Answer:
Cement, iron, and steel all work great!
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
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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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:
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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6) The modern atomic model is called the _____.
A) central atom model
B) plum pudding model
C) nuclear atomic model
D) electron growth model
The modern atomic model is called the nuclear atomic model.
Therefore the correct answer is option C.
What are atomic models?There are many types of atomic models proposed in past based on their individual assumptions and the experimentations
John Dalton's atomic model.
The Plum Pudding Model, developed by J.J. Thomson,
Rutherford's model provided an explanation for the presence of a nucleus inside the atom.
In accordance with the current atomic model, atoms have a nucleus made up of protons and neutrons and an ethereal gradient or cloud surrounding them that houses electrons;
The modern atomic model is called the nuclear atomic model.
Thus, the correct answer is option C.
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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
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.
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.
why does air pressure decrease with increasing altitude?
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.
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 !!
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
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).
can anyone explain how to do it for me? i don't understand...
Answer:
15[m].
Explanation:
1) the required distance is AD, for more info see the attached picture.
2) [tex]AD=\sqrt{AA_1^2+A_1D^2} =\sqrt{81+144}=15[m].[/tex]
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.
What are cyclotrons and how are they used?
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]
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
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.
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.
which of the following statements might be used to defend the Act of 1848
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]
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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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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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
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
A ball is thrown vertically down from the edge of a cliff with a speed of 4 m/s, how high is the cliff, if it took 12 s for the ball to reach the ground?
I need the Formula
Hi there!
We can use the equation:
d = v₀t + 1/2at²
Where:
v₀ = initial velocity downward
a = acceleration due to gravity
t = time
Plug in given values:
d = 4(12) + 1/2(9.8)(12²)
d = 48 + 705.6 = 753.6 m
What is sixth state of matter?
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:
What is the birth rate of a population of 3000 chipmunks if 200 chipmunks are born each year?
o 0.022 births per chipmunk per year.
0.067 births per chipmunk per year.
O 0.82 births per chipmunk per year.
o 15 births per chipmunk per year.
Answer:
0.067 births per chipmunk per year
Explanation:
I took the test