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3 years ago

Really need help with this Physics question!

Physics

1 answer:

mojhsa [17]3 years ago

8 0

As we know that block of steel is continue to be in moving state

so here the friction must be kinetic friction between two surface

so we know that formula of kinetic friction must be

$F_k = \mu_k mg$

now we have

$\mu_k = 0.57$

$mg = 25 N$

now from the above equation we have

$F_k = 0.57\times 25$

$F_k = 14.25 N$

So here we need atleast 14.25 N force to continue sliding the box now as per given options all forces which are less than 14.25 N is not correct

Hence correct answer must be 18.0 N

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A 20 cm-long wire carrying a current of 6 A is immersed in a uniform magnetic field of 3 T. If the magnetic field is oriented at

SOVA2 [1]

Answer:

the magnitude of the force that the wire will experience = 1.8 N

Explanation:

The force on a current carrying wire placed in a magnetic field is :

F = Idl × B

where:

I = current flowing through the wire

dl = length of the wire

B = magnetic field

We can equally say that :

$|F| = IdlBsin \theta$

where : sin θ is the angle at which the orientation from the magnetic field to the wire occurs = 30°

Then;

$|F| = B\ I \ L \ sin \theta$

Given that:

L = 20 cm = 0.2 m

I = 6 A

B = 3 T

θ = 30°

Then:

F = 3 × 6 × 0.2 sin 30°

F = 1.8 N

Therefore, the magnitude of the force that the wire will experience = 1.8 N

6 0

3 years ago

A square loop of side 7 cm is placed with the nearest side 2 cm from a long wire carrying a current that varies with time at a c

ioda

Answer:

Explanation:

side of the square loop, a = 7 cm

distance of the nearest side from long wire, r = 2 cm = 0.02 m

di/dt = 9 A/s

Integrate on both the sides

$\int _{0}^{i}di =9\int _{0}^{t}dt$

i = 9t

(a) The magnetic field due to the current carrying wire at a distance r is given by

$B = \frac{\mu_{0}i}{2\pi r}$

$B = \frac{\mu_{0}\times 9t}{2\pi r}$

(b)

Magnetic flux,

$\phi=\int B\times a dr$

$\phi=\int \frac{\mu_{0}\times 9t}{2\pi r}\times a dr$

$\phi=\frac{\mu_{0}\times 9t\times a}{2\pi}\times ln\left ( \frac{2 + 7}{2} \right )$

$\phi=\frac{\mu_{0}\times 9t\times 0.07}{2\pi}\times ln(4.5)$

$\phi = 1.89 \times 10^{-7}t$

(c)

R = 3 ohm

$e = -\frac{d\phi}{dt}$

magnitude of voltage is

e = 1.89 x 10^-7 V

induced current, i = e / R = (1.89 x 10^-7) / 3

i = 6.3 x 10^-8 A

8 0

3 years ago

Standing waves can ruin the acoustics of a concert hall if there is excessive reflection of the sound waves that the performers

Dmitrij [34]

Answer:

The answer to the questions is;

In terms of standing waves, the listener moves from a location with high amplitude to one with lower amplitude or vibration (anti-node to node)

The distance 4.1 cm is equivalent to λ/4

Explanation:

For standing waves we have is a stationary wave comprising of two opposite direction moving waves that have equal amplitude and frequency, resulting in the superimposition of the waves. As such certain points are fixed along the wave path that is the peaks amplitude of the wave oscillation is constant at a particular point. A node occurring at a point and an anti-node occurring at another fixed point

When the listener moves 4.1 cm he or she has left the anti-node to the node hence the faintness of the sound

The distance from the node to the anti-node is 1/4 wavelength, or 1/4×λ

Therefore 4.1 cm is λ/4

6 0

3 years ago

What the name for the phenomenon of inducing voltage by changing the magnetic field around a conductor?

8090 [49]

The phenomenon of inducing voltage by changing the magnetic field around a conductor will be Electromagnetic Induction. Option B is correct.

<h3>What is the Faraday law of electromagnetic induction?</h3>

According to Faraday's law of electromagnetic induction, the rate of change of magnetic flux link with the coil is responsible for generating emf in the coil to result in the flow of amount of current .

So in order to increase the current, we need to increase the EMF;

so we can increase it by;

1) Increasing the number of turns

2) Increase the area of the loop

3) By moving the magnet faster

Hence, option B is correct.

To learn more about Faraday law of electromagnetic induction:

brainly.com/question/13369951

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8 0

2 years ago

Determine e when I = 0.50 A and R = 12 W.