Answer:
Explanation:
Speed = Distance/Time
Given
Distance = 200km
Total speed = 100+50 = 150km/hr
Time = Distance/Speed
Time = 200/150
Time = 1.33hr
b) Average speed in km/hr is 150km/hr
Convert to m/s
150km/hr = 150 * 1000 m/1 * 3600s
150km/hr = 150,000/360
150km/hr = 416.67m/s
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..
The line segment joining the mid point of any side with the opssosite vertex is called?
In a single process, a system does 125 J of work on its surroundings while 75 J of heat is added to the system. What is the internal energy change for the system
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. "
A hockey puck is sitting stationary on a frozen pond. A player slaps the puck, accelerating it from rest to 45 m/s in 0.03 s. What is the average force on the hockey puck while it is in contact with the stick
Answer:
F = 240 N
Explanation:
Let the mass of the puck, m = 160 g = 0.16 kg
Initial speed, u = 0 (at rest)
Final speed, v = 5 m/s
Time, t = 0.03 s
We need to find the average force on the hockey puck while it is in contact with the stick. Force is given by the formula as follows :
F = ma, a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{0.16\times (45-0)}{0.03}\\\\F=240\ N[/tex]
So, the average force is 240 N.
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
How many atoms of each element are
needed to bond
Ca + F
k+ S
Li+ O
Answer:
How many electrons whill each element gain or lose in forming an ion? ... to form an ionic compound? a. Al and O b. H and N c. I and K d. F and Cl e. Li and S ... free flowing, but the valence electrons in ionic crystals have a strong bond with their atoms ... necessary to attain the electron configuration of what kind of element
Explanation:
Use the drop-down menus to identify the parts of the diagram labeled A, B, and C.
Label A
Label B
Label C
Answer:
b
Explanation:
bcuz I looked it up and it was on there
Answer:
the answers are:
- cool fluid sinks
- warm fluid rises
- convention current
Explanation:
Im late but mark me as brainliest for helping you out cause the one on top is clueless
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 .
A 10-kg object is hanging by a very light wire in an elevator that is traveling upward. The tension in the rope is measured to be 75 N. What are the magnitude and direction of the acceleration of the elevator
Answer:
2.31m/s² downwards
Explanation:
The sum of forces on the object is expressed as;
T-W
T is the tension on the rope
W is the weight
According yo Newton's second law:
T-W= ma
m is the mass
a is the acceleration
Given
T = 75N
W = mg = 10×9.81
W = 98.1N
Substitute
75-98.1 = 10a
-23.1 = 10a
a = -23.1/10
a = -2.31m/s²
The magnitude of the acceleration is 2.31m/s² and directions is downwards
Anybody good at science math?
Answer:
the pressure is: 200 N/m^2
Explanation:
Recall that pressure is defined as force (F) per unit of area (A), which in math terms is:
P = F / A
Then, if the force is 2.4 N , and the area of the glass' bottom is 0.012 m^2, then the pressure is:
P = 2.4 / 0.012 = 200 N/m^2
Answer:PLEASE HELP ME
Explanation:
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
If a coil stays at rest in a very large static magnetic field, no emf is induced in this coil. Group of answer choices True False
Answer:
True
Explanation:
Faraday's Law says that there is a emf induced in a conductor when the vector flux of the magnetic field across it changes in time.This can be true due to one of two facts, either the magnitude of the magnetic field changes in time, or the area through which the flux occurs changes due to the movement of the object.In this case, due to the magnetic field is constant, and the coil stays at rest, there is no possible change in flux, so emf induced is zero.I NEED HELP ASAP! PLS! <3
Answer:
a = - 1 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} = v_{o} +(a*t)[/tex]
where:
Vf = final velocity = 0 (velocity at 10 seconds)
Vo = initial velocity = 4 [m/s]
a = desacceleration [m/s²]
t = time = 4 [s]
From the graph, we can deduce that between the second 10 and the second 6 there are (10-6) = 4 seconds difference.
In the second 6, the velocity is 4 [m/s]
0 = 4 + (a*4)
4*a = -4
a = - 1 [m/s²]
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
#SPJ2
25 POINTS FIRST CORRECT GET BRAINLIEST!!!!!!!!!!!!!!!!1
Answer:
carbon isnt 12
Explanation:
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.
Find relationship between‘ g’and ,‘G’
Answer:
The acceleration on an object due to the gravity of any massive body is represented by g (small g). The force of attraction between any two unit masses separated by unit distance is called universal gravitational constant denoted by G(capital g). The relation between G and g is not proportional.
Explanation:
Which atoms are deflected the most by the magnetic field?
Answer:
Different ions are deflected by the magnetic field by different amounts. The amount of deflection depends on: the mass of the ion. Lighter ions are deflected more than heavier ones.
A physicist is creating a computational model of a falling person before and after opening a parachute. What boundary conditions would be important here?
the air resistance encountered as the person falls
the speed at which the person falls
the change in kinetic and potential energy
the location where potential energy is zero
Answer:
Air resistance
Explanation:
Air resistance encountered as the person falls
Answer:
the location where potential energy is zero
Explanation:
A woman runs up a flight of stairs. The gain in her gravitational potential energy is U. If she runs up the same stairs with twice the speed, what is her gain in potential energy?
Answer:
U
Explanation:
The change in gravitational potential energy only depends of the difference in height (in this case the number of stairs), so as the height remained the same, her gain in potential energy remained the same, independent from her climbing speed.11.
A current of 67 amps runs through a resistor of 37 ohms, how much voltage is lost?
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]
Problem 9.20 A sphere of uniform density with mass 18 kg and radius 0.8 m is spinning, making one complete revolution every 0.4 s. The center of mass of the sphere has a speed of 8 m/s. (a) What is the rotational kinetic energy of the sphere
Answer:
K = 567.91 J
Explanation:
Given that,
Mass of sphere, m = 18 kg
Radius of a sphere, r = 0.8 m
It makes one complete revolution every 0.4 s.
The speed of center of mass of the sphere is 8 m/s
We need to find the rotational kinetic energy of the sphere. It is given by the formula as follows :
[tex]K=\dfrac{1}{2}I\omega^2[/tex]
I is moment of inertia,
[tex]I=\dfrac{2}{5}mr^2\\\\I=\dfrac{2}{5}\times 18\times (0.8)^2\\\\I=4.608\ kg-m^2[/tex]
[tex]\omega[/tex] is angular speed
[tex]\omega=\dfrac{2\pi }{0.4}\\\\=15.7\ rad/s[/tex]
So,
[tex]K=\dfrac{1}{2}\times 4.608\times (15.7)^2\\\\K=567.91\ J[/tex]
So, the rotational kinetic energy of the sphere is 567.91 J.
The rotational kinetic energy of the sphere is 710.8 J.
Moment of inertia of the sphereI = ¹/₂mr²
I = 0.5 x 18 x (0.8)²
I = 5.76 kgm²
Angular speed of the sphereω = 2πf
ω = 2π x (1/0.4s)
ω = 15.71 rad/s
Rotational kinetic energyK.E = ¹/₂Iω²
K.E = 0.5 x (5.76) x (15.71)²
K.E = 710.8 J
Thus, the rotational kinetic energy of the sphere is 710.8 J.
Learn more about rotational kinetic energy here: https://brainly.com/question/25803184
For a smooth sphere with a 11 cm diameter thrown through air (air density of 1.25 kg/m3, air viscosity 1.83*10-5 Pa-s), what is the speed (in cm/s) when the Reynolds number is 2,511
Answer:
u = 0.334 m/s
Explanation:
The formula for Reynold's number is given as follows:
Re = ρuL/μ
where,
Re = Reynold's Number = 2511
ρ = Density of air = 1.25 kg/m³
μ = Dynamic Viscosity of Air = 1.83 x 10⁻⁵ Pa.s
L = Characteristic Length = Diameter of Sphere = 11 cm = 0.11 m
u = Speed = ?
Therefore,
2511 = (1.25 kg/m³)(u)(0.11 m)/(1.83 x 10⁻⁵ Pa.s)
u = (2511)/(7513.66 s/m)
u = 0.334 m/s
What role do planetesimals play in the origin of the planets?
how much kinetic energy does a 2,000 kg car have when its traveling 5 m/s
Answer: 5000J
Explanation:
equation for kinetic energy is k=(mv^2)/2
plug in your mass and velocity
k = (2000*5^2)/2 = 5000J
How much time is required for an airplane to reach its takeoff speed of 77m/a if it starts from rest and its average acceleration is 8.2m/s^2?
Answer:
The time required is t = 9.39 [s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o} +(a*t)[/tex]
where:
Vf = final velocity = 77 [m/s]
Vo = initial velocity = 0
a = acceleration = 8.2 [m/s²]
t = time [s]
The initial speed is zero, since the airplane begins its movement from rest. The initial speed is zero, since the aircraft begins its movement from rest. Another important fact is that the sign of acceleration is positive since the plane is accelerating, that is, its speed is increasing.
Now replacing:
77 = 0 + (8.2*t)
t = 9.39 [s]
Write the electric field strength EE in all three regions as a function of rr: for r>r2r>r2, r1
Answer:
Explanation:
See attachment
Find the magnitude of the Sun's gravitational force on the Earth when the Earth is at perihelion and at aphelion. The perihelion and aphelion distances are 1.48 ✕ 1011 m and 1.52 ✕ 1011 m, respectively.
Answer:
Explanation:
Force F = GMm / R²
mass of the sun M = 1.99 x 10³⁰ kg
mass of the earth = 5.97 x 10²⁴ kg
value of G = 6.67 x 10⁻¹¹
for perihelion point R = 1.48 x 10¹¹ m
Force = 6.67 x 10⁻¹¹ x 1.99 x 10³⁰ x 5.97 x 10²⁴ / ( 1.48 x 10¹¹ )²
= 36.17 x 10²¹ N
for aphelion point R = 1.52 x 10¹¹ m
Force = 6.67 x 10⁻¹¹ x 1.99 x 10³⁰ x 5.97 x 10²⁴ / ( 1.52 x 10¹¹ )²
= 34.29 x 10²¹ N
How far will a motorcycle that accelerates at 1.28 m/s2 travel as its velocity increases from 10.0 m/s to 20.0 m/s?
Answer:
117
Explanation:
