Which statement is true about how early humans met their needs?

Answer:

B

Explanation:

The Lorentz force is the sum of the electric force and magnetic force.

F = qE + qvB

qE represents electric force and qvB represents magnetic force

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:

is there supposed to be a picture?

Explanation:

The correct order of the springs in increasing spring constant is: W, Y, X, Z. The correct option is A.

Spring constant, also known as force constant or stiffness, is a measure of the resistance of a spring to deformation when a force is applied to it. It is defined as the amount of force required to stretch or compress a spring by a given distance.

The formula for the spring constant is:

k = F/x

Where

k = is the spring constant,

F = is the applied force,

x =is the displacement or deformation of the spring.

The unit of spring constant is newtons per meter (N/m) in the SI system of units, or pounds per inch (lb/in) in the Imperial system.

A higher spring constant means that a spring is stiffer and requires more force to be stretched or compressed by a given distance. A lower spring constant means that a spring is more flexible and requires less force to be stretched or compressed by a given distance. The spring constant is an important property of springs, which are used in various applications, such as in suspension systems, mattresses, and mechanical watches.

Here in the Question,

In order to determine the order of increasing spring constant, we need to compare the given springs and see which one requires more force to stretch or compress.

Therefore, The correct order of the springs in increasing spring constant is: W, Y, X, Z. This is because the spring constant increases as we move from W to Z.

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Answer:

A) Cold object will start getting hot

B) Heat exchange will stop as the two object acquire the same temperature.

Explanation:

A) When one hot object and one cold object are kept in contact then the heat is transferred from the hot object to the cold object via different modes of heat transmission. Hence, the cold object starts getting hot

B) The transmission of heat from the hot object to the cold object will stop as the temperature of the two object becomes equal to each other.

Answer:

D. Forces between molecules

Explanation:

Specific heat capacity of water can be defined as the amount of heat a gram of water must lose or absorb in order to change its temperature by a degree Celsius. It is measured in Joules per kilogram per degree Celsius (J/kg°C). Generally, the specific heat capacity of water is 4.182J/kg°C and is the highest among liquids.

Mathematically, the specific heat capacity of a substance is given by the formula;

[tex] c = \frac {Q}{mdt} [/tex]

Where;

Q represents the heat capacity or quantity of heat.

m represents the mass of an object.

c represents the specific heat capacity of water.

dt represents the change in temperature.

Cohesion is a property of water and it typically refers to the attraction between molecules of water which holds them together.

In Science, the property which helps to explain differences in the specific heat capacities of two substances is the forces between molecules.

This ultimately implies that, the more closely bonded the atoms of a substance are, the higher or greater would be the substance's specific heat capacity. Thus, it varies for the various states of matter i.e solid, liquid and gas.

Answer:

v(t)=3t²+3, and a(t)=6t

v(0)=3cm/sec, and a(0)=0cm/sec²

v(1)=6cm/sec, and a(1)=6cm/sec²

Explanation:

Find velocity and acceleration functions ( v(t) and a(t) )

(Relevant background: Let's say f(t) is a function of y with respect to x. Think of the derivative of this function, f'(t) , as representing the rate at which y changes with respect to x)

s(t) is a function of distance with respect to time. Therefore, s'(t) - the derivative of this - represents the rate at which distance changes with time, which is just the definition of velocity. So we can say velocity v(t) = s'(t).

s(t)=t³+3t+3

s'(t)=v(t)=3t²+3

Similarly, if v(t) is a function of speed with respect to time, then v'(t) represents the rate at which speed changes with time, which is acceleration. So we can say that acceleration a(t)=v'(t)=s''(t)

v(t)=3t²+3

v'(t)=a(t)=6t

Find velocity and acceleration at t=0 and t=1

t=0

v(t)=3t²+3

v(0)=3(0²)+3

v(0)=3 cm/sec

a(t)=6t

a(0)=6(0)

a(0)=0 cm/sec²

t=1

v(t)=3t²+3

v(1)=3(1²)+3

v(1)=3+3

v(t)=6 cm/sec

a(t)=6t

a(1)=6(1)

a(1)=6 cm/sec²

The function ​s(t)=−t3+3t+3 gives the distance from a starting point at time t of a particle moving along a line.

v(t)=3t²+3, and a(t)=6t

v(0)=3cm/sec, and a(0)=0cm/sec²

v(1)=6cm/sec, and a(1)=6cm/sec²

Relevant background: Let's say f(t) is a function of y with respect to x. Think of the derivative of this function, f'(t) , as representing the rate at which y changes with respect to x.

s(t) is a function of distance with respect to time. Therefore, s'(t) - the derivative of this - represents the rate at which distance changes with time, which is just the definition of velocity. So we can say velocity v(t) = s'(t).

s(t)=t³+3t+3

s'(t)=v(t)=3t²+3

Similarly, if v(t) is a function of speed with respect to time, then v'(t) represents the rate at which speed changes with time, which is acceleration. So we can say that acceleration a(t)=v'(t)=s''(t)

v(t)=3t²+3

v'(t)=a(t)=6t

Find velocity and acceleration at t=0 and t=1

t=0

v(t)=3t²+3

v(0)=3(0²)+3

v(0)=3 cm/sec

a(t)=6t

a(0)=6(0)

a(0)=0 cm/sec²

t=1

v(t)=3t²+3

v(1)=3(1²)+3

v(1)=3+3

v(t)=6 cm/sec

a(t)=6t

a(1)=6(1)

a(1)=6 cm/sec²

Therefore, The function ​s(t)=−t3+3t+3 gives the distance from a starting point at time t of a particle moving along a line.

v(t)=3t²+3, and a(t)=6t

v(0)=3cm/sec, and a(0)=0cm/sec²

v(1)=6cm/sec, and a(1)=6cm/sec²

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Answer:

the required wavelength is 1.15815 μm

Explanation:

Given the data in the question;

The position of bright fringes [tex]y_m[/tex] on screen in double slit experiment is expressed as follows;

[tex]y_m[/tex] = mλD / d

solving for d, we substitute 1 for m

y₁ = (1)λD / d

d = λD / y₁

given that λ = 580 nm = 5.8 × 10⁻⁷ m,  D = 3.00 m and y₁= y₀ = 4.81 mm = 0.00481 m

so we substitute

d = λD / y₁

d = ( 5.8 × 10⁻⁷ m × 3.00 m ) / 0.00481 m

d = 0.00000174 m² / 0.00481 m

d = 3.6117 × 10⁻⁴ m

Now, position of dark fringe  [tex]y_m[/tex] on screen in double slit experiment is expressed as;

[tex]y_m[/tex] = ( m + 1/2 )λD / d

we substitute 0 for m

y₀ = ( 0 + 1/2 )λD / d

y₀ = λD / 2d

2y₀d = λD

λ =  2y₀d  / D

we substitute

λ =  ( 2(0.00481 m) ( 3.6117 × 10⁻⁴ m) )  / 3.0 m

λ = 1.15815 × 10⁻⁶ m

λ = 1.15815 μm

Therefore, the required wavelength is 1.15815 μm

Answer:

Therefore it is save to carry a 62kg adult

Explanation:

From the question we are told that:

Mass [tex]m=380kg[/tex]

Height of supporting Rock [tex]X=85cm[/tex]

Length of Board[tex]L_r=4.5m[/tex]

Mass of board [tex]M_b=22kg[/tex]

Mass of adult [tex]M_a=62[/tex]  

Generally the moment of balance about wedge part about  is mathematically given by

[tex]N -Q + R = Mg + mg[/tex]

[tex]0.85*N - Mg*2.25 - mg*(2.25 + x) = 0[/tex]

[tex]0.85*N = + Mg*2.25 + mg*(2.25 + x)[/tex]

where

[tex]N+R=4547[/tex]

therefore

[tex]N = 570.70588 + 1608.3529 + 714.823 x[/tex]

if N=0 at fallen person

[tex]x=3.04m[/tex]

Therefore it is save to carry a 62kg adult

Answer:

Weight is a measure of the force of gravity pulling down on an object. It depends on the object's mass and the acceleration due to gravity, which is 9.8 m/s2 on Earth. The formula for calculating weight is F = m × 9.8 m/s2, where F is the object's weight in Newtons (N) and m is the object's mass in kilograms.

Answer:

ummm i dk what your asking

Explanation:

Answer:

The answer to the question is 7200

Answer:

B. Refraction

Explanation:

Jope this helps

Answer:

Equation of motion is x(t) = [tex]-te^{-4t}[/tex] + [tex]\frac{1}{4}[/tex] sin(4t)

Explanation:

P.S - The exact question is -

Given - A mass of 1 slug, when attached to a spring, stretches it 2 feet and then comes to rest in the equilibrium position. Starting at t = 0, an external force equal to  [tex]f(t) = 8 cos(4t)[/tex] is applied to the system.

To find - Find the equation of motion if the surrounding medium offers a damping force that is numerically equal to 8 times the instantaneous velocity.

Proof -

Given that,

Mass = 1 slug

We know that, 1 slug = 32 lb

Now,

Force, f = kx

⇒32 = k(2)

⇒k = 16

Now,

Given that, C = 8 ( 8 times the instantaneous velocity)

Now,

The differential equation of motion is equals to

mx'' + Cx' + kx = 8 cos(4t)

⇒x'' + 8x' + 16x = 8 cos(4t)               ...........(1)

Let the General solution of equation (1) be

x(t) = x(c) + x(p)

Now,

The auxiliary equation is

m² + 8m + 16 = 0

m² + 4m + 4m + 16 = 0

m (m+4) + 4 (m+4) = 0

⇒(m+4)(m+4) = 0

⇒m = -4, -4

So,

The Complimentary equation becomes

x(c) = [tex]Ae^{-4t} + Bte^{-4t}[/tex]                  ...........(2)

Now,

Let the particular solution be

x(p) = C cos(4t) + D sin(4t)

x'(p) = -4C sin(4t) + 4D cos(4t)

x''(p) = -16C cos(4t) - 16D sin(4t)

It also satisfy equation (1)

Equation (1) becomes

-16C cos(4t) - 16D sin(4t) + 8 [ -4C sin(4t) + 4D cos(4t) ] + 16 [ C cos(4t) + D sin(4t) ] = 8 cos(4t)

⇒-16C cos(4t) - 16D sin(4t) - 32C sin(4t) + 32D cos(4t) ] + 16C cos(4t) + 16D sin(4t) ] = 8 cos(4t)

⇒-4C sin(4t) + 4B cos(4t) = cos(4t)

By comparing, we get

4B = 1 , A = 0

⇒ B = [tex]\frac{1}{4}[/tex] , A = 0

So, The particular solution becomes

x(p) =  [tex]\frac{1}{4}[/tex] sin(4t)

Now,

The General solution becomes

x(t) = [tex]Ae^{-4t} + Bte^{-4t}[/tex] + [tex]\frac{1}{4}[/tex] sin(4t)       .......(3)

Now,

Given that, At t = 0, initial velocity is zero and the system starts equilibrium

⇒x(0) = 0, x'(0) = 0

By putting t = 0 in equation (3) , we get

A = 0

Now,

Differentiate equation (3), we get

x'(t) = [tex]-4Ae^{-4t} + Be^{-4t} - 4Bte^{-4t}[/tex] + [tex]\frac{1}{4}[/tex] *4 cos(4t)

Put t = 0, we get

0 = -4A + B + 1

⇒B = -1

∴ we get

The general solution becomes

x(t) = [tex]-te^{-4t}[/tex] + [tex]\frac{1}{4}[/tex] sin(4t)

Equation of motion is x(t) = [tex]-te^{-4t}[/tex] + [tex]\frac{1}{4}[/tex] sin(4t)

Answer:

static and current electricity

Answer:

A. 1.17

B.

the angular momentum is conserved because there is n o external force doing torque on the pivot

Linear momentum is not conserved because this is not an example of elastic collision where the final and initial kinetic energies are the same

Explanation:

A.

1.17 rad/s

B.

the angular momentum is conserved because there is n o external force doing torque on the pivot

Linear momentum is not conserved because this is not an example of elastic collision where the final and initial kinetic energies are the same

Answer:

Weekly cost = K 8,190

Explanation:

Given the following data;

Resistance, R = 30 Ohms

Current, I = 10 Amps

Time, t = 30 hours

Cost = K13

I. To find the power dissipated;

Power = current² * resistance

Power = 10² * 30

Power = 100 * 30

Power = 3000 Watts

II. To find the energy consumption;

Energy = power * time

Energy = 3000 * 30

Energy = 90,000 Watt-hour = 90 KWh (1 Kilowatts is equal to 1000 watts).

III. To find the weekly cost;

Daily cost = Energy consumption * cost

Daily cost = 90 * 13

Daily cost = K 1170

Therefore, weekly cost = 1170 * 7

Weekly cost = K 8,190

Answer:

hi

Explanation:

answer is C

have a nice day

Answer:

The basic properties (parts) of a wave include: frequency, amplitude, wavelength and speed. Frequency is a measure of how many waves pass a point in a certain amount of time.

Answer:

is the amount of matter in this object

Answer:

B. Containing charged regions

Explanation:

The term i.e. intermolecular forces would be used to explain the attraction forces. Here the interaction would be done between molecules etc that acts between the acts & the other types of particles i.e. neighboring like atoms or ions

So in the given case, the option b would be contributed to the molecules that have intermolecular forces

hence, the option b is correct

Answer:

where a picture

Explanation:

a saan Ang picture

Answer:

Assignment: Calculating Speed Investigation

Data Analysis:

Note: Please submit your data table with this assignment.

1. Write your original hypothesis here.

2. Calculate the average time for vehicle 1 from the information in your data table. Show all work.

3. Calculate the average time for vehicle 2 from the information in your data table. Show all work.

4. Calculate the average speed for vehicle 1 from the information in your data table. Show all work, including the formula used.

5. Calculate the average speed for vehicle 2 from the information in your data table. Show all work, including the formula used.

Conclusion:

Think about this information and then write a conclusion based on the data of this experiment. Don’t forget to connect the conclusion to the original hypothesis.

Were you able to support your hypothesis or not? Be sure to base your answer on the data you collected. Consider whether your conclusion is the only explanation for the data you collected or if there could be alternate explanations. Don’t forget to mention any scientific laws or theories you have studied that would apply to this experiment.

Follow-up Questions:

1. If your experiment did not seem to match the expected results, what did you learn from the experience?

2. Instantaneous speed is the rate of motion of an object at a particular moment in time. What change(s) to the experimental procedure would be necessary if you wanted to gather data on instantaneous speed?

and as for the data can you please make your own

Explanation:

Assignment: Calculating Speed Investigation

Data Analysis:

Note: Please submit your data table with this assignment.

1. Write your original hypothesis here.

2. Calculate the average time for vehicle 1 from the information in your data table. Show all work.

3. Calculate the average time for vehicle 2 from the information in your data table. Show all work.

4. Calculate the average speed for vehicle 1 from the information in your data table. Show all work, including the formula used.

5. Calculate the average speed for vehicle 2 from the information in your data table. Show all work, including the formula used.

Conclusion:

Think about this information and then write a conclusion based on the data of this experiment. Don’t forget to connect the conclusion to the original hypothesis.

Were you able to support your hypothesis or not? Be sure to base your answer on the data you collected. Consider whether your conclusion is the only explanation for the data you collected or if there could be alternate explanations. Don’t forget to mention any scientific laws or theories you have studied that would apply to this experiment.

Follow-up Questions:

1. If your experiment did not seem to match the expected results, what did you learn from the experience?

2. Instantaneous speed is the rate of motion of an object at a particular moment in time. What change(s) to the experimental procedure would be necessary if you wanted to gather data on instantaneous speed?

and as for the data can you please make your ownWhich sentence uses a superlative adjective correctly?

Anthony is running more quickly than anyone else on the field.

Shalon is a very talented pianist.

That is the best chocolate cake I have ever tasted.

Ani is the better gymnast of the two.

Which statement best compares and contrasts the purpose of "PROSERPINE" to that of "How Old Man Winter Was Driven Back"?

The Greek myth explains the creation of the earth, while the Iroquois myth also explains why there is evil in the world.

The Greek myth explains the creation of the earth, while the Iroquois myth also explains the creation of the moon.

The Greek myth explains the changing of the seasons as well as the existence of the underworld, while the Iroquois myth also explains the changing of the seasons.

The Greek myth explains the creation of the moon, while the Iroquois myth explains the creation of the sun.

Read the passages:

from "How Old Man Winter Was Driven Back"

"I, too, am powerful, and I am young! I do not fear you. When I touch the earth, it grows soft and warm. Every living thing stirs in its sleep,—birds and bees, flowers and trees, animals and men. When I speak, the sleeping sun awakes. See! Already he begins to send down his arrows. Hasten! that they may not find you, on the trail to the North Sky."

from "How the World Was Made"

Even some of the trees went to sleep. Only the cedar, the pine, the spruce, the holly, and the laurel were awake all seven nights. Therefore they are always green. They are also sacred trees. But to the other trees it was said, “Because you did not stay awake, therefore you shall lose your hair every winter.”

Which best uses textual evidence to compare and contrast these two myths?

Both myths show the change in seasons as a violent battle.

In "How Old Man Winter Was Driven Back," the change in

To answer the two questions, we need to know two important equations involving centripetal movement:

v = ωr (ω represents angular velocity in radians)

a = [tex]\frac{v^{2}}{r}[/tex]

Let's apply the first equation to question a:

v = ωr

v = ((1800*2π) / 60) * 0.26

Wait. 2π? 0.26? 60? Let's break down why these numbers are written differently. In order to use the equation v = ωr, it is important that the units of ω is in radians. Since one revolution is equivalent to 2π radians, we can easily do the conversion from revolutions to radians by multiplying it by 2π. As for 0.26, note that the question asks for the units to be m/s. Since we need meters, we simply convert 26 cm, our radius, into meters. The revolutions is also given in revs/min, and we need to convert it into revs/sec so that we can get our final units correct. As a result, we divide the rate by 60 to convert minutes into seconds.

Back to the equation:

v = ((1800*2π)/60) * 0.26

v = (1800*2(3.14)/60) * 0.26

v = (11304/60) * 0.26

v = 188.4 * 0.26

v = 48.984

v = 49 (m/s)

Now that we know the linear velocity, we can find the centripetal acceleration:

a = [tex]\frac{v^{2}}{r}[/tex]

a = [tex]\frac{49^{2}}{0.26}[/tex]

a = 9234.6 (m/[tex]s^{2}[/tex])

Wow! That's fast!

We now have our answers for a and b:

a. 49 (m/s)

b. 9.2 * [tex]10^{3}[/tex] (m/[tex]s^{2}[/tex])

If you have any questions on how I got to these answers, just ask!

- breezyツ

Answer:

C.

Explanation:

This is what we call a permanent magnet. By the  way, the magnetic phenomena were first observed about 2500 years ago near the ancient city of Magnesia, what is today Manisa, located in western Turkey, when people saw fragments of magnetized iron. So what happens if you cut a magnet in half? Well, a magnet has two ends, the first one is called a north pole or N pole while the  other end is a south pole or S pole, so if you break a bar magnet, each piece  has a north and south pole, no matter the size of each new bar although the smaller the  piece, the weaker its magnetism. This is true because unlike electric charges, you always find magnetic poles  in pairs, that is, ¡they can't be isolated! The option is C. because in the great bar the north pole is to the left while the south pole is to right.

Answer:

a) 5.23599

b) 0.314159

c) 1.8326

Explanation:

Answer:

a. 5.236 rad

b. 0.314 rad

c. 1.833 rad

Explanation:

300° × π/180 = 5.236rad

18° × π/180 = 0.3142rad

105° × π/180 = 1.833rad

Answer:

(iii) A motor bike.

Explanation:

Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.

In physics, Sir Isaac Newton's first law of motion is known as law of inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.

The inertia of an object such as a trailer is greatly dependent or influenced by its mass; the higher quantity of matter in a trailer, the greater will be its tendency to continuously remain at rest. Also, this is applicable to all physical objects.

Hence, a motor bike would have the lowest inertia because it has the least amount of mass among the other physical objects given in this scenario.

Answer:

I think its d

Explanation:

I'm not sure I'm sorry if I'm wrong

Answer:

Probably electromagnetism

Explanation:

When the door is closed, the steel disk on the door is in close proximity to the coil of wire in the doorframe. This creates a magnetic field around the coil, which induces a small current in the coil.

Ampere's law, which says that the magnetic field created by a current-carrying wire is proportional to the current and inversely proportional to the distance from the wire, may be used to describe the magnetic field produced by a long straight wire carrying a current.

When the door is opened, the steel disk moves away from the coil, which causes the magnetic field to weaken. As a result, the current induced in the coil decreases. This change in current is detected by the home security system as a change in the magnetic field and is interpreted as the door being opened.

In other words, the characteristic of the coil that changes when the door is opened is the amount of current induced in it. The decrease in the magnetic field as the steel disk moves away from the coil results in a decrease in the induced current, which signals to the home security system that the door has been opened.

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Answer:

b

Explanation: