A teacher needed to get a box of old books onto the top shelf of a bookcase in a new
apartment. The box was on the floor at the base of the bookcase. The box had a mass
of 15.0 kg, and it was lifted at a constant speed to the top shelf. A.220 B.22.5 C.0 D.16.5

Answers

Answer 1

Answer:

WHY THE HE!! DO YOU HAVE B00BS AS YOUR

PIC

Explanation:


Related Questions

A pendulum swings back and forth. Is there energy in the system?

Answers

Answer:

yes

Explanation:

A pendulum should be able to contain enough energy to constantly be moving

A baseball on the Moon and an identical baseball on the Earth are thrown vertically upward with the same initial velocity of 12 m/s. The acceleration due to gravity on the Moon is 1/6 that of Earth. What is the maximum height the ball reaches on the moon? What is the maximum height the ball reaches on the earth? What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?

Answers

Answer:

a. 3.68 m b. 0.61 m c. 3.07 m

Explanation:

a. What is the maximum height the ball reaches on the moon?

Using v² = u² - 2g'h where u = initial velocity of baseball = 12 m/s, v =  final velocity of baseball = 0 m/s (since it stops at maximum height), g' = acceleration due to gravity on moon = g/6 where g = acceleration due to gravity on earth = 9.8 m/s², so g' = 9.8 m/s²/6 = 1.63 m/s² and h = maximum height of ball on moon.

So, making h subject of the formula, we have

h = -(v² - u²)/2g'

substituting the values of the variables, we have

h = -((0 m/s)² - (12 m/s)²)/2(1.63 m/s²)

=  -(- 12 m²/s²)/2(1.63 m/s²)

= 6 m²/s²)/(1.63 m/s²)

= 3.68 m

b. What is the maximum height the ball reaches on the earth?

Using the same equation for the maximum height the baseball travels on the moon for that on the earth, the maximum height h' the baseball travels on the earth is given by  

h' = -(v² - u²)/2g where u = initial velocity of baseball = 12 m/s, v =  final velocity of baseball = 0 m/s (since it stops at maximum height),  g = acceleration due to gravity on earth = 9.8 m/s²and h' = maximum height of ball on moon.

substituting the values of the variables, we have

h = -((0 m/s)² - (12 m/s)²)/2(9.8 m/s²)

=  -(- 12 m²/s²)/2(9.8 m/s²)

= 6 m²/s²)/(9.8 m/s²)

= 0.61 m

c. What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?

The difference in the maximum height the ball reaches on the Moon compared to on Earth is d = h - h' = 3.68 m - 0.61 m = 3.07 m

21. A teacher does the following:
i. walks 4 m, south
ii. walks 8 m, east
iii. walks 4 m, north
iv. walks 8 m, west.
The overall displacement of the teacher is
a. Om
b. 6 m
c. 12 m
d. ... Nonsense! It cannot be calculated without knowing time information.

Answers

Answer:

displacement is the change from a starting point. she ends up back where she started so her displacement is zero meters although she traveled 24m in all.

Gravity affects atmospheric pressure true or false

Answers

Answer:

false

Explanation:

A rock is dropped into a canyon that is 0.3 km deep. Determine the time it takes the rock to hit the bottom of the canyon?

Answers

Answer:

rock of mass m is dropped to the ground from a height h. A second rock, with mass 2m, is dropped from the same height. When the second rock strikes the ground, what is its kinetic energy? (a) Twice that of the first rock, (b) four times that of the first rock, (c) same as that of the first rock, (d) half as much as that of the first rock, (e) impossible to determine.

If a  rock is dropped into a canyon that is 0.3 km deep, then the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.

What are the three equations of motion?

There are three equations of motion given by  Newton

v = u + at

S = ut + 1/2 × a × t²

v² - u² = 2 × a × s

Keep in mind that these calculations only apply to uniform acceleration.

As given in the problem, if a rock is dropped into a canyon that is 0.3 km deep.

By using the second equation of motion given by Newton,

S = ut + 1/2at²

300 = 0 + 0.5 × 9.8 × t²

t² = 300 / 4.9

t = 7.82 seconds

Thus,  the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.

To learn more about equations of motion here, refer to the link given below  ;

brainly.com/question/5955789

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water starts to freeze from top whereas wax starts to freeze from bottom?why?​

Answers

Answer:

im pretty sure its because wax has i higher melting point therefore it would cool quicker if the temperature dropped more. water has a lower melting point so it takes longer to freeze i think. i hope this helps

Water and wax freeze from different directions due to the unique properties and behaviors of these substances.

Water:

When water freezes, it undergoes a phase transition from a liquid to a solid state.

Unlike most substances, water exhibits an unusual property known as the "anomalous expansion of water" or "density anomaly." This anomaly is caused by the hydrogen bonding between water molecules.

As the water cools down, its molecules begin to slow down and move closer together. This causes the density of the water to increase. However, as the water reaches around 4 degrees Celsius (39 degrees Fahrenheit), it starts to behave differently.

The hydrogen bonds between water molecules become more organized and stable, causing the water to expand and become less dense.

Wax:

Wax, on the other hand, does not exhibit the same density anomaly as water. When wax undergoes solidification, it follows a different pattern due to its molecular structure and the way its particles arrange themselves.

Wax typically consists of long, nonpolar hydrocarbon chains. As it cools, the wax molecules start to lose kinetic energy, slowing down their movement.

The intermolecular forces between the wax molecules become stronger, causing them to come closer together.

In summary, water freezes from the top due to its density anomaly, with the less dense, expanded water rising and forming a layer of ice on the surface.

Wax, however, freezes from the bottom as its molecules arrange and bond together, gradually solidifying upwards. These differences in freezing behavior are influenced by the distinct properties and molecular structures of water and wax.

Know more about hydrogen bonds:

https://brainly.com/question/30885458

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1) A rock was thrown horizontally from a 500.0 m high cliff. It
strikes the ground 100.0 m from the base of the cliff. At
what speed was it thrown?

Answers

Answer:

twenty two miles per hour

Jessica did an investigation about the states of matter. As part of the investigation, Jessica wanted to change a liquid into a solid. What must she do to bring about this change in state?

place the liquid in a different container
A
B
stir the liquid as quickly and thoroughly as possible
C
remove energy from the liquid so that its particles slow down
D
increase the energy of the liquid so that its particles move faster

Answers

В общем то что я могу когда ккщ на русском бесплатно без вирусов и бактерий к тебе на меня не будет так же как и все равно не будет так как я не могу найти человека с натуры

Answer:

D : Increase the energy of the liquid so that its particles move faster

Explanation:

Sorry the other guy was wrong can i have brailiest please.

Ronald observes a large island off the coast of Indonesia on a map. A few months later, he observes that there are many smaller islands in place of the large one he had seen earlier. Which of these could have caused this change?

Answers

D is the correct answer

Answer:

idgaf

Explanation:

lol

Which element accumulates in the environment due to the use of
fertilizers?
A. oxygen
B. hydrogen
C. nitrogen
D. carbon

Answers

To Find :

Which element accumulates in the environment due to the use of  fertilizers.

Solution :

Most of the fertilizers used in daily practice are nitrogen fertilizers .

When soil became waterlogged, soil organisms take the oxygen they need from nitrates, leaving the nitrogen in a gaseous form which escapes into the air.

Also, nitrogen is very stable and did not participate in most of the reactions.

So, nitrogen is accumulates in the environment .

Therefore, option C. is correct.

A 10 N force and an 18 N force act in the same direction on an object. What is the net force on the object?

Answers

Answer:

28 N

Explanation:

From the question given above, we were told that 10 N force and 18 N force act in the same direction on the object.

The net force acting on the object can be obtained by simply adding both forces together since they both act on the object in the same direction. This is illustrated below:

Force 1 (F₁) = 10 N

Force 2 (F₂) = 18 N

Net force (Fₙ) =?

Fₙ = F₁ + F₂ (since they both act in the same direction)

Fₙ = 10 + 18

Fₙ = 28 N

Therefore, the net force acting on the object is 28 N.

how many cups are in 4 gallons

Answers

Answer:

there are 64 cups

Explanation:

remember this: two cups in a pint, two pints in a quart, two pints in a quart, four quarts in a gallonl2

An object is thrown straight up into the air with an initial speed of 8 m/s, and reaches a greatest height of 15 m before it falls back to the ground. a. What height is the object thrown from? b. How long does it take for the object to hit the ground?

Answers

Answer:

The value is [tex]T_t = 2.5659 \ s[/tex]    

Explanation:

From the we are told that  

         The initial speed of the object is  [tex]u = 8 \ m/s[/tex]

         The greatest height it reached is  [tex]h = 15 \ m[/tex]

Generally from kinematic equation we have that

      [tex]v^2 = u^2 + 2gH[/tex]

At maximum height v  =  0 m/s

So

      [tex]0^2 = 8^2 + 2 * - 9.8 * H[/tex]

=>    [tex]H = 3.27 \ m[/tex]

Here H is the height from the initial height to the maximum height

So the initial height is mathematically represented as  

      [tex]s = h - H[/tex]

=>    [tex]s = 15 - 3.27[/tex]

=>    [tex]s = 11.73 \ m[/tex]

Generally the time taken for the object to reach maximum height is mathematically evaluated using kinematic equation as follows

            [tex]v = u + (-g) t[/tex]

At maximum height v  =  0 m/s

           [tex]0 = 8 - 9.8t[/tex]

=>         [tex]t = 0.8163 \ s[/tex]

Generally the time taken for the object to move from the maximum height to the ground is mathematically using kinematic equation as follows

       [tex]h = ut_1 + \frac{1}{2} gt_1^2[/tex]

Here the initial velocity is  0 m/s given that its the velocity at maximum height

Also  g is positive because we are moving in the direction of gravity  

So

       [tex]15 = 0* t + 4.9 t^2[/tex]

=>      [tex]t_1 = 1.7496[/tex]

Generally the total time taken is mathematically represented as

          [tex]T_t = t + t_1[/tex]

=>        [tex]T_t = 0.8163 + 1.7496[/tex]

=>        [tex]T_t = 2.5659 \ s[/tex]            

 

HELP ASAP

The Target employees are working hard to get the orders out to everyone. The employees need to move packages from the ground level to the top of the loading dock platform. As shown in Figure 1, the employee pushes the package up a ramp (you may assume friction is negligible). In figure 2, the employee lifts the package straight up from ground to the loading dock platform. In which case does the employee do more work on the box and why?

a
Lifting the box straight up, because the incline acts as a simple machine and reduces the force required
b
Lifting the box straight up, because it requires a larger applied force to lift it straight up
c
Pushing the box up the incline, because the force is applied for a longer distance
d
Neither method, because the work is the same in both cases, since using the ramp decreases the force by the same factor that it increases the distance

Answers

Answer:

I believe the answer is B

Help me please :))))))

Answers

Answer:

first one is d second is a

Explanation:

hope this helps luv

Hardin electronic corporation is designing a new cell phone, they need a solid material that will insulate the phone and product their users from electric shock. Which material would best fit the needs of Hardin engineers A. A non-metal B. A metalloid C. A metal D. A semiconductor

Answers

Answer:

A

Explanation:

The material that would best suit Hardin electronic corporation's need would be a non-metal.

Non-metals are naturally occurring substances or materials that lack the properties of metals. In other words, non-metals are poor conductors of heat and electricity, unlike metals.

Solid non-metals are, therefore, used as insulators in the design of materials. Hence, the best material for Hardin electronic corporation to use that will insulate the phone and protect their users from electric shock would be a non-metal.

The correct option is A.

Which of these is an example of electrical energy being converted to mechanical energy?

Group of answer choices
Sunlight used by plants in photosynthesis
Ceiling fan
Lightning striking the ground

Answers

Answer:

Ceiling fan

Explanation:

A ceiling fan is an example of electrical energy being converted to mechanical energy.

The blades of the fan are driven by motor within the system.

Energy in a system is converted from one form to the other. Energy is neither created nor destroyed as we know from the law of conservation of energy. In this regard, the electrical energy from the outlet powers the motor. As the motor inside the fan spins, the blade in turn begins to rotate. The motion of the blade is the expression of mechanical energy.

Which of these is not a method of preventing the corrosion of metals?
A) galvanising
B) painting
C) plating
D) rusting

Answers

Answer:

D

Explanation:

rusting is actually the corrosion of metals so it can't be a way to prevent itself.

A person pours some chlorine bleach into a clothes washer to remove stains from the clothing. What is one chemical property or the bleach?

A. It’s density
B. It’s mass
C. It’s color
D. It’s pH

Answers

One chemical property of the bleach is its pH.

What is pH?

This is referred to as the power of hydrogen and is a measure of how acidic/basic a substance is.

pH is an example of  chemical property because it's associated with a change in its chemical composition. This thereby makes option D the most appropriate choice.

Read more about pH here https://brainly.com/question/4137247

Answer:   It's   pH

Explanation:   I took the test

the weight of a person is 400N. he exerts 400N/m² pressure if he stands with both feet. Find the area of the floor covered by his both feet.

Answers

Answer:

1 m²

Explanation:

The area of the floor covered by his both feet can be found by using the formula

[tex]a = \frac{f}{p} \\ [/tex]

f is the force

p is the pressure

From the question we have

[tex]a = \frac{400}{400} = 1 \\ [/tex]

We have the final answer as

1 m²

Hope this helps you

A car travels 300km in six hour. What is the average speed

Answers

Answer:

50 km/hr

Explanation:

The average speed of the car can be found by using the formula

[tex]s = \frac{d}{t} \\ [/tex]

d is the distance

t is the time taken

From the question we have

[tex]s = \frac{300}{6} = 50 \\ [/tex]

We have the final answer as

50 km/hr

Hope this helps you

Answer:

50mph

Explanation:

Just do[tex]\frac{300}{6}[/tex] (aka 300 divided by 6)

And you'll get 50 as your answer!

Hope this helps! Ty!

CAN SOMEONE HELP ME WITH THIS QUESTION!!

Answers

Answer:

The one you have selected

Explanation:

That is right


If the person's velocity is changing is the person
accelerating

Answers

Answer:

a change in velocity can be a change in magnitude (or speed), but it can also be a change in direction.

A food packet is dropped from a helicopter during a flood-relief operation from a height of 750 meters. Assuming no drag (air friction), what will the velocity of the packet be when it reaches the ground?

Answers

Answer: 121.2 m/s

Explanation:

Here we will use the conservation of energy.

We can write the total energy of an object as:

E = K + U

For this particular case we have:

K = kinetic energy = (m/2)*v^2

U = potential energy = m*g*h

where:

m = mass of the object.

g = gravitational acceleration = 9.8m/s^2

h = height at which the object is dropped, in this case 750m

v = velocity of the object.

Right when the packet is dropped, it's velocity is equal to zero, this means that there is no kinetic energy and only potential energy, then we have:

Ei = Ui = m*9.8m/s^2*750m = m*(7350m^2/s^2)

And when the object is about to hit the ground, h will be almost equal to zero, this will mean that we will have only kinetic energy, and because of the conservation of energy, this final energy must be the same as the initial energy, then we will have

Ei = Ef

m*(7350m^2/s^2) = Ef = Kf

m*(7350m^2/s^2) = (m/2)*v^2

We can divide by m in both sides to get:

(7350m^2/s^2) = (1/2)*v^2

√( 2*(7350m^2/s^2)) = v = 121.2 m/s

Then the velocity of the packet when it reaches the ground is 121.2 m/s

A student wearing a frictionless roller skates on a horizontal is pushed by a friend with a constant force of 55N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 362 J

Answers

Answer:

6.58m

Explanation:

The kinetic energy = Workdone on the roller

Workdone = Force * distance

Given

KE = Workdone = 362J

Force = 55N

Required

Distance

Substitute into the formula;

Workdone = Force * distance

362 = 55d

d = 362/55

d = 6.58m

Hence the student must push at a distance of 6.58m

Which of these games was a racing game?
A.
Centipede
B.
Pole Position
C.
Xevious
D.
Galaxian
E.
Space Invaders

Answers

Answer:

B.

pole position

Identify the type of motion that occurs when a body moves around its own center of mass.

circular
revolution
rotation
resolution

Answers

Answer:

circular

Explanation:

a man walks 30 meters north,then 90 meters east, and then 30 meters south​

Answers

Explanation:

D = 30+90+30

= 150m

.............

what's the question

A soccer player kicks a ball 6.5 meters. How much time is needed for the ball to travel this distance if its velocity is 22 meters per second?

Answers

. . .

. . .

. . .

!

.

Your answer is 0.30 seconds

Form hypothesis: How do you think increasing the resistance in a circuit will affect the current in the wire? (format: if, then, because)

Answers

Answer:it would make it thicker

Explanation:

Answer:

"The equation shows that the current in a circuit is inversely proportional to the resistance of the circuit. An increase in resistance would result in a decrease in current. And the factor by which the resistance increases is the same factor by which the current decreases."

Explanation:

Because it's just like wearing a glove/mitten when getting something out of the oven, because of the insulation from the glove/mitten, it reduces the heat that gets through into your hand, and it protects it. Just like what the "answer" says, it said that the resistance would decrease current.

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