Answer:
-50JExplanation:
What is the first law of thermodynamics?
"The first law of thermodynamics state that energy is conserved"
the expression bellow is the Change in internal energy of a system
Change in internal energy of a system
= heat put into the system - work done by the system on its surroundings,
or
ΔU = ΔQ - ΔW.
given data
Work done=125J
Heat= 75J
change=?
Substituting we have
ΔU = 75- 125
ΔU = -50J
"ΔQ is positive if heat flows into the system, negative if it flows out of the system.
ΔW is positive if the system does work on its surroundings and it is negative if work is done on the system. "
The spacecraft that have visited the outer planets have all flown close to inner planets (Venus, for example), often more than once, as part of their journeys. What was the primary reason for this?
Answer:
1) The outer planets happened to have been on the far side of the sun, so the shortest route passes the inner planets
Explanation:
All the planets revolve around the sun in a circular orbital. The orbits of Mercury, Venus, Earth, and Mars are tightly held with sun as they are very close to the sun and revolve faster in comparison to outer planet Jupiter, Saturn, Uranus, and Neptune.
Because of the shortest distance between the sun and inner planets, the spacecraft is able to visit the inner planet more than once while outer planets are very far from the sun and revolve around a large orbit, so the spacecraft visited the outer planets less than the inner planet.
Hence, the correct answer is "1".
The exchange of oxygen and carbon dioxide takes place through the capillary wall.
True
False
Explanation:
It mainly flows blood to arteries of heart but the answer is true.. because it also exchange oxygen,nutrient etc..
A 11.8-kg cylinder rolls without slipping on a rough surface. At an instant when its center of gravity has a speed of 10.4 m/s, determine the following. (a) the translational kinetic energy of its center of gravity J (b) the rotational kinetic energy about its center of gravity J (c) its total kinetic energy J
Answer:
1. 638.144j
2. 319.072 j
3. 957.216 j
Explanation:
M = 11.8 kg cylinder
V = speed of center of gravity = 10.4m/s
A.
Translational kinetic energy
= 1/2mv²
1/2x 11.8kg x 10.4²
= 11.8x108.16/2
= 1276.288/2
= 638.144 J
This is the translational energy
B.
Rotational energy
1/2Iw²
I = mv²/2
w = v/r
When we substitute
1/2[mv²/2][v/r]²
= 1/4mv²
= 1/4 x 11.8 x 10.4²
= 1276.288/4
= 319.072
This is the rotational energy
C
Total kinetic energy.
We add the values of A and B above to get this.
638.144 J + 319.072 J
= 957.216J
Find the terminal velocity of a spherical bacterium (diameter ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be .
Complete Question
Find the terminal velocity of a spherical bacterium (diameter [tex]2.00 \mu m[/tex] ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be [tex]1.10 *10^{3} \ kg/m^3[/tex]
Answer:
The value is [tex]v_t = 2.38*10^{-6} \ m/s[/tex]
Explanation:
From the question we are told that
The diameter of the spherical bacterium is [tex]d = 2.0\mu m = 2.0 *10^{-6} \ m[/tex]
The density of the bacterium is [tex]\rho =1.10 *10^{3} \ kg/m^3[/tex]
Generally the radius is mathematically represented as
[tex]r = \frac{d}{2}[/tex]
=> [tex]r = \frac{2.0 *10^{-6}}{2}[/tex]
=> [tex]r = 1.0*10^{-6}[/tex]
Generally the volume is mathematically represented as
[tex]V = \frac{4}{3} * \pi * r^2[/tex]
=>[tex]V = \frac{4}{3} * 3.142 * (1.0*10^{-6})^3[/tex]
=>[tex]V = 4.189 *10^{-18} \ m^3[/tex]
Generally the mass is mathematically represented as
[tex]m = V * \rho[/tex]
=> [tex]m = 4.189 *10^{-12} * 1.10 *10^{3}[/tex]
=> [tex]m = 4.608 *10^{-15} \ kg[/tex]
Generally the terminal velocity is mathematically represented as
[tex]v_t = \frac{m * g}{ 6\pi * r * \eta}[/tex]
Here [tex]\eta[/tex] is the viscosity of water with value [tex]\eta = 1.005 *10^{-3} \ kg/m\cdot s[/tex]
So
[tex]v_t = \frac{4.608 *10^{-15} * 9.8}{ 6 * 3.142 *1.0*10^{-6} * 1.005 *10^{-3}}[/tex]
=> [tex]v_t = 2.38*10^{-6} \ m/s[/tex]
what is it? and explain pls
The velocity at which an object is sent moving and the mass of the object both play a hand in the level of kinetic energy that object produces. Mass and kinetic energy have a positive relationship, which means that as mass increases, kinetic energy increases, if all other factors are held constant.
what is the average speed of a student 100cm/s Bernard 150 cm/s Chloe 50 cm/s Dev 75 cm/s Eduardo 125cm/s
Answer:
100cm/s
Explanation:
Given the speed of the following students;
Bernard 150 cm/s
Chloe 50 cm/s
Dev 75 cm/s
Eduardo 125cm/s
Their average speed of a student will be the mean of their individual speed as shown:
Average speed = 150+50+75+125/4
Average speed = 400/4
Average speed = 100
Hence the average speed of a student is 100cm/s
A pilot wants to fly north. The plane has an air speed of
350 km/h. There is a 25 km/h wind blowing to the west.
(a) What is the plane's velocity relative to the ground?
(b)What is its heading?
Explain me in details. I’ll give u the brainliest if you give me the right answer.
Answer:
A? Cause is needs the Velocity more than the Heading.
What best describes a bar magnet
Answer:Bar magnets are permanent magnets as opposed to electromagnets
A solid sphere, with a mass of 3 kg, is rolling across a horizontal floor without slipping. The sphere has 8.4 J of total kinetic energy and has a center of mass velocity of 2 m/s. Calculate the rotational kinetic energy of the solid sphere.
Answer:
2.4 J
Explanation:
The total kinetic energy of the solid sphere = rotational kinetic energy + translational kinetic energy
KE(total) = KE(rot) + KE(trans)
KE(rot) = KE(total) - KE(trans)
Since its total kinetic energy KE' = 8.4 J and its mass, m = 3 kg and the velocity of its center of mass, v = 2m/s, KE(trans) = 1/2mv² = 1/2 × 3 kg × (2 m/s)² = 3 kg × 2 m²/s² = 6 kgm²/s² = 6 J
So, KE(rot) = KE(total) - KE(trans)
Substituting the values of the variables, we have
KE(rot) = 8.4 J - 6 J
KE(rot) = 2.4 J
So, the rotational kinetic energy of the solid sphere is 2.4 J
The rotational kinetic energy of the solid sphere will be "2.4 J".
Kinetic energyAccording to the question,
Total Kinetic energy, KE' = 8.4 J
Mass, m = 3 kg
Center of mass's velocity, v = 2 m/s
Now,
KE(trans) = [tex]\frac{1}{2}[/tex]mv²
By substituting the values,
= [tex]\frac{1}{2}[/tex] × 3 × (2)²
= [tex]\frac{1}{2}[/tex] × 3 × 4
= 6 kgm³/s² or,
= 6 J
We know the relation,
→ KE(rot) = KE(total) - KE(trans)
By putting the values,
= 8.4 - 6
= 2.4 J
Thus the approach above is correct.
Find out more information about kinetic energy here:
https://brainly.com/question/25959744
What role do planetesimals play in the origin of the planets?
Find the electric field due to an infinite plane of positive charge with uniform surface charge density
Answer:
Explanation:
The Electric field due to an infinite plane of positive charge with uniform surface charge density can be derived a s follows
let us assume An infinite positively charged sheet and lets take a cylindrical gaussian surface on this surface which is perpendicular to this plane of sheet
we know that positive charge electric field lines will be perpendicular to this sheet surface will be perpendicular to the cylindrical surface
applying gauss law
[tex]Electric field * Area =[/tex] [tex]charge/epsilon\\[/tex]
also sigma=Q/A ⇒ Q=sigma*A
so on one face
E*A=sigma*A/epsilon
also we notice this electric field on one face of the sheet is exactly equal to that on the another face hence electric field will be twice
2E*A=sigma*A/epsilon
final result
[tex]E= sigma/2*epsilon[/tex]
The magnetic dipole moment of Earth has magnitude 8.00 × 1022 J/T. Assume that this is produced by charges flowing in Earth's molten outer core. If the radius of their circular path is 3470 km, calculate the current they produce
Answer:
Explanation:
Dipole moment of a coil carrying current i with area A
M = i A , M is magnetic moment , i is current and A is area of the coil.
A = π R²
= 3.14 x ( 3470 x 10³ )²
= 3.78 x 10¹³ m²
8.00 x 10²² = 3.78 x 10¹³ x i
current i = 8.00 x 10²² / 3.78 x 10¹³
= 2.11 x 10⁹ A .
Starting from rest, a 94-kg firefighter slides down a fire pole. The average frictional force exerted on him by the pole has a magnitude of 750 N, and his speed at the bottom of the pole is 3.1 m/s. How far did he slide down the pole
Given that,
Mass of a firefighter, m = 94 kg
Frictional force, F = 750 N
Speed at the bottom of the pole is 3.1 m/s
It is required to find the distance he slide down the pole.
Using Work-energy theorem,
initial potential energy = final kinetic energy + work done
[tex]mgh=W+\dfrac{1}{2}mv^2[/tex]
[tex]mgh=Fh+\dfrac{1}{2}mv^2[/tex]
Solving for h, such that :
[tex]h(mg-F)=\dfrac{1}{2}mv^2\\\\h=\dfrac{1}{2(mg-F)}mv^2\\\\h=\dfrac{1}{2(94(9.8)-750)}\times 94\times (3.1)^2\\\\h=2.63\ m[/tex]
So, he will slide 2.63 m down the pole.
Using five or more sentences, describe petroleum and what it is used for.
(I might mark brainliest if it is a good response) :D
Answer:
A liquid mixture of hydrocarbons that is present in certain rock strata and can be extracted and refined to produce fuels including gasoline, kerosen, diesal oil. :)
Explanation:
Yea mark brainleist pls
the weight of a box having a mass of 100kg is blank N.
Answer:
What is the answer we are supposed to be finding?
Explanation: Your answer is 980.7 if you are converting kilograms to Newtons
Does heat and temperature depend on the other or are they totally separate ideas? Explain.
Answer:
What heat means in thermodynamics, and how we can calculate heat using the heat ... Scientists define heat as thermal energy transferred between two systems
Explanation:
thermal energy
A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.
Answer:
-62.02πrads/sec^2
Explanation:
A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.
We need to convert to SI unit
9.549rev/ min= 1rad/sec
Then to convert angular speed of 3,550 rev/min to rad/sec
( 1 rad/sec)/9.549rev/min = x/5600rev/min
Then
(3,550 rev/min)/(9.549rev/min)= 371.77rad/sec
=118.4πrad/sec
6.823rad= 1rev
52.0 revolutions = 52×6.823= 354.796rads
= 113πrads
We will use expresion below to calculate our angular acceleration
w^2 - w^2(0)= 2α¢
Where w= angular speed
w(0)= initial angular
If final angular speed= 0
α=-w^2(0)/2¢
α=(-118.4π)^2/(2×113)
=-14018.56/226
-62.02πrads/sec^2
You can't always see electromagnetic waves, but they are found throughout
the universe. There are only a few waves that are visible to the human eye.
Electromagnetic radiation is used to meet our needs and wants. It makes
important things — like medical imaging, reheating food and cell phones
possible. Radiation can be helpful for sending texts, but it's not always a
good thing. The sunburn you get sitting on the beach is caused by
electromagnetic radiation, too.
The author of this passage would most likely agree with which of the following
statements?
A
Scientists do not know very much about electromagnetic waves.
B
Electromagnetic radiation can be both helpful and harmful to humans.
с
People understand electromagnetic waves better than ocean waves.
D
Electromagnetic radiation is more harmful than it is helpful.
The author of this passage is focusing on both the merits and demerits of electromagnetic waves. Thus, he agree with the statement that electromagnetic radiation can be both helpful and harmful to humans.
What are electromagnetic waves?Electromagnetic waves are transformation of energy and they are travelling with a combined electric field and magnetic field. There are various kinds of electromagnetic waves namely, ultraviolet, radio waves, microwaves x-rays etc.
All these waves have significant applications in various fields. Mostly in medical fields. They are used for diagnosing, cancer treatments drug optimization etc.
However, these waves are highly energetic and harmful too. Direct and elongated exposure to these waves may cause severe health risks including cancer.
The author addresses the advantages and disadvantages of the electromagnetic waves. Thus, option B is correct.
To find more on electromagnetic waves, refer here:
https://brainly.com/question/3101711
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