation:

Answer:

D is the correct answer

Explanation:

Ek=m*g*h=50*9.8*5=2450

The kinetic energy right before she hits the water is 2450J. So, the correct option is D.

Kinetic energy is defined as the energy that is due to the motion of an object. If we want to accelerate an object, we must apply a force, by applying a force we need to do work. After the work is done, energy has been transferred to the object, and the object will continue to move with a new constant speed.

A 50Kg girl jumps off a 5-meter-high diving board.

We need to find the kinetic energy of the girl before she enters the water which means that the kinetic energy becomes equal to the potential energy such that,

P.E.=K.E. = mgh

where, m=mass of the object

g= acceleration due to gravity [tex](9.8m/s^2)[/tex]

h= height

So, K.E= 50* 9.8*5 = 2450 J

Thus, the kinetic energy right before she hits the water is 2450J. So, the correct option is D.

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Answer:

Total time elapsed between the start and when he returns with the ball is 7.5s

Explanation:

From the question,

- The dog starts at the origin and runs forward at 6m/s for 1.5s. First, we will determine the distance covered while running forward.

From

Speed = Distance / Time

Distance = Speed × Time

Speed = 6m/s

Time = 1.5s

∴ Distance = 6m/s × 1.5s

Distance = 9m

That is, the dog covered a distance of 9m while running forward.

- The dog turns around and runs backward at 7m/s for 3s. Now, we will also determine the distance the dog covered backwards.

Distance = Speed × Time

Speed = 7m/s

Time = 3s

Distance = 7m/s × 3s

Distance = 21m

The dog's displacement from the origin is 21m - 9m = 12m

Now, to calculate how much time has elapsed between the start if the dog runs back to the origin at 4m/s, we will first determine the time the dog spent back to the origin and then add to the time spent for the first two distances.

To get back to the origin, the dog needs to cover 12m

From

Speed = Distance / Time

Time = Distance / Speed

Distance = 12m

Speed = 4m/s

∴ Time = (12m) / (4m/s)

Time = 3s

Therefore, the dog spent 3s to run back to the origin.

Hence, total time elapsed = 1.5s + 3s + 3s

Total time elapsed = 7.5s

Answer:

[tex]1.1 \: \mathrm{m/s}[/tex]

Explanation:

The formula for average velocity is [tex]\frac{\Delta x}{\Delta t}[/tex], where [tex]\Delta x[/tex] = total displacement and [tex]\Delta t[/tex] = time.

Because velocity is usually given in meters per second, convert 6.0 miles to meters and 2.5 hours to seconds:

6.0 miles = [tex]9656.09\: \mathrm{meters}[/tex]

2.5 hours = [tex]9000 \: \mathrm{seconds}[/tex]

Therefore the average velocity of the person is [tex]\frac{9656.09}{9000} \approx 1.07 = \fbox{$1.1\: \mathrm{m/s}$}[/tex] (two significant figures).

Answer:

Explanation:

The Earth pulls the bicycle downward through the force of gravity, and, in response, the bicycle pulls up on the Earth with a force of equal magnitude. Gravity "pushes" the Earth into the road, which pushes up with an opposite force, canceling gravity. Thus, action reaction forces do not cancel each other.

The centripetal force is the force that keeps a body moving in a circular path.

The centripetal force is given by; F = mv^2/r

1) We have;

F = 5,600 N

v = 20 m/s

r =?

m = 700 kg

Making r the subject of the formula;

r =mv^2/F

r = 700 × (20)^2/5,600

r = 50 m

2) F = mv^2/r

F = 900 × (5)^2/30

F = 750 N

3) Making r the subject of the formula;

r =mv^2/F

r = 800 × (40)^2/ 16,000

r = 80 m

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Answer:

No work is done since no distance is given

Explanation:

Since no distance is given, the force is not doing any work

No work is done by the man since we do not know the distance or displacement.

Work is only said to be done when the force applied on an object moves it through a particular distance.

Work done  = Force x distance.

Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.

Answer:

Your tracker will detect your arm movement and will interpret it as steps so this is what it likely happening. Something similar happens while driving, if you go through a bumpy road or your car has a stiff suspension then this can cause the tracker to detect movement and count it as steps. Usually while driving and if you notice some vibration on your car or steering wheel you can try having your tracker a little bit more tight around your wrist and this will help decrease the amount of steps detected.

Explanation:

(Via AlvaroFitbit)

Answer:

[tex]F_T=60132.52N[/tex]

[tex]P=15814852.76W[/tex]

Explanation:

From the question we are told that

Velocity of aircraft  [tex]V=263m/s[/tex]

Engine air intake rate [tex]\triangle M_a=85.9kg/s[/tex]

Fuel burn rate  [tex]\triangle M_f =3.92kg/s[/tex]

Velocity of exhaust gas [tex]V_e =921m/s[/tex]

Generally the Mass change rate of Rocket is mathematically given by

 [tex]\triangle M = \triangle M_a+\triangle M_f[/tex]

 [tex]\triangle M= 85.9+3.92[/tex]

 [tex]\triangle M=89.82kg/s[/tex]

Generally the Trust of the rocket is given mathematically by

 [tex]F_T=(\triangle M *V_e)-(dM_a/dt)*(V)[/tex]

 [tex]F_T=(89.82 *921)-(85.9)*(263)[/tex]

 [tex]F_T=60132.52N[/tex]

Generally the Rocket's delivered power is mathematically given by

Delivered power P

 [tex]P=V*F_T[/tex]

 [tex]P=263*60132.52N[/tex]

 [tex]P=15814852.76W.[/tex]

Answer:

39225J

Explanation:

Given parameters:

Mass of water  = 375grams of water

Change in temperature  = 25°C

Specific heat capacity of water  = 4.184J/g°C

Unknown:

Amount of heat absorbed  = ?

Solution:

To solve this problem, we use the expression below:

      H  = m c Ф  

H is the heat absorbed

m is the mass

c is the specific heat capacity

Ф is the change in temperature

  Insert the parameters and solve;

      H  = 375 x 4.184 x (25) = 39225J

sorry i think so i dont exactly know i am sorry

Explanation:

As a certain amount of water is cooled from room temperature until it reaches 4 °C, its volume drops. The density reduces as the volume increases below 4 °C. Therefore, water's greatest density occurs at 4 degrees Celsius.

Water has an unusual trait called anomalous expansion, which causes it to enlarge rather than compress when the temperature drops from 4 °C to 0 °C, and it becomes less dense.

At temperatures not far below zero degrees Celsius, water ice is unique for having low coefficients of static and dynamic friction that range from 0.04-0.02, but as the temperature drops, these numbers rise.

Therefore, When a metal sheet's temperature rises by one degree, its coefficient of area expansion is calculated as the increase in surface area per unit of original surface area.

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Answer:

The energy that will go will for thermal store of the surroundings is 20 J.

Explanation:

Given;

kinetic of the thrown ball, K.E₁ = 50 J

kinetic energy used to move the target, K.E₂ = 30 J

The excess energy that will go will for thermal store of the surroundings;

ΔK.E = K.E₁ - K.E₂

ΔK.E = 50J - 30J

ΔK.E = 20 J

Therefore, the energy that will go will for thermal store of the surroundings is 20 J.

Explanation:

Given

heat supplied (Q) = 1000 J

mass(m) = 100 g = 0.1 kg

specific heat capacity of water(s) = 4200 J/kg°C

change in Temperature (dt) = ?

We know we have the relation

Q = m * s * dt

Or, 1000 = 0.1 * 4200 * dt

Or, 1000 = 420 dt

Or, dt = 1000/ 420

Therefore dt = 2.38°

Hope it will help :)

The temperature changes when 1000J of heat is supplied to 100g of water is dt = 2.38°

The average kinetic energy of a system is measured by its temperature. The kinetic energy of a system starts to rise as the particle's velocity increases, which raises the system's temperature.

The energy that is transferred when two bodies with different surface temperatures come in touch is referred to as heat.

The change is when 1000J of heat is supplied to 100g of water.

Given that:

heat supplied (Q) = 1000 J

mass(m) = 100 g = 0.1 kg

specific heat capacity of water(s) = 4200 J/kg°C

Change in Temperature (dt) = ?

We know we have the relation

Q = m x s x dt

Or, 1000 = 0.1 x 4200 x dt

Or, 1000 = 420 dt

Or, dt = 1000/ 420

Therefore, the temperature changes when 1000J of heat is supplied to 100g of water is dt = 2.38°.

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Answer:

Acceleration = 9.8m/s²

Explanation:

Given the following data;

Initial velocity = 0m/s (since it's starting from rest).

Final velocity, v = 14.7m/s

Time, t = 1.5 seconds.

To find acceleration;

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

[tex]Acceleration = \frac{v - u}{t}[/tex]

Substituting into the equation, we have;

[tex]Acceleration = \frac{14.7 - 0}{1.5}[/tex]

[tex]Acceleration = \frac{14.7}{1.5}[/tex]

Acceleration = 9.8m/s²

Therefore, the average acceleration of the golf ball is 9.8m/s².

Answer:

Explanation:

El campo eléctrico provocado por una carga puntal sobre determinado punto viene dado por la ecuación:

E  = K * Q /r²       en esa ecuación E es el campo eléctrico (un vector), K es una constante K = 1/4*π*ε₀   Q es la carga que origina el campo, y r la distancia entre la carga y el punto donde se quiere determinar el campo. La fuerza de origen eléctrico y el campo eléctrico van en la dirección de la recta de unión entre carga y punto ( es decir según r) y esta fuerza sera repulsiva o de atracción según que la carga que la origina sea positiva o negativa (respectivamente, ya que en la determinación de fuerza y campo, se asume que se coloca una carga de prueba positiva en el punto ).

Siendo así, si dos cargas elécticas son iguales y están separadas una distancia r ; en el punto medio (r/2) los campos producidos por cada una de las cargas serán de la misma magntud.

Carga Q₁  = Carga Q₂  = Q

E₁ = K * Q₁ / (r/2)²   y    E₂  = K * Q₂/(r/2)²

Y además tendran direcciones totalmente opuestas, por lo que se anularan

En el segundo caso las cargas son iguales en magntud pero de diferentes signos ( una positiva y la otra negativa ). En este caso los campos eléctricos continuaran siendo de la msma magnitud pero dado que la carga positiva repele la carga de muestra (teorica) y la negativa la atrae los dos campos coinciden en su dirección y resultará una campo de magnitud doble. La dirección del campo será en la tendencia de acercarse a la caga negativa, así si la carga negativa está a la derecha la fuerza de origen eléctrico y el campo van hacia la derecha y si la carga negativa está a la izquierda pues esa será la diercción del campo

Answer:

[tex]P=203.3819375kg.m/s\\P\approx203.4kg.m/s[/tex]

[tex]\theta=6.4541\textdegree North East\\\theta\approx6.5\textdegree North East[/tex]

Explanation:

From the question we are told that

Mass of first jogger [tex]M=69kg[/tex]

Speed[tex]v_1=1.6m/s[/tex]

Direction [tex]d= East[/tex]

Mass of 2nd jogger [tex]M=63kg[/tex]

Speed [tex]v_2=1.5m/s[/tex]

Direction [tex]d= 14\textdegree north[/tex]

Generally equation for momentum along the the horizontal is mathematically given as

[tex]P_x=m_1v_1 +m_2v_2cos\theta[/tex]

[tex]P_x=(69)*(1.6) +(63)*(1.5)cos14[/tex]

[tex]P_x=202.0929461kg.m/s[/tex]

Generally equation for momentum along the the vertical is mathematically given as

[tex]P_y=m_2v_2cos\theta[/tex]

[tex]P_x=22.86161913kgm/s[/tex]

a)Generally the magnitude of momentum is mathematically given by

[tex]P=\sqrt{(P_x)^2+(P_y)^2}[/tex]

[tex]P=\sqrt{(202.0929461)^2+(22.86161913)^2}[/tex]

[tex]P=\sqrt{41364.21249}[/tex]

[tex]P=203.3819375kg.m/s[/tex]

[tex]P\approx203.4kg.m/s[/tex]

b) Generally the angle [tex]\theta[/tex] is mathematically given by

[tex]\theta=tan^-^1\frac{py}{px} \\[/tex]

[tex]\theta=tan^-^1\frac{22.86161913}{202.0929461}[/tex]

[tex]\theta=tan^-^1(0.1131242805)[/tex]

[tex]\theta=6.4541\textdegree North East[/tex]

Answer:

W= F × d

W= 2kn × 3.6

W= 7.2 J

Work is measured in Joules!

Answer:

Condensation (((((((((((((

Answer:

b. at the top

Explanation:

At the top of the climb, the vertical velocity of Jeff's throw has a value of zero.

Vertical velocity in this instance is acting against the acceleration due to gravity.

Complete question :

A flight attendant pulls her 70 N flight bag a distance of 318 m along a level airport floor at a constant velocity. The force she exerts is 41 N at an angle of 57° above the horizontal.

(a) Find the work she does on the flight bag.

(b) Find the work done by the force of friction on the flight bag.

(c) Find the coefficient of kinetic friction between the flight bag and the floor.

Answer:

7107 J ; - 7107 J ; 0.55

Explanation:

Given that :

Distance, d = 318m

Applied force = 41 N

θ = 57°

A.) Workdone = Force exerted along direction of motion

Workdone = applied Force * distance * cosθ

Workdone = 41 * 318 * cos57 = 7101.0037

Workdone = 7,101 J

B.) Workdone by force of friction on flight bag:

- 7,101 J (since the body moves at constant velocity)

C.)

Coefficient of kinetic friction (μ) = Frictional force / normal reaction)

μ = F / N

Frictional force, F = Workdone by friction / distance

F = 6200 / 318

F = 19.47N ;

Ff = weight of Flight bag = 70 N

N = Ff - Fsinθ

N = 70 - applied Force sinθ

N = 70 - 41sin57

N = 70 - 34.385493

N = 35.614506

μ = 19.47 / 35.614506

μ = 0.5466873

Answer:

The answer is C.

Explanation:

because if you look ay the nutrons you can see that it adds to the protons

Answer:

C

Explanation:

Isotopes of Chlorine (Cl) gain an electron when they form ionic bonds. This results in a negative ion (the Chloride ion). ... When the charge on an atom is zero it means the number of protons is equal to the number of electrons. The atom is said to be neutral and there will not be a + or - written after the element symbol.

Answer:

1.  -0.863 kgm/s 2. -1.438 kgm/s

Explanation:

1. What is the change in momentum of the bullet if it embeds in the block?

Since the block does not move, the velocity of the bullet after hitting the block , v is zero. That is v = 0 m/s

Now, the momentum change of the bullet ΔP = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = 0 m/s (since it embeds in the block and the block does not move).

So, ΔP = m(v - u)

= 5.75 × 10⁻³ kg(0 m/s - 1.50 × 10² m/s)

= 5.75 × 10⁻³ kg(- 1.50 × 10² m/s)

= -8.625 × 10⁻¹ kgm/s

= -0.8625 kgm/s

≅ -0.863 kgm/s

2. What is the change in momentum of the bullet if it bounces off the block in the opposite direction with a speed of 100 m/s?

If it bounces off the block in the opposite direction with a speed of 100 m/s, then its final velocity is v = -100 m/s.

So, our momentum change ΔP' = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = -100 m/s = -1 × 10² m/s

So, ΔP = m(v - u)

= 5.75 × 10⁻³ kg(-1 × 10² m/s - 1.50 × 10² m/s)

= 5.75 × 10⁻³ kg(-2.50 × 10² m/s)

= -14.375 × 10⁻¹ kgm/s

= -1.4375 kgm/s

≅ -1.438 kgm/s

Answer:

[tex]75\:\mathrm{seconds}[/tex]

Explanation:

The impulse-momentum theorem states that the impulse of an object is equal to the change in momentum of that object:

[tex]\Delta p=m\Delta v[/tex].

Impulse is also given by [tex]F\Delta t[/tex] where [tex]F[/tex] is the average net force and [tex]\Delta t[/tex] is change in time.

Therefore, we can set both equations equal to each other and solve:

[tex]\Delta p= F\Delta t[/tex].

Assuming that the airplane was initially at rest, its change in momentum is:

[tex]\Delta p =m\Delta v,\\\Delta p=30,000\cdot 50=1,500,000[/tex]

Impulse is represented using [tex]Ns[/tex]. Therefore, convert [tex]20\:\mathrm{kN}[/tex] to Newtons:

[tex]20\:\mathrm{kN}=20,000\:\mathrm{N}[/tex]

Thus:

[tex]1,500,000=20,000\cdot t,\\t=\frac{1,500,000}{20,000}=\fbox{$75\mathrm{s}$}[/tex].

Naw ur pretty accurate, heck collage is the only football worth watching most the time. Hook'um horns!

Answer:

An object at rest is described by Newton's First Law of Motion. An object in static equilibrium has zero net force acting upon it. The First Condition of Equilibrium is that the vector sum of all the forces acting on a body vanishes.

Explanation:

Answer:

see below

Explanation:

the first condition means that the light ray inside the optically denser medium hits the surface of the optically less dense medium.

this in simple words means, light must be travelling from am optically denser medium to an optically less dense medium

hope this helps :)

Answer:

B is the difference قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *