Answer:
The astronaut is moving at a speed of 0.238 m/s in a direction opposite the direction of the water shot out.
Explanation:
We are given;
Mass of astronaut; m1 = 84 kg
Mass of water shoot out; m2 = 2 kg
Initial speed of astronaut; u1 = 0 m/s
Initial speed of water shoot out; u2 = 0 m/s
Final speed of shoot out; v2 = 10 m/s
From law of conservation of momentum, we can say that;
Initial momentum = final momentum
Thus;
m1•u1 + m2•u2 = m1•v1 + m2•v2
Where v1 is the final speed of the astronaut
Plugging in the relevant values, we get;
(84 × 0) + (2 × 0) = (84 × v1) + (2 × 10)
0 = 84v1 + 20
-20 = 84v1
v1 = -20/84
v1 = -0.238 m/s
The negative sign indicates that the astronaut is moving 0.238 m/s in a direction opposite the direction of the water shot out.
An object with a mass of 14 kg experiences a force of 12 N. What is the acceleration of the object? Help, please!! <3
Answer:
6/7 kg
Explanation:
We are given:
Mass of the object (m) = 14 kg
Force applied (F) = 12 N
Acceleration of the Object:
From newton's second law of motion, we know that:
F = ma
Replacing the variable with the given values
12 = 14 * m
m = 12 / 14 [dividing both sides by 14]
m = 6/7 kg
Hence, the Object has a mass of 6/7 kg
The loudness of a sound is the waves amplitude
True or false
Answer:
true i think
Explanation:
The amplitude of a sound wave determines its loudness or volume. A larger amplitude means a louder sound, and a smaller amplitude means a softer sound. In Figure 10.2 sound C is louder than sound B. The vibration of a source sets the amplitude of a wave.
Answer:
True
Explanation:
Look up the definition of amplitude
The velocity of a passenger relative to a boat is -vpb. The velocity of the boat relative to the river it is moving on is vbr. The velocity of the river to the shore is vrs. What is the velocity of the passenger relative to the shore
Answer:
vps = vbr + vrs - vpb
Explanation:
If the passenger were at rest, his speed relative to the shore will be identical to the boat's, as follows:vps = vbr + vrsAs he is moving in a direction opposite to the boat's, his velocity relative to the shore must be less than if he were at rest, in the same quantity that he was moving opposite to the boat, as follows:vps = vbr+ vrs -vpbMake a rule: How does the energy needed to move an electron to a higher energy level compare to the energy emitted when the electron moves back to the lower energy level
Answer:
Explanation:
Generally, the energy required to move an electron from one energy level to another energy level is referred to as quantum energy. An atom will absorb energy when it's electron(s) move from a lower energy level (ground state) to a higher energy level (excited state) and will emit energy when it's electron(s) move from a higher energy level to a lower energy level.
Since, electrons do not stay in the excited state forever, they indeed prefer the ground state and thus will always return to the ground state. When an electron thus return to the ground state, it sheds off the excess energy that took it to the excited state thus it can be said that more energy is required to take an electron to it's excited state.
Answer:
Explanation:
When an atom absorbs energy it will go up x number levels. When it admits energy it will go down to its previous energy level and emit the same exact amount of energy that was absorbed.
Write the expression for the frequency of a mass m on a spring moving horizontally. Suppose that k is the spring constant. Express your answer in terms of some or all of the variables k, m, g.
Answer:
[tex]f=1/2\pi *\sqrt{k/m}[/tex]
Explanation:
This is the equation of the frequency of a spring in the horizontal direction.
What amount of heat is absorbed by 257 g of water heated from 18° C to 63° C? The specific heat of water is 4.18 J/g°C.
Answer:
Q = 48341.7 Joules.
Explanation:
Given the following data;
Mass, m = 257g
Initial temperature, T1 = 18°C
Final temperature, T2 = 63°C
Specific heat capacity of water, c = 4.18 J/g°C.
*To find the quantity of heat absorbed*
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2 - T1
dt = 63 - 18
dt = 45°C
Substituting the values into the equation, we have;
[tex] Q = 257*4.18*45[/tex]
Q = 48341.7 Joules.
Therefore, the amount of heat absorbed is 48341.7 Joules.
How do forces affect the motion of an object?
Unbalanced forces acting on an object can change that object's speed, direction or both.
Balanced forces acting on an object can change that object's speed, direction or both.
Balanced forces cause objects to accelerate.
Vectors pull objects in directions
Explanation:
Unbalanced Forces in Action
Unbalanced forces can change the motion of an object in two ways. ... Second, when unbalanced forces act on a moving object, the velocity of the object will change. Remember that a change in velocity means a change in speed, direction or both speed and direction.
What principle of fitness means that if you stop exercising your fitness level will decrease?
A.
Reversibility
B.
Overload
C.
Specificity
D.
Individuality
Answer:
A. Reversibility
Explanation:
Because if you don't progress then you do the opposite, you reverse.
Sorry if my explanation is confusing it made sense in my head i just didn't know how to put it.
hope this help. ;)
Answer:
A. Reversibility
Explanation:
please answer this question
Answer:
Pic not clear.........
A quarter is tossed up from the roof of a skyscraper and hits the sidewalk below. Which of the following graphs best shows the velocity v vv of the quarter from when it is tossed up until it reaches the ground?
Answer:
pic
Explanation:
The graph which best shows the velocity v of the quarter from when it is tossed up until it reaches the ground is attached in the answer.
What is velocity?
Velocity is the time rate of change of displacement. The displacement and velocity both are vector quantities. They represent magnitude and direction as well.
A quarter is tossed up from the roof of a skyscraper and hits the sidewalk below.
The velocity will decrease with the time linearly.
The graph which best shows the velocity v of the quarter from when it is tossed up until it reaches the ground is attached in the solution.
Learn more about velocity.
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A force of 29.4 N is required to pull a 100 kg ice block at constant speed along an ice surface. Find the coefficient of kinetic friction for ice on ice.
Answer:
The value is [tex]\mu_k = 0.03[/tex]
Explanation:
From the question we are told that
The force applied on the ice is [tex]F = 29.4 N[/tex]
The mass of the ice block is [tex]m = 100 \ kg[/tex]
Generally for the ice block to move at constant speed , the force applied on it must be equal to the kinetic frictional force which is mathematically represented as
[tex]F_F = m* g * \mu_k[/tex]
=> [tex]F = F_F = m* g * \mu_k[/tex]
=> [tex]29.4 = 100 * 9.8 * \mu_k[/tex]
=> [tex]\mu_k = 0.03[/tex]
A yo‑yo with a mass of 0.0800 kg and a rolling radius of =2.70 cm rolls down a string with a linear acceleration of 5.70 m/s2.
Calculate the tension magnitude in the string and the angular acceleration magnitude of the yo‑yo. What is the moment of inertia of this yo‑yo?
I ended up calculating the angular acceleration to be 211.11 but I'm unsure how to calculate the other parts of the problem.
Explanation:
Given that,
Mass, m = 0.08 kg
Radius of the path, r = 2.7 cm = 0.027 m
The linear acceleration of a yo-yo, a = 5.7 m/s²
We need to find the tension magnitude in the string and the angular acceleration magnitude of the yo‑yo.
(a) Tension :
The net force acting on the string is :
ma=mg-T
T=m(g-a)
Putting all the values,
T = 0.08(9.8-5.7)
= 0.328 N
(b) Angular acceleration,
The relation between the angular and linear acceleration is given by :
[tex]\alpha =\dfrac{a}{r}\\\\\alpha =\dfrac{5.7}{0.027}\\\\=211.12\ m/s^2[/tex]
(c) Moment of inertia :
The net torque acting on it is, [tex]\tau=I\alpha[/tex], I is the moment of inertia
Also, [tex]\tau=Fr[/tex]
So,
[tex]I\alpha =Fr\\\\I=\dfrac{Fr}{\alpha }\\\\I=\dfrac{0.328\times 0.027}{211.12}\\\\=4.19\times 10^{-5}\ kg-m^2[/tex]
Hence, this is the required solution.
Approximately how many Sun's are in the Milky way?
Answer:
there are uncountable sun are there but sun is star therefore there are uncountable stars are there
Answer:
1 but For many years scientists have studied our own solar system. But until the last few years, we knew of no other solar systems. This may seem surprising, as the Sun is one of about 200 billion stars (or perhaps more) just in the Milky Way galaxy alone.
Explanation:
Which particles determine the atomic number of an element?
(2 Points)
Protons only
Neutrons and protons
Neutrons only
Protons and electrons
Answer:
protons and electrons
If, instead, the mass remained the same as the original problem, but the spring was replaced by one with a spring constant that was four times as large, the period would be:__________
Answer:
T = [tex]1/2\pi \sqrt (k/m) \\[/tex] so period of mass spring system becomes 2 times w.r.t original problem.
Explanation:
[tex]T =1/2\pi \sqrt(k/m)\\[/tex] so when k = 1 is replaced by 4 it means it becomes
k" = 4k
[tex]T' = 1/2\pi \sqrt(k'/m)\\T' = 1/2\pi \sqrt(4k/m)\\T' = 2(1/2\pi\sqrt(k/m)\\)\\T' = 2T[/tex]
A 20-Kg child is on a swing attached to 3.0 m-long chains. The child swings back and forth, swinging out to a 60-degree angle. (This is the angle that the chains make with the vertical.) What is the childs maximum speed on the swing
Answer:
v = 29.4 m / s
Explanation:
For this exercise we can use the conservation of mechanical energy
Lowest starting point.
Em₀ = K = ½ m v²
final point. Higher
[tex]Em_{f}[/tex] = U = m g h
Let's use trigonometry to lock her up
cos 60 = y / L
y = L cos 60
Height is the initial length minus the length at the maximum angle
h = L - L cos 60
h = L (1- cos 60)
energy is conserved
Em₀ = Em_{f}
½ m v² = mgL (1 - cos 60)
v = 2g L (1- cos 60)
let's calculate
v² = 2 9.8 3.0 (1- cos 60)
v = 29.4 m / s
how is atmospheric and water pressure different?
Answer: Electric charges
Explanation: Atmospheric pressure isn't able to crush you because it doesn't result from weight or surface area. Atmospheric pressure, also known as weather patterns, results from escaping atmospheric gases coming together and creating electric charges. Oceanic pressure in caused from high compression of the upper layers of the water, producing thousands of tons of liquid weight crushing the bottom layer. This is how they are different forms of pressure.
A student throws a 0.1 kg dart at an angle of 20° to the horizon. Then the student changes the throwing angle. Which angle
will maximize the distance the dart will travel before it returns to its original height?
Answer:
The student must change the launch angle from 20º to 45º to maximize the horizontal distance.
Explanation:
The dart experiments a parabolical motion, which is the combination of horizontal uniform motion and vertical uniform accelerated motion due to gravity, in which effects from air friction and Earth's rotation can be neglected. The equations of motion are described below:
[tex]x = x_{o}+v_{o}\cdot t \cdot \cos \theta[/tex] (1)
[tex]y = y_{o}+v_{o}\cdot t\cdot \sin \theta +\frac{1}{2}\cdot g\cdot t^{2}[/tex] (2)
Where:
[tex]x_{o}[/tex], [tex]y_{o}[/tex] - Initial coordinates of the dart, measured in meters.
[tex]x[/tex], [tex]y[/tex] - Current coordinates of the dart, measured in meters.
[tex]v_{o}[/tex] - Initial velocity of the dart, measured in meters per second.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]t[/tex] - Time, measured in seconds.
[tex]\theta[/tex] - Launch angle, measured in sexagesimal degrees.
According to the statement, we need to determine the launch angle when [tex]\Delta x = x-x_{o} > 0[/tex], [tex]\Delta y = y-y_{o}= 0[/tex] and [tex]v_{o} > 0[/tex]. Then, we obtain the following system of linear equations:
[tex]\Delta x = v_{o}\cdot t \cdot \cos \theta[/tex] (1b)
[tex]v_{o}\cdot \sin \theta + \frac{1}{2}\cdot g \cdot t = 0[/tex] (2b)
By (2b), we clear time as follows:
[tex]t = -\frac{2\cdot v_{o}\cdot \sin \theta}{g}[/tex]
And it is applied in (1b) afterwards:
[tex]\Delta x = -\frac{2\cdot v_{o}^{2}\cdot \sin\theta \cdot \cos\theta}{g}[/tex]
[tex]\Delta x = -\frac{v_{o}^{2}\cdot \sin 2\theta}{g}[/tex] (3)
Where [tex]\Delta x[/tex] is the horizontal distance, measured in meters.
In order to determine the launch angle such that distance is maximized, we require the first and second derivatives of the function. That is:
First derivative
[tex]\Delta x' = -\frac{2\cdot v_{o}^{2}\cdot \cos 2\theta}{g}[/tex] (4)
Second derivative
[tex]\Delta x'' = \frac{2\cdot v_{o}^{2}\cdot \sin 2\theta}{g}[/tex] (5)
By equalizing (4) to zero, we find the following trigonometric equivalence:
[tex]\cos 2\theta = 0[/tex]
[tex]2\cdot \theta = 90^{\circ}[/tex]
[tex]\theta = 45^{\circ}[/tex]
A launch angle of 45º is a critical point of (3). If we know that [tex]g< 0[/tex] and [tex]\theta = 45^{\circ}[/tex] in (5), then [tex]\Delta x'' < 0[/tex], which means that critical point determined above leads to a maximum distance. Then, the student must change the launch angle from 20º to 45º to maximize the horizontal distance.
Which of the following is true if you stub (hit) your toe on a stone step?
Could we have the choices? If we have those we could help you! εїз
Which of the following is not permitted, based on the second law of
thermodynamics?
A. Heat flowing from cold to hot
B. A machine that is 80% efficient
C. Heat being completely converted into mechanical energy
D. Heat flowing from hot to cold
Answer:
A. Heat flowing from cold to hot
Explanation:
The second law of thermodynamics speaks about entropy and directions of processes. These directions go only in one direction, just as time moves only in one direction, as we know it. It is impossible to see time moving forward in a different sense. In the same way, the processes associated with heat transfer, go in a single direction this direction is associated with bodies at different temperatures. Where heat is transferred from a higher temperature body to a lower temperature body.
Heat transfer processes from a cold body to a hot body, do not exist and can not be achieved in a natural way.
Answer:
C
Explanation:
A child on roller skates undergoes as acceleration of 0.6m/s^2 due to a horizontal net force of 24N . What is the mass of the child?
Answer:
40Kg
Explanation:
F=m×a
24N÷0.6m/s^2=40
if 49 jules of work is done when a 7 newton wagon of cheeseburgers is pulled, how far does it move?
A box with a mass of 5.8 kg is lifted from the garage floor and placed on a shelf. If the box gains 145 J of
potential energy, how high is the self?
Answer:
2.27
Explanation:
Potential energy =mgh so from there u can substitute the values
A person picking apples stand on a ladder 3.0 m above the ground. He throws them into
a basket 2.0 m away. How fast must the person throw the apple in order for it to land in
the basket?
Answer:
The speed the apple must be thrown in order for it to land in the basket is 2.554 m/s.
Explanation:
Given;
height above the ground, h = 3.0 m
horizontal distance, X = 2.0 m
The time to drop from the given height;
h = ¹/₂gt²
[tex]t = \sqrt{\frac{2h}{g} }\\\\t = \sqrt{\frac{2*3}{9.8} }\\\\t = 0.783 \ s[/tex]
The horizontal speed traveled by the apple is given by;
vₓ = X / t
vₓ = 2 / 0.783
vₓ = 2.554 m/s
Therefore, the speed the apple must be thrown in order for it to land in the basket is 2.554 m/s.
1. How much work does the human heart do if it uses 180 N of force to pump blood 0.3 meters to the
lungs?
Work does the human heart do if it uses 180 N of force to pump blood 0.3 meters to the lungs 39 joule.
What is work?Work in physics is the energy that is transferred to or from an item when a force is applied along a displacement. In its simplest form, it equals the product of the force's magnitude and the distance travelled for a constant force directed in the direction of motion.
Work = force x distance. In units, Joules = Newtons x meters.
W = F.d
F = 180 N d=0.3 m
W = F.d
W = (180)(0.3)
W = 39 j
Work does the human heart do if it uses 180 N of force to pump blood 0.3 meters to the lungs 39 joule.
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what is a circit pls tell me
Answer:
A closed loop that electrons can travel in.
Explanation:
A 6.0-kg object moving at 5.0 m/s collides with and sticks to a 2.0-kg object. After the collision the composite object is moving at 2.0 m/s in a direction opposite to the initial direction of motion of the 6.0-kg object. Determine the speed of the 2.0-kg object before the collision. a. 23 m/s b. 15 m/s c. 11 m/s d. 8.0 m/s e. 7.0 m/s
Answer:
a) 23 m/s
Explanation:
Assuming no external forces acting during the collision, total momentum must be conserved, as follows:[tex]p_{o} = p_{f} (1)[/tex]
The initial momentum p₀, can be written as follows:[tex]p_{o} = m_{1} * v_{1o} + m_{2}* v_{2o} = 6.0 kg * 5.0 m/s + 2.0 kg * v_{2o} (2)[/tex]
The final momentum pf, can be written as follows:[tex]p_{f} = (m_{1} + m_{2} )* v_{f} = 8.0 kg* (-2.0 m/s) (3)[/tex]
Since (2) and (3) are equal each other, we can solve for the only unknown that remains, v₂₀, as follows:[tex]v_{2o} = \frac{-6.0kg* 5m/s -8.0 kg*2.0m/s}{2.0kg} = \frac{-46kg*m/s}{2.0kg} = -23.0 m/s (4)[/tex]
This means that the 2.0-kg object was moving at 23 m/s in a direction opposite to the 6.0-kg object, so its initial speed, before the collision, was 23.0 m/s.The speed of the 2.0-kg object before the collision will be 23 m/s.Option A is correct.
What is the law of conservation of momentum?According to the law of conservation of momentum, the momentum of the body before the collision is always equal to the momentum of the body after the collision.
The given data in the problem is;
m₁ is the mass of objthe ct = 6.0-kg
v₁ is the speed moving = 5
m₂ is the mass of object 2 = 2.0 Kg
V is the final speed = 2.0 m/s
v₂ is the speed of the 2.0-kg object before the collision =?
According to the law of conservation of momentum;
Momentum before collision =Momentum after collision
[tex]\rm m_1v_1 + m_2v_2 = V(m_1 + m_2)\\\\(6 \times 5) + (2 \times v_2) = -2.0 \times (8) \\\\ \rm v_2 = \frac{-46}{2.0} \\\\ \rm v_2 =-23.0\ m/sec[/tex]
Hence the speed of the 2.0-kg object before the collision will be 23 m/s.Option A is correct.
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How does the formation of ice in the freezing compartment of a
refrigerator demonstrate the particulate nature of matter?
A. As the particle energy of matter decreases, the motion of the atoms in a
given space decreases
B. As the particle energy of matter decreases, the motion of atoms in a given
space increases
C. As the particle energy of matter increases, the motion of atoms in a given
space decreases
D. As the particle energy of matter increases, the motion of atoms remains
unchanged
Answer:
The correct option is A
Explanation:
Generally, when the temperature of matter is low and starts to cool, the kinetic energy of it's particles decreases which causes the motion of the atoms within it's particles to also decrease. When the kinetic energy of the particles decreases, it causes the matter to form a mass by coming together since it's atoms will no longer be able to move freely as before (just like in solids) - this is the reason for the formation of ice in the freezing compartment.
From the explanation above, it can be deduced that the correct option is A
A 337 nm nitrogen laser puts out 5.00 W of power with a beam 5.90 mm in diameter. The beam is pointed directly at a pinhole which has a diameter of 1.10 mm. How many photons of light will travel through the pinhole per second? Assume that the intensity of the light is equally distributed across the whole area of the beam.
Answer:
#_foton2 = 2.96 10¹⁶ photon / s
Explanation:
We are going to solve this exercise in parts, first we will calculate how many photons are in the beam and then the amount that pass through the pinhole.
To find the energy of a photon, let's use the Planck relationship
E = h f
c = λ f
we substitute
E₀ = h c /λ
E₀ = 6.63 10⁻³⁴ 3 10⁸/337 10⁻⁹
E₀ = 5.90 10⁻¹⁹ J
Now we can use a direct ratio rule to find out the number of photons in the beam. If 1 photon has an energy E₀, how many photons are in an energy 5.00W
# _foton = 1 5/ E₀ = 1 5 / 5.90 10⁻¹⁹
#_foton = 8.5 10¹⁸ photons / s
This number of photons is uniformly distributed in the area of the circle with diameter 5.90mm = 5.90 10⁻³m
R= d/2= 2.95 10⁻³ m
r = d/2 = 0.55 10⁻³ m
let's find the beam area
A = π R²
A = π (2.95 10⁻³)²
A = 2.73 10⁻⁵ m²
the pinhole area
a = π r²
a = π (0.55 10⁻³)²
a = 9.50 10⁻⁷ m²
Let's use another direct ratio (rule of three) if there are 8.5 1018 photons / s in an area A how many photons pass through the area at
# _foton2 = 8.5 10¹⁸ a / A
# _fotn2 = 8.5 10¹⁸ 9.50 10⁻⁷ /2.73 10⁻⁵
#_foton2 = 2.96 10¹⁶ photon / s
A force of 25 newtons moves a box a distance of 4 meters in 5 seconds. The work done on the box is_ No, and the power is_Nm/s
Explanation:
workdone = force x distance
workdone= 25 x 4
workdone = 100 joules ( the unit for workdone is joules or Nm )
POWER = workdone/ time
power = 100/5
power = 20 watts ( the unit for power is watts or Nm/s )