If a car accelerates from rest at a constant 4 m/s
, how long will it take for the car to reach a
velocity of 28 m/s?​

Answer: 1.79 kW

Explanation:

Given

The temperature of the refrigerator is [tex]T_L=2^{\circ}C\approx 275\ K[/tex]

The temperature of the kitchen is [tex]T_H=22^{\circ}C[/tex]

COP of the refrigerator is

[tex]COP=\dfrac{T_L}{T_H-T_L}=\dfrac{\text{Desired effect}}{\text{Power}}\\\\\Rightarrow COP=\dfrac{275}{22-2}=\dfrac{89}{P}\\\\\Rightarrow P=\dfrac{20}{275}\times 89=6.47\ MJ/h\ \text{or}\ 1.79\ kW[/tex]

Answer:

V = 19.8 m/s

Explanation:

Given the following data:

Initial velocity = 10m/s

Time, t = 1 secs

We know that acceleration due to gravity is equal to 9.8m/s

To find the final velocity, we would use the first equation of motion;

[tex] V = U + at[/tex]

Where;

V is the final velocity.

U is the initial velocity.

a is the acceleration.

t is the time measured in seconds.

Substituting into the formula, we have;

V = 10 + 9.8*1

V = 10 + 9.8

V = 19.8 m/s

Answer:

Description.

Explanation:

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, displacement, position, etc.

A reference point refers to a location or physical object from which the motion (movement) of another physical object or body can be determined.

For example, a point on a map is considered to be a reference point because it represents the starting point of an object or person in motion.

Hence, if the reference point changes, the description of position changes, but the actual position does not change.

D

Explanation:

The are the same but difference

Answer:

Pyrometer, device for measuring relatively high temperatures, such as are encountered in furnaces. Most pyrometers work by measuring radiation from the body whose temperature is to be measured. Radiation devices have the advantage of not having to touch the material being measured.

Explanation:

Answer:

16 Watts

Explanation:

P = VI, where V is the voltage and I is the current (of the lightbulb)

V = 8 volts, I = 2 amps

P = 8 * 2 = 16 Watts

Answer:

Force

Explanation:

The image of the uniform beam is missing, so i have attached it.

Answer:

Option D: 90N acting downwards, 20cm to the left of the midpoint

Explanation:

Taking moments about the pivot, for the beam to be balanced, the moments to the left of the pivot must be equal to the moments to the right of the pivot.

Thus, it also means that; anti clockwise moment = clockwise moment.

Now, from the image, the moment of the left force about the pivot is an anti clockwise moment = 60 × 30 = 1800 N.cm

Now, for the beam to be rebalanced, we need a clockwise moment to the right of the pivot that is equal to 1800 N.cm.

Thus, the clockwise moment would have to be gotten from a downward force to the right of the pivot.

From the options given, the only downward force to the right of the pivot that produces a moment equal to 1800 N.cm is;

Option D: 90N acting downwards, 20cm to the left of the midpoint

Answer:

6.32m/s

Explanation:

note:Now these calculations are based in the fact that acc. due to gravity is 10m/s²

okay so I'm thinking you think the speed of a body depends on the mass of the body also,umh... well it doesn't at all!

when two bodies of different masses fall from the same height,they fall at the same time( this is just to say)

now enough of the talking let solve....

so the ball was dropped .ie from rest to the ground through a distance of 2m,

the formula for calculating the distance if a body moving in a straight line is given by:

S=ut + ½at² where u is initial velocity, a is acceleration ( of the body or due to gravity, but since its falling freely under the influence of gravity its " we use the acceleration due to gravity ,which is 10m/s²) and t is the time taken to cover the distance.

from our question the ball was dropped from rest thus its u is 0 therefore we use this equation to find the time it took to touch ground (S=½at²)

solving ....

we get t to be 0.632s

to find the speed we substitute t in the equation below:

V=u+at ,but since u=0

V=at =10•0.632=6.32m/s

therefore the speed the body uses to strike the ground is 6.32m/s

Answer:

Time = 2758.62 seconds

Explanation:

Given the following data;

Speed = 290 m/s

Distance = 800 km to meters = 800 * 1000 = 800000

To find the time;

Time = distance/speed

Time = 800000/290

Time = 2758.62 seconds

Therefore, it will take the pilot 2758.62 seconds to reach the airport.

Answer:

w=120rpm        

Considering  it  a  disc

L=Iw

=220×(412)×120×602π

=31.415kgm/s

The angular velocity of wheel should be considered as the 31.415kgm/s  when the mass of wheel is 500 and the diameter is 500 revolutions per minute.  

Since  

So here

We know that

w = 120rpm        

And,

L = Iw

So,

= 220×(412)×120×602π

= 31.415kgm/s

hence, The angular velocity of wheel should be considered as the 31.415kgm/s.

Learn more about velocity here: https://brainly.com/question/17802937

Answer:

That guy is right i got a 100 as my score :)

Explanation:

Answer:

c. convection currents in the asthenosphere

Explanation:

Answer:

A

Explanation:

Bauxite is the primary mineral from which aluminum is produced. The ore must first be cleaned before the metal can be electrolytically reduced out of it. Thus, option A is correct.

Bauxite normally has a Mohs hardness of 1 to 3 and is a soft substance. Its color ranges from white to gray to reddish-brown and has a pisolitic structure. It also has an earthy gloss and a specific gravity of 2.0 to 2.5. These characteristics help distinguish bauxite, although they have no bearing on its worth or potential uses.

Typically, aluminum is manufactured in regions with relatively low electricity costs. An abrasive substance is bauxite.

Therefore,  Bauxite is crushed to a fine powder and then fused at a very high temperature to form spherical beads, creating sintered bauxite, which is frequently used as a sand-blasting abrasive.

Learn more about Bauxite here:

https://brainly.com/question/4372634

#SPJ2

The object's velocity is positive and decreasing.

Its acceleration is negative.

Answer:

Mass, M = 4 kilograms.

Explanation:

Given the following data;

Kinetic energy = 50 J

Velocity = 5 m/s

To find the mass of the object;

Kinetic energy can be defined as an energy possessed by an object or body due to its motion.

Mathematically, kinetic energy is given by the formula;

[tex] K.E = \frac{1}{2}MV^{2}[/tex]

Where;

K.E represents kinetic energy measured in Joules.

M represents mass measured in kilograms.

V represents velocity measured in metres per seconds square.

Making mass the subject formula;

[tex] M = \frac{2K.E}{V^{2}}[/tex]

Substituting into the equation, we have;

[tex] M = \frac{2*50}{5^{2}}[/tex]

[tex] M = \frac{100}{25}[/tex]

Mass, M = 4 kg

Answer:

C.) The sperm cells swim to the egg cells through their watery surroundings.

Una reacción química, también llamada cambio químico o fenómeno químico, es todo proceso termodinámico en el cual dos o más especies químicas o sustancias (llamadas reactantes o reactivos), se transforman, cambiando su estructura molecular y sus enlaces, en otras sustancias llamadas productos.

Answer: A chemical reaction, also called chemical change or chemical phenomenon, is any thermodynamic process in which two or more chemical species or substances (called reactants or reactants), are transformed, changing their molecular structure and their bonds, into other substances called products.

Explanation:

Answer:

a=2.4m/s^2

Explanation:

Use V=vi+at

So, 13=25+a5

13-25=a5

[tex]\frac{-12}{5}[/tex]=a

a=2.4m/s^2

Answer:

Jsdiwkwdmxxj we

Explanation:

hcndjnjwidjxnwnjwi

Answer:

2100 N

Explanation:

From the question,

Using the formula

F₁d₁ = F₂d₂..................... Equation 1

Where F₁ = Weight of the Boulder, d₁ = distance moved by the Boulder, F₂ = Force applied on the lever, d₂ = distance moved by the lever.

make F₁ the subject of the equation

F₁ = F₂d₂/d₁.................... Equation 2

Given: F₂ = 350 N, d₁ = 0.25 m, d₂ = 1.5 m

Substitute these values into equation 2

F₁ = 350(1.5)/0.25

F₁ = 2100 N

Answer:

9.59 turns

Explanation:

A test tube looks like cylinder, we can say it has a cross section of circle- like. Then the circumference of the test tube can be determined,Then use it to divide length of the string which answered the question.

Circumference of the tube=( π d)

Where d= diameter

π= 3.142

If we substitute the values, we have

= (3× 3.142)= 9.42cm

length of the string= 90.42cm

Circumference of the tube= 9.42cm

Number of turns around the test tube=

=( length of the string) /Circumference of the tube

=(90.42 ÷ 9.42)

= 9.59cm

Answer:

3 amps

Explanation:

V = IR

I = [tex]\frac{V}{R}[/tex]

I =[tex]\frac{3}{1}[/tex]

I = 3 amps

Answer:

A

Explanation:

Even if the refrigerator did not move he still used energy to try to push it it's just his energy wasnt stronger than the refrigerator's energy

Solution :

It is given that JeLysa Hanson went for a medical examination complaining shortness of breath and tightness in her chest. After the medical examination, she was diagnosed of a musculoskeletal pain that was due to the overexertion while practicing her new hobby of boxing.

Therefore the codes of her examinations are :

ICD Code :

[tex]$R06.02$[/tex] = shortness of breath

[tex]$R07.89$[/tex] = chest pain or chest tightness

[tex]$M79.1$[/tex] = musculoskeletal pain

[tex]$X50.3XXS$[/tex] = overexertion due to the repetitive body movement