A constant net force of 20 N is applied to a 32kg car, causing it to speed up from 4.0 to 9.0 m/s. How long is the force applied
Answer:
8 seconds
Explanation:
From Newton's second law;
Ft = m(v-u)
F = Force applied
t = time taken
v = final velocity
u = initial velocity
20 * t = 32 (9 - 4)
20t = 32 * 5
t = 32 * 5/ 20
t = 8 seconds
what is Focal Point
help me please
Answer:
The point at which rays or waves meet after reflection or refraction, or the point from which diverging rays or waves appear to proceed is called focal point
Circle the letter of each sentence that is true about calculating the
acceleration of a moving object.
A.) If an object is moving without changing direction, then its acceleration is the change in its speed during one unit of time.
B.) If an object's speed changes by the same amount during each unit of
time, then the acceleration of the object at any time is the same.
C.) To determine the acceleration of an object, you must calculate the
change in velocity during only one unit of time.
D.) If an object's acceleration varies, then you can describe only average
acceleration.
Answer: D
Explanation:
I need help with my science.
Answer:
1: 2
2: 5
Explanation:
hope this helps <3
An object is most likely to become electrically charged by gaining or losing which type of particles?
neutral particles
positive particles
negative particles
none of the above
Answer:
negative particles
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such defines the structure of a chemical element.
Generally, these atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
Hence, an object is most likely to become electrically charged by gaining or losing negative particles.
What is the weather like in a temperate grassland? (Select all that apply.)
summers are mild to hot
winters are cold
summers are cool
winters are mild
Calculate the density of mass 150 grams and volume 35 〖cm〗^3
Explanation:
Mass =150g = 0.15kg
Volume= 35cm^3 = 0.35m^3
Density= Mass×Volume
= 0.15kg × 0.35m^3
= 0.05 kg m^3
8. Calculate the impulse of a 14kg rock that starts at rest and falls to a speed of 6m/s?
Answer:
84 kgm/s
Explanation:
mvf - mvi = impulse
(14kg)(6m/s) - (14kg)(0m/s) = 84 kgm/s
Kitty is pushing her shopping trolley along the ground. She applies a constant force to move the trolley 4 m horizontally. If she does 32 J of work, calculate how much force she is applying.
Answer:
the constant force applied by Kitty is 8 N.
Explanation:
Given;
work done by Kitty, W = 32 J
distance moved by Kitty's trolley, d = 4 m
Let the constant force applied by Kitty = F
The work done by Kitty is calculated as follows;
W = F x d
F = W / d
F = 32 / 4
F = 8 N.
Therefore, the constant force applied by Kitty is 8 N.
True or false- it is possible for a given substance to absorb one frequency of light and reflect a different frequency.
Answer:
FALSE
Explanation:
To answer this question we must clarify that for a given approach to exist there must be a transition between two atomic levels of the material.
For the emission, the transition between two determined states must also occur, therefore the radiation emitted is equal to that absorbed.
Consequently the statement is False
Which of the following statements about mechanical energy is NOT true?
O Gravitational potential energy is a type of mechanical energy.
Kinetic energy is a type of mechanical energy.
O Mechanical energy is the energy an object possesses due to its motion or its position.
O A bungee cord is not an example of mechanical energy.
Each planet has several properties for which scientists colleci Uald. Angle of Axis Tilt Planet Orbital Length Speed of Day (km/s) (hours) Mass (kg) 30 24 Earth 23.4° 6.0 x 1024 Saturn 26.7° 11 5.7 x 1026 10 Another characteristic of Saturn is that it has a much thicker atmosphere than Earth. Based on is most responsible for this difference? O A. their different orbital speeds O B. their difference in length of day O C. their different axis angles of tilt O D. their difference in mass Reset Next Question
Answer:
so basically
Explanation:
ty for the free points tho ez ez ez ez jajjajajajajajjajaj ez ez ez free cash dog water
Any element can always be identified by its_____.
Atomic mass
Number of neutrons
Number of protons
Atomic number
Answer:
c
Explanation:
Answer:
Number of protons and atomic number
Explanation:
A semi-truck as mass of 40 000 kg and is traveling at 80.0 km/h, south. What is
it's momentum? *
A. 210,000 kg m/s
B. 880,000 kg m/s
C. 3,200,000 kg m/s
D. 440,000 kg m/s
Visible light includes all of the
Answer:Visible light is a small part of the electromagnetic spectrum. The spectrum covers everything from gamma rays, x-rays, visible light, infrared, microwave and radio waves. Each part of the spectrum, including the different colors of visible light, have different wavelengths (the space between each wave).
Explanation:
a rail car moving at 10m/s collides with and connect to another stationary car. What is their final velocity?
Assume they have the same mass
Answer:
read this it might help some
When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater collision force. When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater momentum change.
Explanation:
explain about ohm's law.
Answer:
Statement:
The electric current passing through a conductor is directly proportional to the potential difference across its ends provided temperature and other physical conditions remain constant.
Explanation:
Current is directly proportional to voltage loss through a resistor. That is, if the current doubles, then so does the voltage. To make a current flow through a resistance there must be a voltage across that resistance. Ohm's Law shows the relationship between the voltage (V), current (I) and resistance (R).
V∝I or I∝V⇒V=IR.
Explanation:
Ohm's law states that the current through a conductor is proportional to the voltage across the conductor. This is true for many materials (including metals) provided the temperature (and other physical factors) remain constant. The constant of proportionality, R,R is the resistance and the unit is the ohm, with symbol \Omega,Ω. The relationship can be written as:
V, equals, I, R.
V=IR
where V,V is the voltage across the conductor and I,I is the current flowing through it. If a component is ohmic (it obeys Ohm's Law), then its resistance must be independent of current and voltage.
When will an object falling toward earth stop accelerating
Answer:
Hope this helps!
Explanation:
As an object falls, it picks up speed. The increase in speed leads to an increase in the amount of air resistance. Eventually, the force of air resistance becomes large enough to balances the force of gravity. At this instant in time, the net force is 0 Newton; the object will stop accelerating. An object falling toward earth stop accelerating when it velocity becomes terminal velocity. Or When weight becomes equal to Drag force acting on the object due to air resistance.
HELP ✋‼️‼️
What happens to the speed of a sound wave as it travels from air into glass?
Water
Diamond
Glass
Air
1,493
12,000
5,640
346
Speed of
sound
(m/s)
O A. It falls to zero.
B. It decreases.
O c. It stays the same.
D. It increases
Answer:D increases
Explanation:
When sound travels from air into glass, speed of a sound wave increases. Hence option D is correct.
What is a wave ?Wave is a disturbance in a medium that carries energy as well as momentum . wave is characterized by amplitude, wavelength and phase. Amplitude is the greatest distance that the particles are vibrating. especially a sound or radio wave, moves up and down.
Amplitude is a measure of loudness of a sound wave. More amplitude means more loud is the sound wave.
Wavelength is the distance between two points on the wave which are in same phase.
Phase is the position of a wave at a point at time t on a waveform.
speed of the sound is greatest in solid and it is medium in liquid and lowest in gaseous state.
In this problem sound wave is going from air to glass, it is actually going from gaseous to solid state, as speed of sound is greatest in the solid, speed of the sound increases to 5.640 m/s.
Hence option D is correct.
To know more about sound, click :
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Identify the TRUE statements about energy.
A; Energy can transform from electrical energy to heat.
B; Energy can be created and destroyed.
C; Higher potential energy can change into higher kinetic energy.
D; Energy changes are 100% efficient.
Answer:
A, C, D
Explanation:
A, C and D are true.
B is false as energy can neither be created nor destroyed.
You want to create a space station that is 50 meters in radius. If you want it to simulate Earth's gravitation, how fast must it go?
Answer:
w = 0.196 rad / s
Explanation:
To generate an acceleration similar to that of the earth, the station's centripetal acceleration must be equal to the acceleration due to gravity.
a_c = v² / r = w² r
a_c = g
we substitute
g = w² r
w² = g / r
w = [tex]\sqrt { \frac{g}{r} }[/tex]
let's calculate
w = √9.8/50
w = 0.196 rad / s
therefore the station must rotate at that angular velocity so that the acceleration in the outer wall is equal to the ratio of gravity
What is the origin of cold, wet air masses?
A. Over water in tropical zones
B. Over land in polar regions
C. Over land in tropical areas
D. Over water in polar regions
Answer:
b
Explanation:
if it's over land and in polar region it's B
Answer:D
Explanation:
trust me
How many calories are produced when 50 ml of water is raised from 22 degrees celsius to 52 degrees celsius?
Help it’s due today
Answer:1500 calorie
Explanation:
Given
volume of water [tex]V=50\ ml[/tex]
Initial temperature [tex]T_i=22^{\circ}C[/tex]
Final temperature [tex]T_f=52^{\circ}C[/tex]
We know,
specific heat of water is [tex]c=1\ calorie/gm-^{\circ}C[/tex]
the density of water is [tex]\rho=1\ gm/ml[/tex]
The heat required to raise the temperature
[tex]\Rightarrow Q=mc\Delta T\\\Rightarrow Q=\rho \cdot V\times c\times \Delta T\\\Rightarrow Q=1\times 50\times 1\times (52-22)\\\Rightarrow Q=1500\ cal.[/tex]
1500 calories is required
Which of the following best describes how the ocean convection cycle impacts different climates?
A by creating different sea levels
B by adding moisture to the atmosphere
C by transferring heat from the tropics to the colder climates
D by transferring plankton and other sea organisms from cold regions to warm regions
I really need help, I’m giving 90 points to whoever answers
Answer:
the answer is c
Explanation:
by transferring heat from the tropics to the colder climates
The statement which best describes how the ocean convection cycle impacts different climates is by transferring heat from the tropics to the colder climates. Thus, the correct option for this question is C.
What is the Ocean convection cycle?The ocean convection cycle may be characterized as a type of methodology through which the mesoscale ocean circulation and large, strong winds mix layers of water at different depths.
During this cycle, when one part of a fluid is heated, the temperature difference causes by transferring heat from the tropics to the colder climates fluid to move in a current or defined direction. As the heated fluid rises, it is replaced by a cooler fluid, which is sometimes referred to as a convection cycle.
Therefore, transferring heat from the tropics to the colder climates is the process that best describes how the ocean convection cycle impacts different climates. Thus, the correct option for this question is C.
To learn more about Ocean convection, refer to the link:
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suppose kinetic energy is 4 joules of a moving object what will happen if we increase the speed twice
(guys pls show me the work out)
Answer:
The kinetic energy is 16 joules.
Explanation:
Kinetic energy (E) is given by:
[tex] E = \frac{1}{2}mv^{2} [/tex]
Where:
m: is the mass
v: is the speed
When the kinetic energy is 4 joules, the speed of the object is:
[tex] v_{1}^{2} = \frac{2E_{1}}{m} = \frac{8}{m} [/tex]
Now, if the speed is increased twice then we have:
[tex] E_{2} = \frac{1}{2}mv_{2}^{2} = \frac{1}{2}m(2v_{1})^{2} = \frac{1}{2}m[4(\frac{8}{m})] = 16 J [/tex]
Therefore, the kinetic energy is 4 times the initial value.
I hope it helps you!
When the north poles of two magnets are kept close , they will __________
attract
rotate
repel
remain unaffected
a book is sitting on a table. jackie is pushing the book with a force of 9 N to the right. if the force of friction is 4 N to the left, what is the net force?
1. 5 N right
2. 4 N left
3. 5 N left
4. 4 N right
Answer:
1
Explanation:
4+5 =9
5n to the right
Body language is (peer counseling)
the way you make words with your hands
the way you make words by nodding your head
the way you speak by blinking your eyes tightly
the way you speak with your entire body
Answer:
the way you speak with your entire body
Explanation:
Body language is the way you speak with your entire body. Therefore, the correct option is option D.
What is body language?Body language refers to a form of communications in which information is expressed or conveyed via bodily behaviors rather than words. Face expressions, body posture, movements, eye movement, touch, and use of space are examples of this type of behavior.
Although the phrase "body language" is typically used in reference to people, it can also be used in reference to animals. Kinesics, another name for the research of body language, is related. Although facial expression is a crucial component of communication, much of it occurs subconsciously. Body language is the way you speak with your entire body.
Therefore, the correct option is option D.
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Explain why white light splits up into the different colours when it goes through a prism
Explanation:
beacuse light is mixture of many different colours,each with different frequency
give two reasons why biomass energy might not be a good alternative Energy source
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as for the production of biomass energy wood is mostly used source and burning of wood for the production of biomass energy can lead to the risk of deforestation in the future and emissions of carbons, pollute the surrounding. Thus this is the reason biomass energy might not be a good alternative energy source.
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