Answer:
31.5m/s
Explanation:
Given the following
acceleration a = 4.5m/s²
Time t= 7secs
Required
Final speed v = ?
Using the equation of motion
v = u+at
v = 0+4.5(7)
v = 31.5m/s
Hence the speed of the dog is 31.5m/s
find not true when the water freezes...
Answer: i think its c
Explanation:
Answer:
a
Explanation:
Henry designs an experiment to find out why plants without flowers tend to be wind-pollinated and not animal-pollinated. He takes samples from a variety of plants and studies them in the field. He finds that the evidence supports his hypothesis. Which of these was the hypothesis Henry was testing? Choose the correct answer. Nonflowering plants make less pollen than flowering plants. Nonflowering plants lack the structures to attract animal pollinators. Nonflowering plants grow close to the ground and capture fewer pollinators. Nonflowering plants grow close to the ground because they have no pollen grains.
Answer:
option 2
Explanation:
you are very welcom
Jackson throws a football 30 meters at a speed of 15 m/s. How long was the football in the air before Laurence caught it for touchdown
Answer:
2s
Explanation:
Given parameters:
Distance = 30m
Speed = 15m/s
Unknown:
Time before Laurence caught it = ?
Solution:
To solve this problem;
Speed = [tex]\frac{disance }{time}[/tex]
Time taken = [tex]\frac{distance }{speed }[/tex] = [tex]\frac{30}{15}[/tex] = 2s
The time it takes is 2s
Given:
30 metersSpeed of 15 m/sWe will solve:
Speed = [tex]\frac{distance}{time}[/tex]
Time taken = [tex]\frac{distance}{time}[/tex] = [tex]\frac{30m}{15m/s}[/tex] = 2s
The time it takes is 2s
How high did a worker lift a 25 kg bag of sand if it now has 2940 of gravitational potential energy
Answer:
12 m
Explanation:
From the question given above, the following data were obtained:
Mass (m) of bag = 25 kg
Potential energy (PE) = 2940 J
Height (h) =?
Objects carried to a particular height will always experience an acceleration due to gravity of 9.8 m/s².
With the above in mind, we can obtain the height to which the load is lifted to as shown below:
Mass (m) of bag = 25 kg
Potential energy (PE) = 2940 J
Acceleration due to gravity (g) = 9.8 m/s².
Height (h) =?
PE = mgh
2940 = 25 × 9.8 × h
2940 = 245 × h
Divide both side by 245
h = 2940 / 245
h = 12 m
Therefore, the worker lifts the load to a height of 12 m.
A wheel of mass 50 kg has a radius of 0.4 m. It is making 480 rpm. What is the
torque necessary to bring it to rest in 40 seconds?
Solution:
Answer:
The torque necessary to bring the wheel to rest in 40 seconds is 10.4 N·m
Explanation:
The question is with regards to rotational motion
The rotary motion parameters are;
The mass of the wheel = 50 kg
The radius of the wheel = 0.4 m
The rate of rotation of the wheel = 480 rpm
The time in which the wheel is to be brought to rest = 40 s
The rotational rate of the wheel in rotation per second is given as follows;
480 r.p.m = 480 r.p.m × 1 minute/(60 seconds) = 8 revolution/second
1 revolution = 2·π radians
Therefore, we have the angular velocity, ω, given as follows;
ω = 2·π × 8 revolutions/second ≈ 50.3 rad/s
The angular acceleration, α, is given as follows;
[tex]\alpha = \dfrac{\Delta \omega}{\Delta t} = \dfrac{\omega _2 - \omega_1}{t_2 - t_1}[/tex]
Whereby the wheel is brought to rest from its initially constant rotational motion in 40 seconds, we have;
ω₁ ≈ 50.3 rad/s, ω₂ = 0 rad/s, and t₂ - t₁ = 40 seconds
Plugging in the values for the variables of the equation for the angular acceleration, "α", we get;
[tex]\alpha = \dfrac{0 - 50.3 \ rad/s}{40 \ s} \approx 1.3 \ rad/s^2[/tex]
The torque on the wheel, τ, is given as follows;
τ = m·r²·α
Where;
m = The mass of the object = 50 kg
r = The radius of the wheel = 0.4 m
α = The acceleration of the wheel ≈ 1.3 rad/s²
Therefore;
τ = 50 kg × (0.4 m)² × 1.3 rad/s² ≈ 10.4 N·m
The torque necessary to bring the wheel to rest in 40 seconds = τ ≈ 10.4 N·m.
Answer:
-10.048 N m
Explanation:
Help Please! 5 questions for 25 points? seems fair? Thank you!
Answer:
1. where the skater turns and goes back in the opposite direction- point w
2. gravitational force of the object
3. point a
4. the bar representing sphere 4 should be twice as tall as the bar representing sphere 2
5. B; its mass is smaller (?)
yolo
Answer:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Explanation:
[04.04] Which best describes the current atomic theory?
Which type of matter is likely to absorb the most sound waves? A. Metal door B. Loudspeaker C. Hot air O D. Foam wall
Answer:
its either A or D
Explanation:
They use foam walls in like asylums but in the movies all the bad guys say "They can't hear you the metal is too thick" so its either one of those, hope it helped
Sound absorbing foams are typically softer and more lightweight than their sound blocking counterparts. This open and flexible cell structure acts as a natural soundwave absorber and prevents noises from reverberating off hard surfaces like walls, floors and ceilings.
What are sound waves ?"A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords."
What is sound ?"Sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain."
What is noise ?Sound is defined as vibrations that travel through air or another medium that can be heard when they reach a person's or animal's ears. Noise is defined as unwanted sound. In engineering, noise has the additional connotation of signals varying over time without meaning, whereas sound connotes meaningful signals.
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ANSWER QUICK 30 POINTS
What force controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters? Thoroughly explain your answer, making sure to include an example and describe how this force keeps planets in orbit. Make sure to write at least 3-5 sentences and proper conventions (spelling, grammar, punctuation, etc.) to respond. Put all answers in your own words
Answer:
Gravity controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters. The Universal Law of Gravitation depends on two things. First it depends on mass of each object and the second factor is the distance between two objects. If the mass of one object is Larger, the gravitational pull towards it will be larger and the smaller distance, the larger the gravitational pull will be between the objects. Therefore the Larger planets have more moon and the inner planets have less.
Explanation:
A wave that can travel through empty space?
A. electromagnetic wave
B. mechanical wave
C. compressional wave
D. transverse wave
Answer: B. Mechanical Waves
Explanation:
You blow up a balloon but don't tie it. When you let it go, it flies around the room.
Which of Newton's Laws does the scenario describe?
1st Law
2nd Law
3rd Law
Answer:
3rd law beacuse there a flies
4. A toy car travels 60 m during 5.7 s at a constant speed. What is the speed of the toy car?
15.556
13.526
6.116
10.526
None of these is correct.
Answer: 10.526m/s
Explanation:
The speed of the toy car would be calculated as the distance travelled by the toy card divided by the time taken. This will be:
= Distance travelled / Time taken
= 60/5.7
= 10.526m/s
The speed of the toy car is 10.526 meters per second.
A student is leaving the lesson and walking to Maths at a speed of 1m/s. He notices that he is late for the lesson and speeds up to 3 m/s. It takes him 4 seconds to speed up. Calculate his acceleration.
Answer:
Acceleration = 0.5 m/s²
Explanation:
Given the following data;
Initial velocity, u = 1m/s
Final velocity, v = 3m/s
Time, t = 4 seconds
To find acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]a = \frac{v - u}{t}[/tex]
Substituting into the equation, we have;
Acceleration = (3 - 1)/4
Acceleration = 2/4
Acceleration = 0.5 m/s²
a) Las siglas M. RU significan
Answer:
Ver la explicación a continuación.
Explanation:
En física estas siglas significan movimiento rectilíneo uniforme, es decir es el tipo de movimiento donde la velocidad es constante. La velocidad no cambia con el tiempo.
Este tipo de movimiento se puede describir con la siguiente ecuación.
[tex]x=x_{0}+v*t[/tex]
Donde:
x = posición final [m]
xo = posición inicial [m]
v = velocidad [m/s]
t = tiempo [s]
A piece of glass weights 25 g in air, 16.77g in water at 4C and 16.89g in water at 60C. Find the mean coefficient of cubical expansion of water between 4C anf 60C, taking the coefficient of linear expansion of glass as 8*10^6
sorry i think so i dont exactly know i am sorry
Explanation:
As a certain amount of water is cooled from room temperature until it reaches 4 °C, its volume drops. The density reduces as the volume increases below 4 °C. Therefore, water's greatest density occurs at 4 degrees Celsius.
What coefficient of cubical expansion of water?Water has an unusual trait called anomalous expansion, which causes it to enlarge rather than compress when the temperature drops from 4 °C to 0 °C, and it becomes less dense.
At temperatures not far below zero degrees Celsius, water ice is unique for having low coefficients of static and dynamic friction that range from 0.04-0.02, but as the temperature drops, these numbers rise.
Therefore, When a metal sheet's temperature rises by one degree, its coefficient of area expansion is calculated as the increase in surface area per unit of original surface area.
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Compounds are made from the atoms of two or more______?
Answer:
elements
not really an explanation
Four velcro-lined air-hockey disks collide with each other in a perfectly
inelastic collision. The first disk has a mass of 50.0 g and a velocity of
0.80 m/s to the west, the second disk has a mass of 60.0 g and a velocity of
2.50 m/s to the north, the third disk has a mass of 100.0 g and a velocity of
0.20 m/s to the east, and the fourth disk has a mass of 40.0 g and a
velocity of 0.50 m/s to the south. What is the final velocity of the disks
after the collision?
Answer:
The magnitude of the final velocity is approximately 0.526 m/s in approximately the direction of 8.746° East of South
Explanation:
The given collision parameters are;
The kind of collision experienced by the four velcro-lined air-hockey disk = Inelastic collision
The mass of the first disk, m₁ = 50.0 g
The velocity of the first disk, v₁ = 0.80 m/s West = -0.8·i
The mass of the second disk, m₂ = 60.0 g
The velocity of the second disk, v₂ = 2.50 m/s North = 2.5·j
The mass of the third disk, m₃ = 100.0 g
The velocity of the third disk, v₃ = 0.20 m/s East = 0.20·i
The mass of the fourth disk, m₄ = 40.0 g
The velocity of the fourth disk, v₄ = 0.50 m/s South = -0.50·j
Therefore, the total initial momentum of the four velcro-lined air-hockey disk, [tex]\Sigma P_{initial}[/tex] is given as follows;
[tex]\Sigma P_{initial}[/tex] = m₁·v₁ + m₂·v₂ + m₃·v₃ + m₄·v₄ = 50.0×(-0.80·i) + 60.0×(2.50·j) + 100 × (0.20·i) + 40.0 × (-0.50·j)
∴ [tex]\Sigma P_{initial}[/tex] = -40·i + 150·j + 20·i - 20·j = -20·i + 130·j
∴ [tex]\Sigma P_{initial}[/tex] = -20·i + 130·j
By the law of conservation of linear momentum, we have;
[tex]\Sigma P_{initial} = \Sigma P _{final}[/tex] = -20·i + 130·j
Therefore, given that the collision is perfectly inelastic, the disks move as one after the collision and the four masses are added to form one mass, "m", m = m₁ + m₂ + m₃ + m₄ = 50.0 + 60.0 + 100.0 + 40.0 = 250.0
∴ m = 250.0 g
Let, "v" represent the final velocity of the four disks moving as one after the collision
We have;
[tex]\Sigma P _{final}[/tex] = m × v = 250.0 × v = -20·i + 130·j
∴ v = -20·i/250 + 130·j/250 = -0.08·i + 0.52·j
The final velocity of the four disks after collision, v = -0.08·i + 0.52·j
The magnitude of the final velocity, [tex]\left | v \right |[/tex] = √((-0.08)² + (0.52)²) ≈ 0.526
[tex]\left | v \right |[/tex] ≈ 0.526 m/s
The direction of the final velocity, θ = arctan(0.52/(-0.08)) ≈ -81.254°
The direction of the final velocity, θ ≈ -81.254° which is 8.746° East of South
Absorption of a light wave occurs in what material?
Answer: I think Windows.
Explanation: The absorption of light makes an object dark or opaque to the wavelengths or colors of the incoming wave: Wood is opaque to visible light. Some materials are opaque to some wavelengths of light, but transparent to others. Glass and water are opaque to ultraviolet light, but transparent to visible light.
Option.D-All materials is the correct answer.
Any object, whether living or inert, has the ability to absorb light. Absorption is always influenced by the electromagnetic frequency of the light being transmitted (i.e., its color) and the composition of the object's atoms.
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The diagram shows a wave traveling through a medium.
Identify point B.
amplitude
crest
trough
wavelength
The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.
What is wavelength?The distance between two successive troughs or crests is known as the wavelength.
The wavelength is also defined as the distance between two locations in a wave that have the same oscillation phase.
The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.
Hence, option B is correct.
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someone please help with this
Answer:
The new force is 2/3 of the original force
Explanation:
Coulomb's Law
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:
[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]
Where:
[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]
q1, q2 = the objects' charge
d= The distance between the objects
Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:
[tex]\displaystyle F'=k\frac{2q_1*q_2/3}{d^2}[/tex]
Factoring out 2/3:
[tex]\displaystyle F'=\frac{2}{3}k\frac{q_1*q_2}{d^2}[/tex]
Substituting the original force:
[tex]F'=\frac{2}{3}F[/tex]
The new force is 2/3 of the original force
HELP ME ASAP PLZZ
Which of the following is not a measurement taken by a radiosonde?
a. atmospheric composition
b. atmospheric pressure
c. wind speed
d. wind direction
Answer:
A atmospheric composition
A 5.0 kg chunk of putty moving at 10m/s collides and sticks to a 7.0 kg bowling ball that is initially at rest.What is the total momentum of the bowling ball and the putty after they collide?
Answer:
Total momentum = 50kgm/s
Explanation:
Given the following data;
Mass, M1 = 5kg
Mass, M2 = 7kg
Velocity, V1 = 10m/s
Velocity, V2 = 0m/s (since it's at rest).
To find the total momentum;
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
[tex] Momentum = Mass * Velocity [/tex]
The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.
Total momentum = M1V1 + M2V2
Substituting into the equation, we have;
Total momentum = 5*10 + 7*0
Total momentum = 50 + 0
Total momentum = 50 kgm/s
Therefore, the total momentum of the bowling ball and the putty after they collide is 50 kgm/s.
If a 1000 kg car is traveling at 3
meters per second, what is its
kinetic energy?