I think your answer is b.
A roller coaster of mass 2000 kg is rolling down a track with an
instantaneous speed of 10 m/s. The roller coaster has a force of
unknown magnitude act on it, so now it is traveling at only 6
m/s. What was the work done on it?
Kinetic energy = (1/2) (mass) (speed)²
The coaster's original kinetic energy was
KE = (1/2) (2,000 kg) (10 m/s)²
KE = (1,000 kg) (100 m²/s²)
KE = 100,000 kg-m²/s²
old KE = 100,000 joules
After something slowed it down, its new kinetic energy is
KE = (1/2) (2,000 kg) (6 m/s)²
KE = (1,000 kg) (36 m²/s²)
KE = 36,000 kg-m²/s²
new KE = 36,000 joules
The coaster lost (100,000 - 36,000) = 64,000 joules of KE.
Energy is conserved. It can't evaporate, disappear, or be destroyed.
That 64,000 joules had to go somewhere.
Someone or something had to do 64,000 joules of work on it in order to slow it down.
The work done by the external force on the roller coaster is 64000 J.
How do you calculate the work done on the roller coaster?Given that the mass of The roller coaster is 2000 kg and its velocity is 10 m/s. The kinetic energy of the roller coaster is given below.
[tex]KE = \dfrac {1}{2}mv^2[/tex]
[tex]KE = \dfrac {1}{2}\times 2000\times (10)^2[/tex]
[tex]KE = 100000 \;\rm J[/tex]
Since the roller coaster has a force of unknown magnitude which decreases its speed to 6 m/s. For this decreased speed, the kinetic energy is given as below.
[tex]KE'= \dfrac {1}{2}mv'^2[/tex]
[tex]KE'= \dfrac {1}{2}\times 2000\times 6^2[/tex]
[tex]KE' = 36000\;\rm J[/tex]
The work done on the roller coaster is calculated by the change in the kinetic energy for both speeds.
Work Done = KE - KE'
Work = 100000 - 36000
Work = 64000 J
Hence we can conclude that the work done by the external force on the roller coaster is 64000 J.
To know more about the work, follow the link given below.
https://brainly.com/question/3902440.
If a golf ball is dropped from the thirteenth floor of a building, ignoring air resistance, after falling for 7.00 seconds the speed of the ball will be?
Explanation:
We know that
V = U + at
Here, u is 0 and a is 9.8 which is acceleration due to gravity.
Thus,
V = 9.8 *7
V = 68.6 m/s
Can you hellp me please
Answer:
i think the answer is B but im not sure
Answer:
B
Explanation:
when carbon and oxygen combine chemically, what is true about the mass of the product
Answer: Equal to the mass of the carbon plus the mass of the oxygen
Explanation:
Help me which one dose it go ?:)
Answer:
3. sportsmanship
4. neither A nor B
WILL MARK BRAINLIEST not like anyone answers these.. but i need the RIGHTT ANSWERR people say its A or its D idkk???? u guys confuse me but hereee
The microwave oven was invented in 1945 when some experiments with radar equipment failed and melted some nearby chocolate instead. The scientists realized there were other applications for this energy source. What is this an example of?
A) Creative thinking
B) Scientific method
C) Scientific law
D) Artistic ability
Answer:
B)
Explanation:
Scientific method- a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
in this, the scientist had to test their theories to find a solution to their problem.
A car traveling initially at 7.35 m/s acceler-
ates at the rate of 0.824 m/s² for 2.09 s.
What is its velocity at the end of the accel-
eration?
Answer in units of m/s.
Answer:
[tex]v_f=9,07~m/s[/tex]
Explanation:
Constant Acceleration Motion
It's a type of motion in which the velocity of an object changes uniformly in time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:
[tex]v_f=v_o+at[/tex]
The car initially travels at vo=7.35 m/s and accelerates at a rate of [tex]a=0.824~m/s^2[/tex] during t=2.09 s.
The final velocity is:
[tex]v_f=7.35+0.824*2.09[/tex]
[tex]\mathbf{v_f=9,07~m/s}[/tex]
Any Answer Would Be Appreciated
A thermometer is removed from a beaker of boiling water and placed in a beaker of room temperature water. The thermometer takes 15 seconds to reach a reading of 25°C. The same thermometer is returned to the boiling water for several minutes. It is then placed under a tap of running water at room temperature.The thermometer takes only 10 seconds to reach a reading of 25°C.
What conclusion could you make about conduction and convection based on these observations?
Your answer:
Conduction is a more efficient method of heat transfer.
Convection is a more efficient method of heat transfer.
No valid conclusion is suggested by these observations.
Conduction and convection are equally efficient methods of heat transfer.
Answer:
last one.Condution and convection are equzlly efficentmethods of heat transfer.
Explanation:
Answer: B convection is a more efficient method of heat transfer
Explanation:
hi im learning about zodiac sign can u share urs and what are some things u like to do im a aquarius i play vollyball and sing tysm≅
Answer:
Im a capricorn ! UwU
Explanation:
And well I like to watch my shows
draw / do art
Listen to music
spend time with people I care about
And secretly sing ;>
Hope I could help . :3
Hope u have a amazing rest of your day / night ! <3
Sleepy~
How does the period affects the centripetal force?
What is the kinetic energy of a 72.2kg cheetah moving at a velocity of 25.9m/s?
Answer:
K = 24222.94 J
Explanation:
Given that,
Mass of a cheetah, m = 72.2 kg
Velocity of cheetah, v = 25.9 m/s
We need to find the kinetic energy of the cheetah. Due to the motion of an object, it will have kinetic energy which is given by :
[tex]K=\dfrac{1}{2}mv^2\\\\=\dfrac{1}{2}\times 72.22\times (25.9)^2\\\\=24222.94\ J[/tex]
So, the kinetic energy of the cheetah is 24222.94 J.
What is the difference between zone coverage and man coverage, and how can the offense team read those coverages?
Answer:
zone coverage is about sensing what the offense is attempting to accomplish against the defense. Each defensive player reacts when the ball is in the air, whereas in man-to-man coverage, he simply plays the receiver.
Explanation:
Which of the following is a device that uses a wedge?
Check all that apply.
A. doorknob
B. axe
C. knife
D. baseball bat
Answer:
Axe and a knife
the horizontal distance that each thrown object covers increases as
its initial speed...
A:increases
B:decrease
C: stay the same
Answer:
A
Explanation:
A train of mass 5.6 × 10^5kg is at rest in a station.at time t=0s, a resultant force acts on the train and it starts to accelerate foward. The initial acceleration of the train is 0.75m/s. Calculate the resultant force that acts on train this time.
Answer:
420000N
Explanation:
Given parameters:
Mass of the train = 5.6 x 10⁵kg
Acceleration = 0.75m/s²
Unknown:
Resultant force = ?
Solution:
According to newton's second law, force is the product of mass and acceleration;
Force = mass x acceleration
Resultant force that acts on the train is given below;
Force = 5.6 x 10⁵kg x 0.75m/s² = 420000N
In amplitude modulation, which wave property remains constant?
Which statement summarizes the difference between mass and weight?
Mass is the downward pull on an object due to gravity, and weight is the amount of matter in an object.
Mass is the amount of matter in an object, and weight is the downward pull on an object due to gravity.
Mass is measured in newtons, and weight is measured in pounds.
Mass is measured in pounds, and weight is measured in newtons.
Answer:
its B ; mass is the amount of matter in an object, and weight is the downward pull on an object due to gravity.
Explanation:
I just took the test on edge 2020
When the wedges are removed, the cars will move. Predict which direction they will move and when they will stop(help due by tonight)
Answer:
backwards. they will stop.
Explanation:
they will stop at a point because of the friction and that it couldn't move for ever
A Chevy Camaro drives straight off the top level off a parking garage at 9 m/s. If the car landed 81 meters away from the base of the parking garage, how high (height) was the top level? 196.9 meters 296.9 meters 396.9 meters 496.9 meters
Answer:
The correct option is c: 396.9 meters.
Explanation:
First, we need to find the time at which the car landed:
[tex] v = \frac{x}{t} [/tex]
[tex] t = \frac{x}{v} = \frac{81 m}{9 m/s} = 9 s [/tex]
Now, we can find the height of the top-level:
[tex] y_{f} = y_{0} + v_{0_{y}}t - \frac{1}{2}gt^{2} [/tex]
Since the car has only a velocity in the horizontal direction, we have:
[tex] 0 = y_{0} + 0*t - \frac{1}{2}gt^{2} [/tex]
[tex] y_{f} = \frac{1}{2}gt^{2} = \frac{1}{2}9.81 m/s^{2}*(9 s)^{2} = 397 m [/tex]
Therefore, the correct option is c: 396.9 meters.
I hope it helps you!
What is the focal length of a lens
Answer:
The focal length of a lens is the distance between the lens and the image sensor when the subject is in focus, usually stated in millimeters.
this is refering to a camera lens, not glasses and what not, glasses do not have a focus length, only equipment that has the ability to focus
Explanation:
May I have brainliest please? :)
Helium is an inert gas used in lighter-than-air crafts like blimps because
it is nonflammable. It is formed deep underground over millions of
years as a by-product of the formation of natural gas. Almost all of the
world's helium is found in deep deposits of natural gas within 250 miles
of Amarillo, Texas. Helium can be considered what type of natural
resource? SC.G.2.3.1
A. a fossil fuel
B. a renewable resource
C. a part of the carbon cycle
D. a nonrenewable resource
Answer:
D. a nonrenewable resource
Explanation:
From the description given, helium is a non-renewable resource.
A non-renewable resource is one in which cannot be replenished by natural processes as they consumed. They get depleted as they are removed from nature. Helium formation cannot match its consumption if exploited.A 120-kg roller coaster cart is being tested on a new track, and a crash-test dummy is loaded into it. The roller coaster starts from rest at point A which is 25 m above point B. In your own words, what physics ideas would you be able to use to predict how fast the cart is moving at point B? What calculations would you use, what things would you be measuring, and what physics principles or laws would you use to make this calculation
Answer:
vb = 22.13 m/s
So, the only thing that was measured here was the height of point A relative to point B. And the Law of Conservation of Energy was used.
Explanation:
In order to find the speed of roller coaster at Point B, we will use the law of conservation of Energy. In this situation, the law of conservation of energy states that:
K.E at A + P.E at A = K.E at B + P.E at B
(1/2)mvₐ² + mghₐ = (1/2)m(vb)² + mg(hb)
(1/2)vₙ² + ghₐ = (1/2)(vb)² + g(hb)
where,
vₙ = velocity of roller coaster at point a = 0 m/s
hₙ = height of roller coaster at point a = 25 m
g = 9.8 m/s²
vb = velocity of roller coaster at point B = ?
hb = Height of Point B = 0 m (since, point is the reference point)
Therefore,
(1/2)(0 m/s)² + (9.8 m/s²)(25 m) = (1/2)(vb)² + (9.8 m/s²)(0 m)
245 m²/s² * 2 = vb²
vb = √(490 m²/s²)
vb = 22.13 m/s
So, the only thing that was measured here was the height of point A relative to point B. And the Law of Conservation of Energy was used.
Which formula equation shows a reversible reaction?
Answer:
If this is your question... the answer is C.
Explanation:
For edge:)
Answer:
C on edge2021
Object X travels across a horizontal surface and collides with object Y. The velocity as a function of time for object X and object Y before, during, and after the
collision is shown in the graph. Both objects have a mass of 2 kg. Which of the following correctly describes the momentum p of the system and the kinetic
energy K of the system?
Answer:
The correct option is;
(B) [tex]\underset{P}{\rightarrow}[/tex] is conserved, K Not conserved
Explanation:
From the diagram related to the question and from the question, we have;
m₁ = m₂ = 2 kg
v₁ = 4 m/s, v₂ = -2 m/s, v₃ = 1 m/s, therefore, we have;
The total initial momentum of the system = m₁ × v₁ + m₂ × v₂
m₁ (v₁ + v₂) = 2×(4 - 2) = 4 kg·m/s
The total final momentum of the system = m₁ × v₃ + m₂ × v₃ = 2 ×1 +2 ×1 = 4 kg·m/s
Given that the total initial momentum = The total final momentum, we have that the momentum, p, is conserved
The kinetic energy of the system before collision = 1/2×m₁×v₁² + 1/2×m₂×v₂²
∴ The kinetic energy of the system before collision = 1/2*2*(4)² + 1/2*2*(-2)² = 20 J
∴ The kinetic energy of the system after collision = 1/2×m₁×v₃² + 1/2×m₂×v₃²
1/2*2*(1)² + 1/2*2*(1)² = 2 J
The kinetic energy of the system before collision ≠ The kinetic energy of the system after collision
Therefore, the kinetic energy of the system is not conserved.
If the velocities of object X and object Y after collision is the same (inelastic collision), then only momentum is conserved but if the velocities of both objects after collision are different (elastic collision), then both momentum and kinetic energy are conserved.
According to principle of conservation of linear momentum, the total momentum before and after collision is conserved.
For inelastic collision, only momentum is conserved while kinetic energy is not conserved.
[tex]m_1u_1 \ + \ m_2u_2 = v(m_1 + m_2)[/tex]
[tex]\frac{1}{2} m_1u_1^2 \ + \frac{1}{2} m_2u_2^2 = \frac{1}{2}v^2(m_1+m_2)[/tex]
For elastic collision, both momentum and kinetic energy are conserved;
[tex]m_1u_1 \ + \ m_2u_2 =m_1v_1 \ + \ m_2v_2[/tex]
[tex]\frac{1}{2} m_1u_1^2 \ + \frac{1}{2} m_2u_2^2 = \frac{1}{2}m_1v_1^2 \ +\ \frac{1}{2}m_2v_2^2[/tex]
Thus, we can conclude that, if the velocities of object X and object Y after collision is the same (inelastic collision), then only momentum is conserved but if the velocities of both objects after collision are different (elastic collision), then both momentum and kinetic energy are conserved.
Learn more here:https://brainly.com/question/24424291
How are a concave lens and a convex lens alike? How are they different?
ANSWER
A convex lens acts a lot like a concave mirror. ... A concave lens acts a lot like a convex mirror. Both diverge parallel rays away from a focal point, have negative focal lengths, and form only virtual, smaller images.
which type of bond will sulfer (S) and nitrogen (N) form?
a. metallic bond
b. covalent bond
c. iconic bond
Answer:
In ionic compounds, electrons are transferred between atoms of different elements ... For example, two hydrogen atoms bond covalently to form an H2 molecule; each ... is released when one mole of H2 molecules forms from two moles of H atoms: ... atom in each pair is more electronegative: (a) N or P. (b) N or Ge. (c) S or F.
Explanation:
A politician running for office tells a crowd at a rally that the only way to keep the food chain safe is to stop allowing the growth of genetically-modified crops, or GMOs. Should the politician's statement be considered a scientific fact?
A.
Yes. Public speakers are known to be experts in every subject.
B.
No. He presented no scientific data to support his claim.
C.
No. Only scientists can talk about scientific facts.
D.
Yes. He is probably friends with scientists who work with GMOs.
Answer:
B. No. He presented no scientific data to support his claim.
You are skateboarding in your friend's driveway. You hit a rock and your
skateboard stops, but you go flying forward and hit the ground because of
Answer:
the rock hit the board you go flying because you board stops but you have energy still going so there for you go flying
Explanation:
Answer: You are correct the reasoning is inertia.
Explain: Inertia is the ability to resist change in movement. But that is irrelevant to this question. Newtons first law, “An object in motion stayes in motion unless stopped by an outside force. This case, the outside force is the ground.
A basketball is resting on the ground.
Which claim about the forces acting on the basketball
must be true?
Answer:
b
Explanation:
there is no net force on the basketball
high school and collage students answers only.
Are all compounds molecules? Why or why not?