Answer:
Steady-state theory, in cosmology, a view that the universe is always expanding but maintaining a constant average density, with matter being continuously created to form new stars and galaxies at the same rate that old ones become unobservable as a consequence of their increasing distance and velocity of recession.
Cosmic inflation is a faster-than-light expansion of the universe that spawned many others. ... Cosmic inflation solves these problems at a stroke. In its earliest instants, the universe expanded faster than light (light's speed limit only applies to things within the universe).
a stone weight 490 N on a planet whose acceleration due to gravity is half that of the Earth. Calculate (1) the mass of a stone
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Acceleration due to gravity on that planet is half than that of om earth ~
that is ~
[tex] \dfrac{9.8}{2} \: \: m/ {s}^{2} [/tex][tex]4.9 \: \: m/s {}^{2} [/tex]And it's weight is equal to ~
[tex]490 \: \: N[/tex]now, As we know ~
[tex]f = m \times g[/tex]here ,
f = Weight = 490 Newtonsm = mass of stone = ?g = Acceleration due to gravity on that planet = 4.9 m/s²let find the mass of stone ~
[tex]490 = m \times 4.9[/tex][tex]m = \dfrac{490}{4.9} [/tex][tex]m = 100 \: \: kg[/tex]Mass of the stone is 100 kg ~
I hope it helped
A 0.60-kgkg ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.3 mm on a frictionless horizontal surface. Part A If the cord will break when the tension in it exceeds 60 NN , what is the maximum speed the ball can have
11.4 m/s
Explanation:
The cord will break when the centripetal force exerted on it meets or exceeds the maximum tension [tex]T_{max}[/tex] that it can handle.
[tex]T_{max} = m\dfrac{v_{max}^2}{r}[/tex]
Solving for [tex]v_{max},[/tex] we get
[tex]v_{max}^2 = \dfrac{rT_{max}}{m}[/tex]
or
[tex]v_{max} = \sqrt{\dfrac{rT_{max}}{m}} =\sqrt{\dfrac{(1.3\:\text{m})(60\:\text{N})}{(0.6\:\text{kg})}}[/tex]
[tex]\:\:\:\:\:= 11.4\:\text{m/s}[/tex]
What are cyclotrons and how are they used?
7) Germanium, element 32 on the Periodic Table, is shown here. If a proton is added to the nucleus of germanium, what outcome(s) would occur? Select ALL That apply.
A) The atom would increase in mass but would remain germanium.
B) The atom would become arsenic and have different properties.
The atom would remain germanium, but it would have a positive charge.
D) The atom would increase in mass and have different elemental properties.
E) The atom would expel a neutron to maintain a constant mass and chemical properties.
Addition of a proton to germanium will convert it to arsenic (element 33) having different properties.
The atomic number of an atom is the number of protons in the nucleus of the atom. The atomic number serves as the identity of an atom. If the atomic number is changed by adding or removing protons, the identity of that atom changes.
Hence, when a proton is added to germanium, the atom would become arsenic (element 33) and have different properties.
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Answer: Its B and D
I had the same question on usatestprep
b) A satellite is in a circular orbit around the Earth at an altitude of 1600 km above the Earth's surface. Determine the orbital period of the satellite in hours. [3]
Explanation:
The orbiting period of a satellite at a height h from earth' surface is
T=2πr32gR2
where r=R+h.
Then, T=2π(R+h)R(R+hg)−−−−−−−−√
Here, R=6400km,h=1600km=R/4
T=2πR+R4−−−−−−√R(R+R4g)−−−−−−−−−⎷=2π(1.25)32Rg−−√
Putting the given values,
T=2×3.14×(6.4×106m9.8ms−2)−−−−−−−−−−−−√(1.25)32=7092s=1.97h
Now, a satellite will appear stationary in the sky over a point on the earth's equator if its period of revolution around the earthh is equal to the period of revolution of the earth up around its own axis whichh is 24h. Let us find the height h of such a satellite above the earth's suface in terms of the earth,'s radius.
Let it be nR.Then
T=2π(R+nR)R(R+nRg)−−−−−−−−−−√
=2π(Rg)−−−−−√(1+n)32
=2×3.14(6.4×106m/s9.8m/s2)−−−−−−−−−−−−−−−⎷(1+n)32
(5075s)(1+n)32=(1.41h)(1+n)32
For T=24h, we have (24h)=(1.41h)(1+n)32
or (1+n)32=241.41=17
or 1+n(17)23=6.61
or n=5.61
The height of the geostationary satellite above the earth's surface is nR=5.61×6400km=6.59×104km.
A 10kg crate sits at rest on a rough flat surface. Astudent decides to pull the crate by attaching a rope at a 37 degree angle. Although the student pulls the rope with a force of 600 newtons, the coefficient of kinetic friction is large and has the force the student applies remains constant, how much time after he begins pulling the crate will it take before the crate has traveled a distance of 1.0 meter?
Answer:
Explanation:
Normal force of the surface on the box will be
N = mg - Fsinθ
Ν = 10(9.8) - 600sin37
N = -263
As normal force cannot be less than zero, the applied force lifts the crate off the surface.
Now it's just a matter of finding the acceleration
In the horizontal direction, the acceleration is
a = F/m
a = (600cos37) / 10
a = 47.9181... m/s²
the crate weight is mg = 10(9.8) = 98 N.
In the vertical direction the acceleration is
a = ((600sin37 - 98) / 10)
a = 26.3089... m/s²
total acceleration is
a = √(47.9181² + 26.3089²)
a = 54.6653... m/s²
s = ½at²
t = √(2s/a)
t = √(2(1.0)/54.6653)
t = 0.19127...
t = 0.19 s
Please Help
A car of mass 400 kais sped up from 10m/s to 30m/s in a time of 15 seconds
What is the starting KE?
what is the ending KE?
what is the work done to speed up the car?
what is the power of watts?
Explanation:
The initial kinetic energy [tex]KE_0[/tex] is
[tex]KE_0 = \frac{1}{2}mv_0^2 = \frac{1}{2}(400\:\text{kg})(10\:\text{m/s})^2[/tex]
[tex]\:\:\:\:\:\;\:= 2×10^4\:\text{J} = 20\:\text{kJ}[/tex]
The final kinetic energy [tex]KE[/tex] is
[tex]KE = \frac{1}{2}mv^2 = \frac{1}{2}(400\:\text{kg})(30\:\text{m/s})^2[/tex]
[tex]\:\:\:\:\:\:\:= 1.8×10^5\:\text{J} = 180\:\text{kJ}[/tex]
The work done W on the car is
[tex]W = \Delta{KE} = KE - KE_0[/tex]
[tex]\:\:\:\:\:\:\:= 180\:\text{kJ} - 20\:\text{kJ} = 1.6×10^5\:\text{J}[/tex]
The power expended P is
[tex]P = \dfrac{W}{t} = \dfrac{1.6×10^5\:\text{J}}{15\:\text{s}} = 10667\:\text{Watts}[/tex]
[tex]\:\:\:\:\:= 10.7\:\text{kW}[/tex]
What is sixth state of matter?
HELP PLS!!
A 3 kg mass is raised a distance of 14 m above the earth by a vertical force of 93 N.
a
The gain in potential energy of the mass, to 3 significant figures, is:
Hi there!
We know that:
U (Gravitational Potential Energy) = mgh
Where:
g = acceleration due to gravity (m/s²)
m = mass (kg)
h = height/displacement (m)
Plug in the values:
U = 3 × 9.8 × 14 = 412 J
What is the direction of the torque produced on the crankset by the 2-kg mass attached to the pedal bar
A Torque is a twisting force, or turning moment, it is a vector quantity with both magnitude and direction e.g Turning the handle of a cork-screw clockwise and then counterclockwise will advance the screw first inward and then outward By convention, counterclockwise torques are positive and clockwise torques are negative.
The direction is perpendicular to both the radius from the axis and to the force. It is conventional to choose it in the right hand rule direction along the axis of rotation.
Counterclockwise is the positive rotation direction and clockwise is the negative direction.
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which materials are good for constructing bridges and tall buildings
Answer:
Cement, iron, and steel all work great!
A ball is thrown up onto a roof, landing 4 sec later at height of 20m above the release level. The balls path just before landing is angled at 60 degree with the roof.
a) find the horizontal distance d it travels.
b) what is the magnitude of the balls initial velocity?
c) what is the angle (relative to the horizontal) of the balls initial velocity?
Answer: 20
Explanation:
Is electrical energy the same or different from energy it takes to play a soccer game
Answer:
Diffrent
Explanation:
Electrical energy is electrical charges moving. When you play soccer kinetic energy is used. Kinetic energy is the movement of atoms, objects, and electrons.
A father (75 kg) was standing watching TV, minding his own business when one of his kids (20 kg) approached him at 2m/s heading at 0 degrees and jumped onto his back. Another kid (15 kg) approached him at 3m/s heading at 45 degrees to the first kid and also jumped on him at exactly the same time. Immediately after impact, in what direction did the group go (measured in degrees with respect to the first kid)
Answer:
Explanation:
Conservation of momentum
Let's say the first child was headed north
North momentum
75(0) + 20(2) + 15(3sin45) = (75 + 20 + 15)vn
vn = 0.6529 m/s
East momentum
75(0) + 20(0) + 15(3cos45) = (75 + 20 + 15)ve
ve = 0.28927 m/s
θ = arctan(0.28927/0.6529)
θ = 23.896...
θ = 24° east of north
1.25 is the closest to 1.04 or not I want to answer please. I think it's true, but I want to prove it scientifically, please.
Answer/Explanation:
It False, because if You Round Both of them..
1.25= 1.30
1.04= 1.00
it's like, 1 dollar and 4 cents; compared to 1 dollar and 25 cents. Obviously 25 cents is a lot more than 4 cents.
An airplane accelerates down a runway at 3.20 m/s2 for 32.8 s until is finally lifts off the ground. Determine the distance traveled before takeoff.
Answer:
The distance traveled before takeoff is 1720 m
Explanation:
Given:a = + 3.2 m/s²
t = 32.8 s
Vᵢ = 0 m/s
To Find:d = ?
Now,
d = Vᵢ × t + 0.5 × a × t²
d = (0 m/s) × (32.8 s) + 0.5 × (3.20 m/s²) × (32.8 s)²
d = 1720 m
Thus, The distance traveled before takeoff is 1720 m
-TheUnknownScientist 72
An object will begin moving from rest when acted upon by which forces?
A. Forces that are slightly less than the force of friction
B. Forces that result in a net force of zero
C. Forces that are equal and act in opposite directions
D. Forces that are greater in one direction than in any other direction
Answer:
D
Explanation:
Process of elimnination + it's the only one that makes sense
An object will begin moving from rest when acted upon by forces that are greater in one direction than in any other direction. Hence, Option (D) is correct.
What is force?The definition of force in physics is: The push or pull on a massed object changes its velocity. An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude.
When forces that are greater in one direction than in any other direction, resultant will be unbalanced forces. Unbalanced forces are those acting on a body when the net force acting on the body is greater than zero. The body alters its state of motion when unbalanced forces act on it.
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A cyclist on a training ride records the distance she travels away from home. The data only shows the first150 minutes of the ride before her cycling computer ran out of battery.
Answer:
A) 58 km
B) 30 mins
Explanation:
In pic details
graph in pic
Two trucks leave at different times (from the same place) headed for the same city. Both trucks arrive at the same time. Based on this information, which of the following sentences is true? Select one:
a. The trucks travelled the same distance in the same amount of time.
b. The trucks were traveling at the same average speed.
c. The trucks travelled different distances.
d. The truck that left later was travelling faster.
Answer:
d. The truck that left later was travelling faster
Explanation:
Both trucks travelled from the same place to the same place, meaning they both travelled the same distance;
They both arrive at the same time, but the second truck left later so it took less time to travel the distance than the first truck;
The only variable that can account for this difference is speed;
The one that left later, therefore, must have been going faster.
The car on this ramp starts from rest. When released, it
accelerates at a constant rate. It has an initial position of 12 cm
from the top of the ramp, and has an average velocity of 1.20 m/s
for a total of 1.80 s. Which is the correct final position of the car?
Answer:
Explanation:
s 0.12 + 1.20(1.80) = 2.28 m from the top.
A machine lifts a load of 100N through a vertical distance of 2m in seconds. What is the work done by machine?
Explanation:
In this chapter, we will study the important concepts of kinetic energy and the
closely related concept of work and power.
A- Kinetic Energy
Kinetic energy is a physical quantity, which is associated with the moving objects
and defined as:
K = ½ mv2
If the body is stationary (v=0), its kinetic energy is zero. The SI unit of kinetic
energy is kg.m2
/s2
or Joule (J), where 1 J=1 kg.m2
/s2
. Kinetic energy is a scalar
quantity.
B- Work
The work is defined as the ability to perform a force along a certain displacement.
There are different types of work as follows:
1- Work done by a constant force
The work done by the constant force F is given by the scalar product of the force F
and the displacement d.
WF = F.d = Fd cosθ
where θ is the angle between the force and displacement. The above equation means
that the work is the product of the displacement magnitude by component of the
force parallel to the displacement. Therefore, work is a scalar quantity (only
magnitude, no direction) and can be positive, negative, or zero. The SI unit of work
is (N.m) or joule (J) where 1 N.m = 1 J.
Special cases and remarks:
• If the angle between the force and displacement is zero (parallel), the work is
WF = F d (maximum work)
For the vertical part, W = (200 N) * (10 m) * cos (0 deg) = 2000 J. For the horizontal part, W = (50 N) * (35 m) * cos (0 deg) = 1750 J. The total work done is 3750 J (the sum of the two parts).
Two objects are a distance of 1.7 x 103 meters apart. One object has a mass of 3 x 107 kg and the other has a mass of 6 x 108. Determine the gravitational force between the objects.
Answer: You need to use Newton's law for the equation --->
Explanation: G × M × m / separation. Thats how youll get your answer !!
which of the following statements might be used to defend the Act of 1848
PLSSS HELP IT'S VERY IMPORTANT FOR ME WILL MAKE AS BRAINLIEST
Fill in the blank
Valence electrons are______
"The answer is not electrons in the outer shells that are not filled!!"
Answer:
negatively charged particle
valence electron is a electron of an atom, located in the outermost shell (valence shell ) of the atom, that can be transferred to or shared with another atom.
What is the frequency of a photon that has the same momentum as a neutron moving with a speed of 1000 m/sm/s
Explanation:
Since the neutron is only moving at 1000 m/s, we are going to ignore the relativistic effects on its mass and energy. The mass of a neutron in [tex]m_n = 1.67×10^{-27}\:\text{kg}[/tex] so its kinetic energy KE is
[tex]KE = \frac{1}{2}m_nv^2[/tex]
[tex]\:\:\:\:\:\:\:\:= \frac{1}{2}(1.67×10^{-27}\:\text{kg})(10^3\:\text{m/s})^2[/tex]
[tex]\:\:\:\:\:\:\:\:= 8.35×10^{-22}\:\text{J}[/tex]
A photon's energy E is defined as
[tex]E = h\nu[/tex]
where [tex]\nu[/tex] is the photon's frequency and h is the Planck's constant. Solving for the frequency, we get
[tex]\nu = \dfrac{E}{h} = \dfrac{8.35×10^{-22}\:\text{J}}{6.63×10^{-34}\:\text{J-s}}[/tex]
[tex]\:\:\:\:\: = 1.26×10^{12}\:\text{Hz}[/tex]
which is right around the infrared radiation range.
a load of 600 N is lifted using a first class lever applying an effort of 350 N. If the distance between the fulcrum and the effort is 60 cm and the distance between the load and the fulcrum is 30cm, calculate it's efficiency
Explanation:
(a) A machine is a device by which we can either overcome a large resistive force at some point by applying a small force at a convenient point and in a desired direction or by which we can obtain a gain in the speed.
(b) An ideal machine is a machine whose parts are weightless and frictionless so that which there is no dissipation of energy in any manner. Its efficiency is 100%, i.e. the work output is equal to work input.
Jack sits in the chair of a Ferris wheel that is rotating at a constant 0.120 rev/s . As Jack passes through the highest point of his circular part, the upward force that the chair exerts on him is equal to one-fourth of his weight.
Answer:
Explanation:
0.120 rev/s(2π rad/rev) = 0.24π rad/s
At the highest point of the arc, gravity must supply the required centripetal acceleration. As the normal force is 1/4 of his normal weight, then 3/4 of gravity acceleration must be used as centripetal acceleration
0.75g = ω²R
R = 0.75(9.81) / (0.24π)²
R = 12.942198...
R = 12.9 m
The radius of the circle is equal to 12.95m which is rotating with an angular velocity of 0.120 rev/s.
What is vertical circular motion?A body spins in a vertical circle so that its motion at different points is different from the motion of the body is said to be vertical circular motion.
The velocity and tension vary in maximum magnitude from the lowest to the highest position because of the effect of the gravitational force of the earth.
Given, the angular velocity of the Ferris wheel, ω = 0.120 rev/s
ω = 0.120 rev/s × 2π rad/rev
ω= 0.7536 rad/s
If r is the radius of the circle and 'm' is the mass of the jack.
From newton's second law of motion, the net force will be equal to
mg - N = mrω²
mg - (mg/4) = mrω²
r = 3g/4ω²
r = 3×9.81 / (4× 0.7536)
r = 12.95 m
Therefore, the radius of the circle in which the jack travels is equal to 12.95m.
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Your question is incomplete, most probably the complete question was,
Jack sits in the chair of a Ferris wheel that is rotating at a constant 0.120 rev/s. As Jack passes through the highest point of his circular part, the upward force that the chair exerts on him is equal to one-fourth of his weight. What is the radius of the circle in which Jack travels?
The 6 strings on a guitar all have about the same length and are stretched with about the same tension. The highest string vibrates with a frequency that is 4 times that of the lowest string. 1)If the strings are made of the same material, how would you expect the diameters of the lowest and highest strings to compare
Answer:
not sure i need points
Explanation:
A 5 kg box is sitting on a rough wooden surface. The coefficient of static friction between the box and surface is 0.6. If the normal force on the box is 50 N, calculate the force of friction which must be overcome to move the box. Round your answer to the nearest whole number.
The force of friction needed to overcome to move the box is 29.4N
According to Newton's second law;
[tex]\sum F_x = ma_x\\[/tex]
Taking the sum of force along the plane;
[tex]F_m -F_f = ma\\F_m -F_f = 0\\F_m=F_f = \mu R[/tex]
This shows that the moving force is equal to the frictional force
Given that
[tex]\mu = 0.6\\R = mg = 49N[/tex]
Get the frictional force;
Since
[tex]F_f = \mu R\\F_f = 0.6 \times 49\\F_f = 29.4N[/tex]
Hence the force of friction needed to overcome to move the box is 29.4N
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Velocity and Acceleration Quick Check
Item 1
Use this graph of velocity vs. time for two objects to answer the question.
Item 2
Item 3
С
Item 4
Item 5
D
velocity
time
Which statement makes an accurate comparison of the motions for objects C and D?
(1 point)
lol
Answer:it’s C
Explanation:
by using graph of velocity vs. time for two objects, Item 4 and Item 5 statement makes an accurate comparison of the motions for objects. thus option C is correct.
What is velocity ?
velocity is the rate of change of the position of the object with respect to reference and it is complicated but velocity is basically speeding a particular object in a specific direction.
Velocity is a vector quantity which means both magnitude (speed) and direction are combinedly define define velocity. The SI unit of velocity is meter per second (ms-1) and the magnitude or the direction of velocity of a body changes leads to acceleration.
Speed and velocity are the two closest term but the major difference between speed and velocity is that speed gives us an idea that the object with the faster rate of movement r where as velocity speed up as well as tells us the direction of the body
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