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Answer:

In this conversation the Neil astronaut is right

Answer:

Wax melts as it absorb heat from flame

Explanation:

To know which option is correct, it is important that we know what chemical changes and physical changes are all about.

Chemical change is a change in which the process is not easily reversed and it produces new substance.

Physical change is more like the opposite of chemical change. In this change, the process is easily reversed and no new substance is produced.

Considering the options given above,

1. Iron combines with oxygen to produce rust is a chemical change since a new substance (rust) is formed and we can not reverse the process to get back iron and oxygen.

2. Wax melts as it absorb heat from flame is a physical change since no new substance is formed and we obtained the wax by allowing it to solidified.

3. Pure sodium explodes when dropped in water is a chemical change because we can not reverse the process to get back the sodium.

4. Glucose molecules are produced in plant leaf is also a chemical change.

From the illustrations above, it is evident that: 'Wax melts as it absorb heat from flame' is not a chemical

Answer:

a = -3984.6 m/s²

F = 577.76 N

Explanation:

The acceleration of the ball can be calculated by using the third equation of motion:

[tex]2as = v_f^2 - v_i^2\\[/tex]

where,

a = acceleration of ball = ?

s = distance covered = recoil distance = 0.135 m

vf = final speed = 0 m/s

vi = initial speed = 38.2 m/s

Therefore,

[tex]2(0.135\ m)a = (0\ m/s)^2-(38.2\ m/s)^2\\[/tex]

a = -3984.6 m/s²

here negative sign shows deceleration.

Now, for the force applied by Brian Lara will be equal in magnitude but opposite in direction of the force required to stop the ball:

[tex]F = -ma\\F = -(0.145\ kg)(-3984.6\ m/s^2)\\[/tex]

F = 577.76 N

Answer: The bell has 8550 J energy.

given, There is a bell at the top of a tower that is 45 m high. The bell weighs 190 N

i.e., bell is located at the top of tower, h = 45m

weight of the bell, F = 190 N

workdone by the gravitational force = F.hcos180°

[ gravitational force (i.e., weight ) acting downward while body is located 45m above the ground. so, angle between force and h = 180° ]

workdone by the gravitational force = 190 × 45 × (-1)

= -8550 J

we know, potential energy = negative of workdone

= -(-8550 J) = 8550 J

Answer:

200,000J

Explanation:

KE= 0.5 x m x v^2

KE= 0.5x1000x20^2

KE= 0.5 x 1000 x 400

KE= 500 x 400

KE= 200,000

Answer:

car B will be 30 Km ahead of car A.

Explanation:

We'll begin by calculating the distance travelled by each car. This is illustrated below:

For car A:

Speed = 40 km/h

Time = 3 hours

Distance =?

Speed = distance / time

40 = distance / 3

Cross multiply

Distance = 40 × 3

Distance = 120 Km

For car B:

Speed = 50 km/h

Time = 3 hours

Distance =?

Speed = distance / time

50 = distance / 3

Cross multiply

Distance = 50 × 3

Distance = 150 Km

Finally, we shall determine the distance between car B an car A. This can be obtained as follow:

Distance travelled by car B (D₆) = 150 Km

Distance travelled by car A (Dₐ) = 120 Km

Distance apart =?

Distance apart = D₆ – Dₐ

Distance apart = 150 – 120

Distance apart = 30 Km

Therefore, car B will be 30 Km ahead of car A.

Answer:

Subduction , Latin for "carried under," is a term used for a specific type of plate interaction. It happens when one lithospheric plate meets another—that is, in convergent zones —and the denser plate sinks down into the mantle.

Answer:

chemical bonds

Explanation:

because no energy is required

Answer:

hi

Explanation:

answer is C

have a nice day

Answer:

have a component along the direction of motion that remains perpendicular to the direction of motion

Explanation:

In this exercise you are asked to enter which sentence is correct, let's start by writing Newton's second law.

circular movement

          F = m a

          a = v² / r

          F = m v²/R

where the force is perpendicular to the velocity, all the force is used to change the direction of the velocity

in linear motion

         F = m a

where the force is parallel to the acceleration of the body, the total force is used to change the modulus of the velocity

the correct answer is: have a component along the direction of motion that remains perpendicular to the direction of motion

Answer:

e = 0.0898m

v = 2.07m/s

Explanation:

a) According to Hooke's law

F = ke

e is the extension

k is the spring constant

Since F = mg

mg = ke

e = mg/k

Substitute the given value

e = 1.1(9.8)/120

e = 10.78/120

e = 0.0898m

Hence it is stretched by 0.0898m from its unstrained length

2) Total Energy = PE+KE+Elastic potential

Total Energy = mgh +1/2mv²+1/2ke²

Substitute the given value

5.0= 1.1(9.8)(0.2)+1/2(1.1)v²+1/2(120)(0.0898)²

Solve for v

5.0 = 2.156+0.55v²+0.48338

5.0-2.156-0.48338= 0.55v²

2.36 =0.55v²

v² = 2.36/0.55

v² = 4.29

v ,= √4.29

v = 2.07m/s

Hence the required velocity is 9.28m/s

Answer:

No, the mass will never come to rest

Explanation:

It is so because even at arbitrarily small distance it will experience some amount of force (irrespective of how small the value of force is).

This does not allow the mass to become stationary or in a equilibrium state as it is still subject to some amount of force.

Hence, the the mass will never come to rest

Answer:

Explanation:

Physics is the branch of science that studies the natural world and its rules and orders. It is one of the oldest sciences as ancient people study the stars and astronomy is considered part of Physics.

Answer:

500 Hz

Explanation:

Formula for finding wave frequency is,

f = c/λ

f = frequency

c = speed (m/s)

λ = wave length (m)

f = c/λ

f = 280/0.56

f = 500

∴ wave frequency is 500 Hz

Answer:

T

beacuse:

Energy can be transferred from one object to another by doing work. ... When work is done, energy is transferred from the agent to the object, which results in a change in the object's motion (more specifically, a change in the object's kinetic energy).

Answer:

[tex]0.475\ \text{V}[/tex]

Explanation:

n = Number of turns = 10

r = Radius = 1.5 cm

I = Current = 10 A

t = Time = [tex]6.25\times 10^{-6}\ \text{s}[/tex]

[tex]\mu_0[/tex] = Vacuum permeability = [tex]4\pi\times 10^{-7}\ \text{H/m}[/tex]

Magnetic field is given by

[tex]B=\dfrac{\mu_0I}{2r}\\\Rightarrow B=\dfrac{4\pi 10^{-7}\times 10}{2\times 1.5\times 10^{-2}}\\\Rightarrow B=0.00042\ \text{T}[/tex]

EMF is given by

[tex]\varepsilon=\dfrac{nBA}{t}\\\Rightarrow \varepsilon=\dfrac{10\times 0.00042\times \pi (1.5\times 10^{-2})^2}{6.25\times 10^{-6}}\\\Rightarrow \varepsilon=0.475\ \text{V}[/tex]

The average induced emf is [tex]0.475\ \text{V}[/tex].

Answer:

It is the force that pulls down an object on the air

Answer: a downward pull on any object

Explanation:

Answer:

t = 9.52 s

Explanation:

This is an oscillatory motion exercise, in which the angular velocity is

         w = [tex]\sqrt{ \frac{k}{m} }[/tex]

Let's use hooke's law to find the spring constant, let's write the equilibrium equation

        F_e - W = 0

        F_e = W

        k x = m g

        k = [tex]\frac{m g}{x}[/tex]

        k = 0.545 9.8 /0.0356

        k = 150 N / m

now the angular velocity is related to the period

          W = 2π / T

we substitute

          4π² T² = k /m

          T = 4pi² [tex]\sqrt{ \frac{m}{k} }[/tex]

we substitute

           T = 4 pi² [tex]\sqrt{ \frac{0.545}{150} }[/tex]

            T = 2.38 s

therefore for the spring to oscillate 4 complete periods the time is

            t = 4 T

            t = 4 2.38

            t = 9.52 s

Answer:

D. Electrons are tightly bound to the nuclei.

Explanation:

In an insulator, the electrons of the outer most shell are bound with a very high electrostatic forces coming from the nucleus of each atom so electrons cannot flow around all atoms making up the material as in a conductor.

The characteristic of a good insulator is Electrons are tightly bound to the nuclei. (option d)

In a good insulator, electrons are tightly bound to the nuclei of their atoms. This means that they are not free to move around within the material, unlike conductors where electrons are relatively loosely bound and can move freely. Due to this strong binding, electrons in insulating materials cannot carry an electric charge or energy easily from one atom to another.

When an electric field is applied to an insulator, the electrons may experience a small displacement within their respective atoms, but they generally do not move from one atom to another or flow through the material like they would in a conductor. As a result, insulators prevent the flow of electric current and are used to isolate or protect conductive elements from accidental contact.

So, the correct answer is D. Electrons are tightly bound to the nuclei.

To know more about insulator here

https://brainly.com/question/2619275

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Initially, the energies are:

[tex]U_{i}=-\frac{G M_{\varepsilon} m}{r_{e}} \\ =K_{i}=\frac{1}{2} m v_{0}^{2}[/tex]

At final point, the energies are:

[tex]U_{f}=-\frac{G M_{\varepsilon} m}{r_{e}+h} \\ K_{f}=\frac{1}{2} m(0)^{2}=0[/tex]

Using conservation law of energy,

[tex]-\frac{G M_{e} m}{r_{e}}+\frac{1}{2} m v_{0}^{2} &=-\frac{G M_{e} m}{r_{\varepsilon}+h} \\ -\frac{G M_{e}}{r_{e}}+\frac{v_{0}^{2}}{2} &=-\frac{G M_{e}}{r_{e}+h} \\ \frac{-2 G M_{e}+r_{e} v_{0}^{2}}{2 r_{e}} &=-\frac{G M_{e}}{r_{e}+h} \\ \frac{r_{e}+h}{G M_{e}} &=\frac{2 r_{e}}{2 G M_{e}-r_{e} v_{0}^{2}}[/tex]

The equation is further simplified as:

[tex]r_{e}+h &=\left(\frac{2 r_{e}}{2 G M_{e}-r_{e} v_{0}^{2}}\right) G M_{e} \\ h &=\frac{2 r_{e} G M_{e}}{2 G M_{e}-r_{e} v_{0}^{2}}-r_{e} \\ &=\frac{2 r_{e} G M_{e}-2 r_{e} G M_{e}+r_{e}^{2} v_{0}^{2}}{2 G M_{e}-r_{e} v_{0}^{2}} \\ & h=\frac{r_{e}^{2} v_{0}^{2}}{2 G M_{e}-r_{e} v_{0}^{2}}[/tex]

Answer:

ωf = 113.95 rev/s

t = 1.26 s

Explanation:

We can use the third equation of motion to find out the final spinning speed of the wheel:

[tex]2\alpha \theta = \omega_f^2 -\omega_i^2\\[/tex]

where,

α = angular acceleration = 65 rev/s²

θ = No. of revolutions completed = 92 rev

ωf = final angular speed = ?

ωi = initial angular speed = 32 rev/s

Therefore,

[tex](2)(65\ rev/s^2)(92\ rev) = \omega_f^2 - (32\ rev/s)^2\\\omega_f^2 = 11960\ rev^2/s^2 + 1024\ rev^2/s^2\\\omega_f = \sqrt{12984\ rev^2/s^2}[/tex]

ωf = 113.95 rev/s

Now, for the time we can use the first equation of motion:

[tex]\omega_f = \omega_i +\alpha t\\113.95\ rev/s - 32\ rev/s = (65\ rev/s^2)t\\t = \frac{81.95\ rev/s}{65\ rev/s^2}\\\\[/tex]

t = 1.26 s

Answer:

bc earth rotates

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Explanation:

Answer:

The interaction between the solar wind and Earth's magnetic field, and the influence of the underlying atmosphere and ionosphere, creates various regions of fields, plasmas, and currents inside the magnetosphere such as the plasmasphere, the ring current, and radiation belts.

Explanation:

Answer:

e)  A changing magnetic field produces an electric field.

Explanation:

Ok, we start with a magnetic field and let's study how it affects the motion of a single electron. As the magnetic field changes, it will cause an electromotive force, that moves the electron, and because now we have a moving electron, now we will have an electric field. (Such that the direction of the electromotive force opposes the direction in which the magnetic field changes). This also can be deduced if we look at the third Maxwell's equation:

dE/dx = -dB/dt

This says that the spatial change in an electric field depends on how the magnetic field changes as time pass.

Then the correct option is e)  A changing magnetic field produces an electric field.

Answer:

B = 1.37 mT

Explanation:

Given that,

The magnitude of the electric field, E = 480 N/C

The speed of the proton, [tex]v=3.50 \times 10^5\ m/s[/tex]

We need to find the magnitude of the magnetic field. In a velocity selector, the electric field is balanced by the magnetic field. So,

[tex]qE=qvB[/tex]

Where

B is the magnetic field

[tex]B=\dfrac{E}{v}\\\\B=\dfrac{480}{3.5\times 10^5}\\\\B=1.37\times 10^{-3}\ T\\\\or\\\\B =1.37\ mT[/tex]

So, the magnetic field is equal to 1.37 mT.

Answer:

The neutral atom becomes an anion.

Explanation:

When a neutral atom gains an electron (e−), the number of protons (p+) in the nucleus remains the same, resulting in the atom becoming an anion (an ion with a net negative charge).

Answer:

They are right.

Explanation:

Answer:

Mechanical Energy : KE + PE

Conversion : "When energy transfers from one form to another"

Potential Energy: the energy possessed by a body by virtue of its position relative to others , stresses within itself, electric charge , and other factors .'

Kinetic Energy: energy of an object in motion

Law of conservation of energy: KE+PE+friction=KE

Explanation:

First of all mechanical energy is kinetic energy plus potential energy (it is the energy of movement) So:

Mechanical Energy : KE + PE

Conversion is when energy converts or becomes a different form. So:

Conversion : "When energy transfers from one form to another"

Potential energy is stored energy, in Physics I or AP Physics I, it is often due to it being at a height, but batteries, foods, etc. are also example of it, so:

Potential Energy: the energy possessed by a body by virtue of its position relative to others , stresses within itself, electric charge , and other factors .'

Kinetic energy is for objects in motion so you got it right!

Kinetic Energy: energy of an object in motion

The law of conservation of energy means there is the same amount of energy before, as there is after, so when you see an equation with energy on both sides, it is usually this. Also, this is the last question left, so this has to be the answer.

Law of conservation of energy: KE+PE+friction=KE

Answer:

Because the forces acting on the student are creating a net force.

Explanation:

I took the test and that was the answer

Answer:

Because the forces acting on the student are creating a net force

Explanation: