Answer:
9 km/h
Explanation:
Speed can be found using the following formula.
s=d/t
where d is distance and t is time.
The car traveled 45 kilometers in 5 hours.
d=45 km
t=5 h
Substitute these values into the formula
s=45 km/5 h
Divide 45 by 5
s=9 km/h
The average speed of the car is 9 kilometers per hour.
A force of 5N compresses a spring by 4cm. Find the force constant of the spring.
Answer:
k = 1,250 N/m
Explanation:
Use the formula F=kx, with F=5N and x=0.04m
Then the spring constant (k) is 5/0.04
If the total momentum of a system of an old woman pushing a shopping cart is 450 kg×m/s, both with a velocity of 3 m/s, and the woman has a mass of 50 kg, what is the mass of the cart?
Answer:
100kg
Explanation:
Momentum is defined as the product of mass times velocity:
[tex]p=mv[/tex]
The total momentum M must be equal to the sum of momentums of the system components, in this case the momentum of the lady plus the momentum of the cart:
[tex]M=m_{woman}v_{woman}+m_{cart}v_{cart}[/tex]
since both the woman and the shopping cart have the same velocity:
[tex]v_{woman}=v_{cart}=v[/tex]
the equation becomes:
[tex]M=m_{woman}v+m_{cart}v\\M=v(m_{woman}+m_{cart})[/tex]
and since we need the mass of the cart we solve for [tex]m{cart}[/tex]:
[tex]m_{woman}+m_{cart}=\frac{M}{v} \\\\m_{cart}=\frac{M}{v} -m_{woman}[/tex]
the values given by the problem are the following:
total momentum: [tex]M=450kgm/s[/tex]
mass of the woman: [tex]m_{woman}=50kg[/tex]
velocity: [tex]v=3m/s[/tex]
we substitute all of them in the equation to find the mass of the shopping cart:
[tex]m_{cart}=\frac{450kgm/s}{3m/s} -50kg\\\\m_{cart}=150kg-50kg\\\\m_{cart}=100kg[/tex]
the mass of the cart is 100kg.
In any case, resistance of a material is a measure of the quantity of
present in the materials.
Answer:
free electrons
Explanation:
Answer:
free electrons
Explanation:
A car weighing 1600 kg is accelerated to 30m/s from start in 20s. Calculate the
acceleration of the car and the magnitude of the force applied.
Answer:
Acceleration = 1.5m/s²Force applied = 2,400NExplanation:
Force is defined as the product of mass of an object and its acceleration.
Force = mass * acceleration and acceleration = velocity/time
Force = mass*(velocity/time)
Given Mass of the car = 1600kg, velocity = 30m/s and time taken = 20secs
Substituting this values in the formula will give;
Force = 1600 * 30/20
Force = 1600 * 1.5
Force = 2,400N
Magnitude of the force applied = 2,400N
Since acceleration = velocity/time
Acceleration = 30/20
Acceleration = 1.5m/s²
Acceleration of the car is 1.5m/s²
A running man cannot stop as soon as he wants to stop. Explain why ?
Plz reply fast
Answer:
mass is not eager to be accelerated or in this case slowed down.
Explanation:
In general, Newton's 1st law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
What this means is that a mass is not eager to be accelerated or in this case slowed down. It will require an external force (muscle power) to get the mass of a running man to slow down. It is not instant also, because it takes time to slow down.
EXTRA
Supose the running man would try to stop instantly by purposely running against a brick wall. Even in that case, there is a small amount of time needed ( a fraction of a second perhaps) in which the moving mass of the man is forced to stop moving. That force is usually so huge, that it will injure someone in case of a crash, which might result even in death!
The purpose of an airbag or wearing a helmet, is to extend the time during a crash, FROM 0 to close to zero.
The layer of foam inside a helmet, protects the head in case of a crash, because it takes an amount of time for the head to squash the foam inside the helmet because the mass needs to be stopped ALMOST instantly. That difference between zero seconds and maybe 1 second, is sometimes enough to be able to survive a crash.
What’s the maximum height of the second hill? Use your answer from part E and the formula PE=m•g•h to determine the answer. Assume that g = 9.8m/sec2.
Answer:
111.4 m
Explanation:
PE = m x g x h
349,300 = 320 x 9.8 x h
h = 349300 : 3136
h = 111,384 m
Some parents build their children’s lives around sports and place a high premium on the successes their children achieve in sports. Such parents often enroll their kids in sports programs when they are in preschool and continue to encourage their involvement in sports through high school and beyond. Many of these parents justify their position by equating success on the playing field with success in the real world. They also cite the benefits of sports to support their decisions: improving physical fitness, building lasting friendships, and acquiring life skills, such as persistence and teamwork. In light of this phenomenon, discuss the benefits and drawbacks to parental involvement in their children’s sports lives. When do parents cross the line between healthy encouragement to prepare their children for success and pushing them to succeed at all costs?
Answer:
I think they cross the line when they force sports into their child's life, and take away their choice of what they want to do so they essentially waste their childhood preparing for something that may never happen or they just don't get the opportunity to explore their artistic abilities.
Explanation:
Which of the following choices is a characteristic of the Baroque period?
clear melodies
simplified orchestration
emotional meaning
grandeur
Answer: C
emotional meaning
Explanation:
Baroque style in the Baroque period is an ancient way of variety of arts used to produce European uniqueness in many art works such as magnificence in sculpture, painting, architecture, literature, dance, music and drama.
The characteristic of the Baroque period that helped to achieve all these is the extravagant display of emotions and details orientation.
as the trait is dominant and controlled by a single gene,the mutation must have occurred on both diploid copies. true or false?
Answer:
False
Explanation:
A dominant trait is a trait that is inherited from parents. It is a trait that is obtained from a particular copy or type of a gene that overshadows or overwhelms the effects of another type or copy of that gene. Dominant traits are controlled by a single gene.
Therefore , as the trait is dominant and controlled by a single gene,the mutation must have occurred on both diploid copies is a false statement.
When the crest of one wave passes through the trough of another wave, ____ takes place. A. resonance B. diffraction C. constructive interference D. destructive interference
When the crest of one wave passes through the trough of another wave, destructive interference takes place.
What is the crest of a wavelength?The crest and trough of a wave, respectively, are its highest and lowest surface portions. The wave height is the vertical distance between the peak and trough. The wavelength is the horizontal separation between two consecutive crests or troughs.
When the crest of one wave passes through the trough of another wave, interference takes place.
This interference can be constructive, where the amplitudes of the waves add up, resulting in a larger wave, or destructive, where the amplitudes of the waves cancel out, resulting in a smaller wave or no wave at all.
The type of interference that occurs depends on the relative amplitudes, wavelengths, and phases of the two waves.
Therefore, destructive interference takes place when the crest of one wave passes through the trough of another wave.
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An electric field is = (400 N/C) for x > 0 and = (–400 N/C) for x < 0. A cylinder of length 30 cm and radius 10 cm has its center at the origin and its axis along the x axis such that one end is at x = +15 cm and the other is at x = –15 cm. What is the net outward flux through the entire cylindrical surface?
Answer:
0 Nm²/C
Explanation:
We calculate the total flux Ф = ∫E.dA for -15 < x < 0 and 0 < x < 15
which is the flux through the curved sides + the flux through its ends.
So, Ф₁ = ∫₋₁₅⁰E.dA + ∫₀¹⁵E.dA this is the flux through the curved sides of the cylinder
Ф₁ = ∫₋₁₅⁰EdAcos0 + ∫₀¹⁵EdAcos0 (since the area is parallel to the electric field)
Ф₁ = ∫₋₁₅⁰EdA + ∫₀¹⁵EdA
Ф₁ = E∫₋₁₅⁰dA + E∫₀¹⁵dA
= E∫₋₁₅⁰2πrdx + E∫₀¹⁵2πrdx
= E2πr∫₋₁₅⁰dx + E2πr∫₀¹⁵dx
= E2πr[x]₋₁₅⁰ + E2πr[x]¹⁵₀
= E2πr[0 -(-15)] + E2πr[15 - 0]
= (-400 N/C)2πr[15] + (+400 N/C)2πr[15]
= -800 N/Cπ(0.30 m )[0.15 m] + 800 N/Cπ(0.30 m)[0.15]
= (-36επ + 36επ) Nm²/C = 0
the flux through the ends is
Ф₂ = ∫₋₁₅⁰E.dA + ∫₀¹⁵E.dA
= ∫₋₁₅⁰EdAcos0 + ∫₀¹⁵EdAcos0 (since the area is parallel to the electric field)
= ∫₋₁₅⁰EdA + ∫₀¹⁵EdA
= E∫₋₁₅⁰dA + E∫₀¹⁵dA
= (-400 N/C)πr² + (400 N/C)πr²
= 0
So, the total flux equals Ф = Ф₁ + Ф₂ = 0 + 0 = 0 Nm²/C
which forces causes oppositely charged particles to attract each other?
Answer:
Electromagnetism causes like-charged objects to repel each other and oppositely charged objects to attract each other. The electromagnetic force binds negative electrons to the positive nuclei in atoms and underlies the interactions between atoms.
what is the efficiency of a machine that can carry a load of 100 kg with an effort of 20N when its velicity ratio is 10 ASAP
Answer:
Efficiency of machine=4.9
Explanation:
We are given that
Mass of load=100 kg
Effort=20 N
Velocity ratio=10
We have to find the efficiency of machine.
Load=[tex]mg=100\times 9.8=980 N[/tex]
Efficiency=[tex]\frac{Load}{effort}\times \frac{1}{velocity\;ratio}[/tex]
Using the formula
Efficiency of machine=[tex]\frac{980}{20}\times \frac{1}{10}[/tex]
Efficiency of machine=[tex]\frac{49}{10}[/tex]
Efficiency of machine=4.9
6. A technlclan can be electrocuted when working on HEVs or EVs.
A) O True
B) O False
Answer:
True
Explanation:
It is true that. A technician can be electrocuted when working on HEVs or EVs, therefore the correct answer is option A
What is an electric vehicle (EV)?An EV stands for an electric vehicle. Electric vehicles (EVs) are autos that are powered totally or partially by electricity. Electric cars are extremely cost-effective to run because they have fewer moving parts to maintain and use little to no fossil fuels (petrol or diesel).
When evaluating its environmental impact, every factor must be taken into consideration. Considering that EVs have a minimal overall environmental impact, this suggests that the severity of these production emissions decreases.
Recycling is one strategy for lowering the lifespan emissions of electric vehicles. Again, incorrect assumptions can be refuted by facts.
Thus, That is accurate. The correct response is option A because a technician could electrocute themselves while working on HEVs or EVs.
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