can someone help
pls !

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:

bc earth rotates

3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P3==D---------- :P

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:

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:

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:

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:

In this conversation the Neil astronaut is right

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:

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:

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

#SPJ6

Answer:

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

Answer: a downward pull on any object

Explanation:

Answer:

0.1 kg/s.

Explanation:

The density of water, d = 1000 kg/m³

Volume, V = 2 L

Time, t = 20 s

We need to find the mass flow rate from the faucet. We know that the density of an object is given by :

[tex]d=\dfrac{m}{V}\\\\m=d\times V\\\\\dfrac{m}{t}=\dfrac{dV}{t}\\\\\dfrac{m}{t}=\dfrac{1000\times 0.002}{20}\\\\=0.1\ kg/s[/tex]

So, the mass flow rate is equal to 0.1 kg/s.

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:

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:

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:

chemical bonds

Explanation:

because no energy is required

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:

[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:

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:

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:

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

This question involves the concept of semi-projectile motion. It can be solved using the equations of motion in the horizontal and the vertical motion.

The minimum horizontal velocity required is "2.6 m/s".

First, we will analyze the vertical motion of the stunt person. We will use the second equation of motion in the vertical direction to find the time interval for the motion.

[tex]h=v_it+\frac{1}{2}gt^2[/tex]

where,

h = height = 3 m

vi = initial vertical speed = 0 m/s

t = time interval = ?

g = acceleration due to gravity = 9.81 m/s²

therefore,

[tex]3\ m = (0\ m/s)(t) + \frac{1}{2}(9.81\ m/s^2)t^2\\\\t^2 = \frac{(3\ m)(2)}{9.81\ m/s^2}\\\\t = \sqrt{0.611\ s^2}[/tex]

t = 0.78 s

Now, we will analyze the horizontal motion. We assume no air resistance, so the horizontal motion will be uniform. Hence, using the equation of uniform motion here:

[tex]s = vt\\\\v = \frac{s}{t}[/tex]

where,

s = horizontal distance = 2 m

t =0.78 s

v = minimum horizontal velocity = ?

Therefore,

[tex]v = \frac{2\ m}{0.78\ s}[/tex]

v = 2.6 m/s

Learn more about equations of motion here:  

brainly.com/question/20594939?referrer=searchResults

The attached picture shows the equations of motion in the horizontal and vertical directions.

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:

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:

hi

Explanation:

answer is C

have a nice day