Which of the following is for forbidden based on the second law of thermodynamics?
A) Heat flowing from hot to cold
B) A machine that is 100% efficient
C) Energy being wasted when heat is converted into mechanical energy
D) Heat flowing from hot to cold
Answer: B) A machine that is 100% efficient
Explanation:
The second law of thermodynamics states that a machine will always be less than 100% efficient as heat is never converted completely into mechanical energy. Even an ideal, frictionless engine can't convert anywhere near 100% of its input heat into work.
Second law of thermodynamics states that any natural system tends to disorder. That is, the total entropy of the universe will tend to increase over time. Heat will alwyas from a hotter body to a colder body.
11)
Which is an example of a solution?
A)
air
B)
oxygen
salt
w
nulas
D)
water
Answer:
salt w nulas...........
What is the eccentricity of an ellipse with a foci distance of 50,000,000 km and
a major axis of 100,000,000 km. (Picture not to scale)
Answer:
25,000,000 Km ;)
Explanation:
An 8.0 kg object starts from rest and is pushed with a horizontal 24.N force for 10. s on a surface with negligible friction. Then the applied force is removed and the object then encounters a rough surface and slows to a stop in an additional 10. seconds.
a) What TOTAL distance did the object cover?
The 24 N force applies an acceleration a₁ such that
24 N = (8.0 kg) a₁
a₁ = (24 N) / (8.0 kg)
a₁ = 3.0 m/s²
Starting from rest, the object accelerates at this rate for 10 s, so that it reaches a velocity v of
v = (3.0 m/s²) (10 s)
v = 30 m/s
and in these 10 s, the object travels a distance d₁ of
d₁ = 1/2 (3.0 m/s²) (10 s)²
d₁ = 150 m
When it hits the rough surface, it slows to a stop in 10 s, so that its accleration a₂ during this time is such that
0 = 30 m/s + a₂ (10 s)
a₂ = - (30 m/s) / (10 s)
a₂ = -3.0 m/s²
so that it covers an additional distance d₂ such that
d₂ = 1/2 (-3.0 m/s²) (10 s)²
d₂ = 150 m
So the object travels a total distance of d₁ + d₂ = 300 m.
Alternatively, once we find the accelerations during both 10 s intervals and the velocity after the first 10 s, we get
(30 m/s)² - 0² = 2 (3.0 m/s²) d₁
d₁ = (30 m/s)² / (6.0 m/s²)
d₁ = 150 m
and
0²- (30 m/s)² = 2 (-3.0 m/s²) d₂
d₂ = (30 m/s)² / (6.0 m/s²)
d₂ = 150 m
so that, again, d₁ + d₂ = 300 m.
Answer:
300 m
Explanation:
Displacement in the first 10 seconds:We can find the acceleration of the object by using Newton's 2nd Law: F = ma.
24 N = (8 kg) * aDivide both sides by 8.
a = 3 m/s²We can find the final velocity (v) using the acceleration since a = v/t.
3 m/s² = v/10 sMultiply 10 to both sides.
v = 30 m/sList out the variables we have for the object during its first 10 seconds in motion.
v_f = 30 m/sa = 3 m/s² t = 10 sv_i = 0 m/sWe want to solve for the displacement in the x-direction during the first 10 seconds, so we can use this constant acceleration kinematics equation:
Δx = v_0 t + 1/2at²Plug in known values into the equation.
Δx = (0 m/s)(10 s) + 1/2(3 m/s²)(10 s)²Remove units to make it easier to read.
Δx = (0)(10) + 1/2(3)(10)²0 * 10 cancels out, and we are left with:
Δx = 1/2(3)(10)²Simplify this equation.
Δx = 1.5 * 100Δx = 150 mThe displacement in the x-direction is 150 m during the first 10 seconds of the object's motion.
Displacement in the last 10 seconds:Now we want to solve for the acceleration during the last 10 seconds while the object is slowing down and stopping.
Since the object stops, the final velocity is 0 m/s. We know the final velocity of the first 10 seconds is the initial velocity of the last 10 seconds.
Let's use this constant acceleration equation to solve for a:
v = v_0 + atPlug in known variables:
0 = 30 m/s + a(10 s)Subtract 30 from both sides of the equation.
-30 = 10aDivide both sides of the equation by 10.
a = -3 m/s²List out known variables for the last 10 seconds of the object in motion:
v_f = 0 m/sa = -3 m/s² t = 10 sv_i = 30 m/sLet's use the same equation we used for the first 10 seconds since we have the same known variables:
Δx = v_0 t + 1/2at²Plug in known values:
Δx = (30 m/s)(10 s) + 1/2(-3 m/s²)(10 s)²Remove units to make the equation easier to read.
Δx = (30)(10) + 1/2(-3)(10)²Simplify this equation.
Δx = 300 - 1.5(100) Δx = 300 - 150Δx = 150 mThe displacement in the x-direction for the last 10 seconds is equal to the displacement for the first 10 seconds.
Let's add these together:
150 m + 150 m = 300 mThe total distance the object covered is 300 meters.
Compare venus's rotation to Earth's
Firstly its axis of rotation is inclined at 177.36 degrees (compared to 23.5 degrees on Earth). This means that Venus rotates in a retrograde direction from east to west, making the Sun rise in the west and set in the east. Further to this the rotation is very slow: a sidereal day on Venus lasts 243 Earth days.
You're welcome Have a nice Thursday ✨
A 350 kg car traveling on cruise control requires 127 - N of force to maintain constant speed. How much work must be done to move the car 55 meters down the highway?
Answer:
43-Z
Explanation:
an object starts from rest and travels 100 m in 10 s. what will be the velocity of the object after 10 s
Answer:
10m/s (if the velocity is constant!!)
Explanation:
v=Δx/Δt=100/10=10m/s (if the velocity is constant!!) (i dont know if the letters are right in english sorry)
HELP BRAINLIEST!!! I NEED HELP NOW
Answer:
1 kg at 1 m/s
Explanation:
less weight to propell it forward
Which of these does NOT affect the rate of a chemical reaction?
O duration
O temperature
presence of a catalyst
O concentration
Answer:
Duration
Explanation:
Because duration is not a factor, but it's the outcome or effect or observation from the reaction used to give the rate of reaction
The speed and direction of an object's motion is its?
Answer:
Speed and direction of motion is velocity. ... A change in speed is a change in velocity – so, a change in speed is an example of acceleration!
Measure
Remember that velocity includes the speed and direction of an object. Therefore, a change in velocity can be either a change in how fast something is moving or a change in the direction it is moving.
The speed and direction of an object in motion is called velocity
How do i know what speed and direction is called?Speed is defined the distance traveled with time. Mathematically, it is expressed as:
Speed = distance / time
Direction of an object is simply the path of motion of an object.
Velocity of an object is defined as the displacement traveled with time i.e
Velocity = displacement / time
Displacement of an object is the distance in a specific direction.
Thus, we can say that the velocity of an object is the speed in a specific direction.
With the above information in mind, we can conclude that the speed and direction is called velocity.
Learn more about velocity and speed:
https://brainly.com/question/1435482
#SPJ6
What is the process called when a solid changes to a
liquid?
???20 points?ASAP please
Answer:
melting
Explanation:
Answer:
melting
Explanation:
Melting, change of a solid into a liquid when heat is applied.
Dennis the Menace is shooting a rock with his slingshot with an initial height of 5 feet. The height in feet, of the rock above the ground is given by s(t)=-16t^2+44t+5, where t is time in seconds and t is >= 0. At what time will the rock be 15 ft above the ground?
Answer: 32
The average velocity of the rock would be 32 ft per second.
The rock will be 15ft above the ground 0.25 and 2.5secs after
The height of the rock above the ground is expressed according to the expression [tex]s(t)=-16t^2+44t+5[/tex]
In order to get the time the rock will be 15ft above the ground, we will substitute s(t) = 15 ft into the formula above;
[tex]15= -16t^2+44t+5\\-16t^2+44t = 15 -5\\-16t^2+44t = 10\\-16t^2+44t- 10 = 0\\16t^2-44t+10=0[/tex]
Factorize the expression to get the value of "t"
2(4t−1)(2t−5) = 0
4t - 1 = 0
4t = 1
t = 0.25secs
Similarly 2t - 5 =0
2t = 5
t = 5/2 = 2.5secs
This shows that the rock will be 15ft above the ground 0.25 and 2.5secs after
Learn more on equations here: https://brainly.com/question/15566496
Plz, help me! I will give brainliest
Answer:
Its B.
Explanation:
I don't really know how to explain it but thats the answer.
How much kinetic energy does an 80 kg man have while running at 3 m/s?
Hello!
[tex]\large\boxed{KE = 360 J}[/tex]
Use the equation KE = 1/2mv² to solve for the kinetic energy of the man.
We are given the mass and velocity, so plug these values into the equation:
KE = 1/2(80)(3²)
KE = 1/2(720)
KE = 360 J
An object falls freely from rest through a vertical distance off 44.0m in a time of 3.0s. What value should be quoted for the acceleration of free fall?
Answer:
9.8m\sec
Explanation:
free falling neglecting the air drag so its acceleration will be the acceleration due to gravity
13. Suppose you have an object tied to a rope and are rotating it over your head in uniform circular motion. If you increase the
length of the rope, would you have to apply more or less force to maintain the same speed?
a. More force is required, because the force is inversely proportional to the radius of the circular orbit.
b. More force is required because the force is directly proportional to the radius of the circular orbit.
c. Less force is required because the force is inversely proportional to the radius of the circular orbit.
d. Less force is required because the force is directly proportional to the radius of the circular orbit.
Answer:
The correct option is (c).
Explanation:
When an object tied to a rope and we rotate it, the centripetal force acting on it. This force acts towards the center of the circle. The magnitude of the force is given by :
[tex]F=\dfrac{mv^2}{r}[/tex]
Where,
m is mass, v is speed and r is radius of path
If the length of the rope is increased, it means it will make a large circle i.e. large radius.
As we can see that force is inversely proportional to the radius of circle. It means less force is required because the force is inversely proportional to the radius of the circular orbit. Hence, the correct option is (c).
To move an object at a constant speed after increasing the length of the rope, less force is required because the force is inversely proportional to the radius of the circular orbit. Thus option C is correct.
The force applied to the object moving in a circular motion can be given by:
[tex]\rm Force\;=\;\dfrac{mass\;\times\;(speed)^2}{radius}[/tex]
From the equation, it is evident that force has been inversely proportional to the radius of the circular path. Since the length of the rope is doubled, the radius the circular path has also been doubled.
If we apply the same unit of force, the speed of the motion will increase, as speed has been directly proportional to the force applied.
Thus, to maintain the object at a constant speed, the force applied to the object has been reduced.
So, in order to move an object at a constant speed after increasing the length of the rope, less force is required because the force is inversely proportional to the radius of the circular orbit. Thus option C is correct.
For more information about the circular motion, refer to the link:
https://brainly.com/question/1388042
when two substance mixed together what does not indicate that a chemical reaction has
Answer:
When two substances are mixed together, a color change is observed. This observation is not enough evidence that there is a chemical reaction happening because color changes are not indicators of chemical reaction:
does anyone know the answers to these ?
Answer:
Q1. a
Q2. a
Explanation:
mass is not a vector quantity and west i 90 degrees more than south
Explanation:
massthe angle between vector A and b is 90and B is shorter than AIf you kick a soccer ball and a bowling ball with the sarne force, the soccer ball
will travel farther because
1- a body at rest tends to stay at rest while a body in motion tends to stay in motion unless acted in by an unbalanced force
2- as mass increases, acceleration decreases
3- for every action, there is an equal and opposite reaction.
The mass of the bowling ball is more hence the acceleration would be less for the bowling ball so, option 2 is correct.
What is Force?In mechanics, a force is any action that has the potential to change, maintain, or deform a body's motion. The three principles of motion outlined by Isaac Newton in his Principia Mathematica are frequently used to illustrate the concept of force (1687).
Newton's first law states that a body at rest or moving uniformly in a straight line will stay in that state until a force is applied to it. According to the second law, a body will accelerate (change in velocity) in the direction of any external force acting on it.
The mass of the bowling ball is more hence the vertical force is more on the bowling ball thus, it will travel less in the horizontal direction.
To know more about Force:
https://brainly.com/question/13191643
#SPJ2
A simple machine where an inclined plane is wrapped in a spiral is called a centripetal ramp.
T.
True
F.
False
Answer: False
Explanation:
In flight, a rocket is subjected to four forces; weight, thrust, lift, and drag. Forces are vector quantities that have both a magnitude
and a direction. Imagine that the rocket is about to lift off the launch pad. According to Newton's third law of motion, what force is
critical to the success of its upward motion?
A)
drag
B)
Lift
c)
thrust
D)
weight
Answer:
thrust
Explanation:
Answer:
thrust
Explanation:
What does aerospace engineering have to do with physics
An example of gravitational potential energy is the energy of:
a. any chemical
b. any object at a height
c. all moving objects.
Lab work
Part 1-Prove distance from the object to the mirror is the same as 4 trails. ??
Part 2-Show Image by Reflection and Refraction and also calculate the angle of Refraction with the help of snells law. ??
Answer:
The distance between the object and the mirror is X/2
Explanation:
If we look into a plane mirror, we see the image of our face situated behind the mirror. Now, if we move backwards, the image also moves backwards in the mirror so that it is always at the same distance behind the mirror as our face is in front of the mirror. Thus, the image I in a plane mirror is as far behind the mirror as the object O is in front of it. In other words, the distance of the image from the plane mirror is equal to the distance of the object from the plane mirror. We will prove this fact by using the laws of reflection and simple geometry.
From the second law of reflection, we have:Angle of incidence = Angle of reflection
So, NAO = NAX (angle i = angle r)
It is clear that the triangles MIA and MOA are congruent triangles and, therefore, their corresponding sides should be equal. Thus :
IM = OM
MA is a common side to both triangles
Now, OM represents the distance of object from the mirror, and IM represents the distance of image from the mirror .
So, we can now say that:
Distance of image from mirror = Distance of object from mirror
Does the pH change if you have a greater volume of the substance?
Yes, the pH of the solution will change. For an acid, it will increase and for a base, it will decrease
What is pH ?This is simply a measure of the acidity / alkalinity of a solution.
The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration
Mathematically, it expressed as
pH = –Log [H⁺]
The molarity of Hydrogen ion [H⁺] is given by
Molarity of [H⁺]= mole of [H⁺] / Volume
From the formula, we can see that the molarity is inversely proportional to the volume.
Thus an increase in the volume will decrease the molarity of [H⁺]. This also will affect the pH.
However, it should be noted that as the pH increases, pOH decreases and as pH decreases, pOH increases.
Learn more about pH:
https://brainly.com/question/3709867
#SPJ2
are y'all into spirituality ?
Answer:
I'm christian
Explanation:
A block of dimensions 5m by 4m by 6m has a mass of 10kgs .what is it's density
Explanation:
soln:
given,
dimensions(l,b,h)=5mx4mx6m
mass(m)=10 kg
density(d)=?
we know,
d=m/v
or,d=10/5*4*6
•°•d=1/12kg/m^3
A jeep starts from the state of rest. If its velocity becomes 60 km/hr in 5 minutes, (i)
What is the acceleration of the jeep? (ii) What is the distance covered by the jeep?
Answer:
acceleration= velocity/time
60km/hr = 60 km /60 mins = 1km/min so accn = 1km/5= 1000m/5 = 200m/m
v²= u²+2as
(1000)² = 0²+ 2 x 200 x s
(1000)²/400= s
2500m
Calculate the amount of energy a 3 kg ball on top of 10 m hill will have. Show your work with the correct ending units.
Answer:
This question is hard I will edit my answer when I find the answer
Explanation:
the surface of the earth is constantly changing. which of these findings provides the best evidence that the crustal surface of earth has changed over time?
ushi wygunu geygo sieta?
