Can someone please help?

Answer:

An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The poles of an electromagnet can even be reversed by reversing the flow of electricity.

Answer:

2s

Explanation:

Given parameters:

Distance  = 30m

Speed  = 15m/s

Unknown:

Time before Laurence caught it = ?

Solution:

To solve this problem;

    Speed  = [tex]\frac{disance }{time}[/tex]  

 Time taken  = [tex]\frac{distance }{speed }[/tex]   = [tex]\frac{30}{15}[/tex]  = 2s

The time it takes is 2s

Given:

We will solve:

Speed  = [tex]\frac{distance}{time}[/tex]

Time taken  = [tex]\frac{distance}{time}[/tex] = [tex]\frac{30m}{15m/s}[/tex] = 2s

The time it takes is 2s

Answer:

930 centimeters

Explanation:

Answer:

Nervous system and immune system

Explanation:

The nervous system is involved because you immediately jumped away, that ur brain and nerves initiating the fight or flight response. The immune system is involved because the tack most likely pierced your skin, so your immune system needs to work to make sure the wound does not get infected.

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:

its either A or D

Explanation:

They use foam walls in like asylums but in the movies all the bad guys say "They can't hear you the metal is too thick" so its either one of those, hope it helped

Sound absorbing foams are typically softer and more lightweight than their sound blocking counterparts. This open and flexible cell structure acts as a natural soundwave absorber and prevents noises from reverberating off hard surfaces like walls, floors and ceilings.

"A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords."

"Sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain."

Sound is defined as vibrations that travel through air or another medium that can be heard when they reach a person's or animal's ears. Noise is defined as unwanted sound. In engineering, noise has the additional connotation of signals varying over time without meaning, whereas sound connotes meaningful signals.

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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:

The magnitude of the final velocity is approximately 0.526 m/s in approximately the direction of 8.746° East of South

Explanation:

The given collision parameters are;

The kind of collision experienced by the four velcro-lined air-hockey disk = Inelastic collision

The mass of the first disk, m₁ = 50.0 g

The velocity of the first disk, v₁ = 0.80 m/s West = -0.8·i

The mass of the second disk, m₂ = 60.0 g

The velocity of the second disk, v₂ = 2.50 m/s North = 2.5·j

The mass of the third disk, m₃ = 100.0 g

The velocity of the third disk, v₃ = 0.20 m/s East = 0.20·i

The mass of the fourth disk, m₄ = 40.0 g

The velocity of the fourth disk, v₄ = 0.50 m/s South = -0.50·j

Therefore, the total initial momentum of the four velcro-lined air-hockey disk, [tex]\Sigma P_{initial}[/tex] is given as follows;

[tex]\Sigma P_{initial}[/tex] = m₁·v₁ + m₂·v₂ + m₃·v₃ + m₄·v₄ = 50.0×(-0.80·i) + 60.0×(2.50·j) + 100 × (0.20·i) + 40.0 × (-0.50·j)

∴ [tex]\Sigma P_{initial}[/tex] = -40·i + 150·j + 20·i - 20·j = -20·i + 130·j

∴ [tex]\Sigma P_{initial}[/tex] = -20·i + 130·j

By the law of conservation of linear momentum, we have;

[tex]\Sigma P_{initial} = \Sigma P _{final}[/tex] = -20·i + 130·j

Therefore, given that the collision is perfectly inelastic, the disks move as one after the collision and the four masses are added to form one mass, "m", m = m₁ + m₂ + m₃ + m₄ = 50.0 + 60.0 + 100.0 + 40.0 = 250.0

∴ m = 250.0 g

Let, "v" represent the final velocity of the four disks moving as one after the collision

We have;

[tex]\Sigma P _{final}[/tex] = m × v = 250.0 × v = -20·i + 130·j

∴ v = -20·i/250 + 130·j/250 = -0.08·i + 0.52·j

The final velocity of the four disks after collision, v = -0.08·i + 0.52·j

The magnitude of the final velocity, [tex]\left | v \right |[/tex] = √((-0.08)² + (0.52)²) ≈ 0.526

[tex]\left | v \right |[/tex] ≈ 0.526 m/s

The direction of the final velocity, θ = arctan(0.52/(-0.08)) ≈ -81.254°

The direction of the final velocity, θ ≈ -81.254° which is 8.746° East of South

Answer:

52.802

Explanation:

"Significant figures" in Mathematics refer to the digits that give accuracy to the value of a measurement. There are specific rules when it comes to determining the significant figures. For example, all non-zero digits are considered significant and zeroes located in-between non-zero numbers are significant. In the number given above, the digit "0" is located between "8" and "1," therefore, it is significant. All the digits above are significant.

The problem is only asking for "five" significant figures. We can do this by counting from the left to the right. By this means, we know that the number will be rounded off to the nearest thousandths, which is "1." The number after 1 is 5, which means that 1 digit will be added to number 1, thus, making the digit into "2." The last digit (5) will then be removed.

Explanation:

five significant of 52.8015=52.801 ..

Answer:

KITTEEENNSSSSS last one is what i got for critsmas KlikBot Hexagon Special Pack

Explanation:

Answer:

The weight is 7.5 N

Explanation:

Since the rod is uniform, its weight applies downwards at its middle (i.e 50 cm mark). The diagram attached to this answer shows the appropriate sketch.

Applying the principle of moment to the question, let the weight by represented by W.

Total clockwise moment = Total counterclockwise moment

[tex]F_{1}[/tex] x [tex]d_{1}[/tex] = [tex]F_{2}[/tex] x [tex]d_{2}[/tex]

5 x 0.3 = W x 0.2

1.5 = 0.2 W

W = [tex]\frac{1.5}{0.2}[/tex]

   = 7.5 N

The value of the weight is 7.5 N.

Answer:

9J

Explanation:

Given parameters:

Mass of cell phone  = 80g

          1000g  = 1kg

            80g is therefore 0.08kg

Velocity of the cellphone  = 15m/s

Unknown:

Kinetic energy of the cellphone  = ?

Solution:

The kinetic energy of a body is the energy due to its motion.    

 It is expressed as:

    K.E  = [tex]\frac{1}{2}[/tex] mv²   =  [tex]\frac{1}{2}[/tex]  x 0.08 x 15²   = 9J

Answer: It’s fiber optics so B

The correctly lists the three features shown in the photo is folds, strike-slip faults, and anticlines.

Modern folds are those that emerged recently (on the scale of geological periods), that is, in the Tertiary Period (between 65 million and 2.5 million years ago). Faults are geological structures that originate from vertical (top-down) or inclined internal forces.

The transcurrent fault – also called horizontal fault – occurs when there is displacement in the horizontal plane between the two blocks, being more common in zones where two tectonic plates meet, when these also move horizontally.

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Answer: folds, strike-slip faults, and anticlines. (A)

Explanation: Got it right on my exam on Edge.

Answer:

(a) The length of the stretched string is approximately 42.53846 cm

(b) The elastic potential energy stored in the string is approximately 0.073877 Joules

Explanation:

(a) The given parameter are;

The force constant of the vertical spring, k = 26 N/m

The relaxed length of the spring, L = 35 cm = 0.35 m

The mass attached to the end of the spring, m = 200 g = 0.2 kg

By Hooke's law, we have;

F = k·x

Where;

F = The applied force on the sting = The weight of the attached mass, W

∴ F = W

The weight of the attached mass, W = m × g

Where;

g = The acceleration due to gravity ≈ 9.8 m/s²

Therefore, F = W = 0.2 kg × 9.8 m/s² = 1.96 N

From Hooke's law, we have;

x = F/k = 1.96 N/(26 N/m) ≈ 0.0753846 m

The extension of the stretched spring, x ≈ 0.0753846 m

The length of the stretched string, L[tex]_{stretched}[/tex] = L + x

∴ L[tex]_{stretched}[/tex] ≈ 0.35 m + 0.0753846 m ≈ 0.4253846 m

0.4253846 m = 42.53846 cm

The length of the stretched string ≈ 42.53846 cm

(b) The elastic potential energy stored in the string, U = 1/2·k·x²

By substituting the known values, we get;

U = 1/2 × 26 N/m × (0.0753849 m)² ≈ 0.073877 Joules

Answer:

A 20 Hz sound wave is 75 m long in the water (1500/20 = 75) whereas a 20 Hz sound wave in air is only 17 m long (340/20 = 17) in air. As we descend below the surface of the sea, the speed of sound decreases with decreasing temperature.

Answer:

Because both monomers and polymers and cross linked polymers are mers with physically properties which is good for applycations

Explanation:

because they are good for using and not using

also, this is a 5 point question, you are not  fooling anyone. thx for 5 points tho

Answer:

[tex]\boxed {\boxed {\sf 12 \ Newtons }}[/tex]

Explanation:

Force is equal to the product of mass and acceleration.

[tex]F=m*a[/tex]

We know the mass, but not the acceleration. Therefore, we must calculate it before we can calculate force.

1. Calculate Acceleration

Acceleration is the change in velocity over the change in time.

[tex]a=\frac{V_f-V_i}{t}[/tex]

The final velocity is 10 meters per second and the initial velocity is 4 meters per second. The time is 1 second.

[tex]V_f=10 \ m/s \\V_i= 4 \ m/s \\t= 1 \ s[/tex]

Substitute the values into the formula.

[tex]a=\frac{10 \ m/s-4 \ m/s }{1 \ s}[/tex]

Solve the numerator.

[tex]a=\frac{6 \ m/s}{1 \ s }[/tex]

Divide.

[tex]a= 6 \ m/s/s=6 \ m/s^2[/tex]

2. Calculate Force

Now we know the acceleration and the mass.

[tex]m= 2 \ kg \\a= 6 \ m/s^2[/tex]

Substitute the values into the fore formula.

[tex]F= 2 \ kg * 6 \ m/s^2[/tex]

Multiply.

[tex]F= 12 \ kg*m/s^2[/tex]

[tex]F= 12 \ N[/tex]

The force applies to the ball was 12 Newtons.

The question is incomplete. The compete question is :

Margaret Mary, Doug , and Kako are at a local amusement park. They see an attraction called the Giant Slide, which is simply a very long and high inclined plane. Visitors at the amusement park climb a long flight of stairs to the top of the 27inclined plane and are given canvas sacks. They sit on the sacks and slide down the plane 70m long. At the time when the three friends walked past the slide, a 135-kg man and a 20-kg boy are each at the top preparing to slide down. "I wonder how much less time it will take the man to slide down than it will take the boy," said Margaret Mary. "I think the boy will take less time," said Doug. "You're both wrong,"said Kako. "They will reach the bottom at the same time."

If the man and the boy do not take the same amount of time to reach the bottom of the slide, calculate how many seconds of difference there will between the two times.

Solution :

From body sliding down an incline plane, the acceleration is given by, [tex]$a = g \sin \theta$[/tex]

Since the body slides from rest, the initial velocity is, u = 0

Now the equation of motion, we have

        v= u + at

or     v = 0 +at

or      v = at

or     [tex]$t=\frac{v}{a}$[/tex] ............(1)

again we have, [tex]$v^2 -u^2 =2as $[/tex]

                         or [tex]$v = \sqrt{2s g \sin \theta} $[/tex]

Then from equation (1), we have

[tex]$t=\frac{\sqrt{2sg \sin \theta}}{g \sin \theta}$[/tex]

Thus this means that the time of sliding down an inclined plane does not depend on the mass of the body that slides.

Therefore, Kako is correct.

Since the time taken to slide an inclined plane is same for both the man and the boy, there is no difference between their time of sliding.

Answer:

Acceleration = 0.5 m/s²

Explanation:

Given the following data;

Initial velocity, u = 1m/s

Final velocity, v = 3m/s

Time, t = 4 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]a = \frac{v - u}{t}[/tex]

Substituting into the equation, we have;

Acceleration = (3 - 1)/4

Acceleration = 2/4

Acceleration = 0.5 m/s²

Answer: 10.526m/s

Explanation:

The speed of the toy car would be calculated as the distance travelled by the toy card divided by the time taken. This will be:

= Distance travelled / Time taken

= 60/5.7

= 10.526m/s

The speed of the toy car is 10.526 meters per second.

Answer:

The answer is A

Explanation: i took k12

Answer:

17.56 N

Explanation:

Given that,

Mass of a crate, m = 5 kg

It is on a 21.0° hill

We need to find the y component of the weight.

y component = mgsinθ

Put all the values,

y-component = 5×9.8×sin(21)

= 49×sin(21)

= 17.56 N

So, the y-component of the weight is 17.56 N.

Answer:

-45.745

Explanation:

it is negative because it is downwards.

Answer:

Gamma rays

Explanation:

Answer:

I believe you are correct but we just started this unit

Explanation:

Answer:

Displacement

Explanation:

Displacement is a term used to represent change in position.

Answer:

A. Serbia and service

Explanation:

A guide word is a word written on top of a page to indicate the first or last word entry on that page. For example in a dictionary, they indicate the alphabetical first and last words on the page.

In this example; the word ' serpent ' note the first three letters to guide you in the words that are on that page;

In this case : Serbia  and Service.