Answer:
7.53 km
Explanation:
We at given;
Speed of runner; v_r = 8.5 km/hr
Speed of bird; v_y = 17 km/hr
L = 6.4 km
We know that; time = distance/speed.
We are told that the bird starts from 6.4 km from the start and that it flies back to meet the runner after it reaches the finish line. If the total distance back to the runner is x, it means bird distance is 6.4 + (6.4 - x) = 12.8 - x
Thus;
Time of bird(t_y) = (12.8 - x)/17
Thus,
Time of runner(t_r) = x/8.5 hr
To find x, we have to equate the times of the runner and the bird.
Thus;
x/8.5 = (12.8 - x)/17
Multiply both sides by 17 to get;
2x = 12.8 - x
2x + x = 12.8
3x = 12.8
x = 12.8/3
x = 4.27 km
Thus, cumulative distance traveled by bird is; 12.8 - 4.27 = 7.53 km
If the velocity of an object is zero, then that object cannot be accelerating. | True or False
Answer: False
Explanation:
.
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6. find the focal length of alens of power
-2.0D. what type of lens is this?
Answer:
[tex]-\frac{1}{2}[/tex]
Diverging lens
Explanation:
Given parameters:
Power of lens = -2.0D
Unknown:
Focal length = ?
Solution:
The power of lens is the reciprocal of the focal length;
P = [tex]\frac{1}{f}[/tex]
where f is the focal length
f = [tex]\frac{1}{P}[/tex] = [tex]-\frac{1}{2}[/tex]
The lens is a diverging lens
A rocket is launched from the origin with an acceleration of 20.0 m/s2 in a straight line at an angle of 30.0 degrees above the horizontal. The launch acceleration lasts for 2.00 seconds at which time the fuel is exhausted. The rocket then falls with an acceleration of 9.80 m/s2 downward. What is the time it takes to reach maximum height?
Answer:
4.04 seconds
Explanation:
Context before solving:In order to solve this problem, we must keep in mind that the initial 2.00 seconds at which the fuel is exhausted does not signal when the rocket reaches its maximum height.
From this moment on, the rocket has a downward acceleration of 9.8 m/s² but it still has an upwards velocity, which we will calculate. This upwards velocity keeps the rocket moving up for a certain period of time, which we will also calculate.
For this problem, let's set the upwards direction to be positive and the downwards direction to be negative.
To find the time that the rocket takes to reach its maximum height, we are going to use the initial 2.00 seconds and find the additional seconds it takes to reach a final vertical velocity of 0 m/s. This represents the time at which the rocket stops moving and heads in the downwards direction, which takes place after the rocket has reached its maximum height.
Solving for initial velocity:The time in the air of an object in projectile motion can be found using this equation, derived from one of the constant acceleration kinematic equations.
Time in the air (projectile motion):
[tex]$t=\frac{2v_isin\theta}{g}[/tex] where g = gravitation acceleration = 9.8 m/s²Solve for [tex]v_i[/tex] by plugging in 2.00 seconds for t, 30 degrees for theta, and 20.0 m/s² for acceleration, since this is not a constant acceleration problem.
[tex]$2.00=\frac{2v_isin(30)}{20.0}[/tex]Multiply sin(30) and 2 together.
[tex]$2=\frac{v_i}{20}[/tex]Multiply 20 to both sides of the equation.
[tex]$40=v_i[/tex] [tex]v_i=40[/tex]Finding the vertical component:Now we know that the initial velocity of the rocket is 40 m/s. We need to solve for the vertical component of the rocket's velocity in order to solve for the additional time it took after the 2.00 seconds to reach its maximum height.
Vertical component:
[tex](v_i)_y=v_i \times sin\theta[/tex] [tex](v_i)_y=(40) \times sin(30)[/tex][tex](v_i)_y=20[/tex]The vertical component of the velocity vector is 20 m/s.
Finding additional seconds after 2.00 s:Now, in order to solve for the additional seconds that the rocket took to reach its maximum height, let's use one of the kinematic constant acceleration equations that uses the variables [tex]v_f[/tex], [tex]v_i[/tex], [tex]a[/tex], and [tex]t[/tex].
[tex]v_f=v_i + at[/tex]Since we are trying to solve for time, we need to use this equation in terms of the vertical direction, aka the y-direction. Time is the same in either case.
[tex](v_f)_y=(v_i)_y+a_yt[/tex]The final vertical velocity of this rocket is 0 m/s at the top, or its maximum height. We found that the vertical component, aka the rocket's initial vertical velocity, is 20 m/s. The acceleration is given to us: -9.8 m/s² (since it's falling downwards, the acceleration must be negative because we already established this in the beginning).
We are trying to solve for time t. Substitute the known values into the equation.
[tex]0=(20)+(-9.8)t[/tex]Subtract 20 from both sides of the equation.
[tex]-20=-9.8t[/tex]Divide both sides of the equation by -9.8.
[tex]2.040816327=t[/tex] [tex]t=2.04\ \text{seconds}[/tex] Finding total time to reach max height:Now we can take this time and add it to the initial 2.00 seconds of the rocket. This time we just solved for is the time after these initial seconds that the rocket kept going upwards, since its initial vertical velocity was not 0 m/s yet.
[tex]2.00+2.04=4.04 \ \text{seconds}[/tex]The time that the rocket takes to reach its maximum height is 4.04 seconds.
Answer:
4.04 second is your answer hope it help you........
A roller coaster is travelling 1 m/s at the top of the track. At the bottom of the track, 5 seconds later, it is travelling 36 m/s. What is the average acceleration?
7.2 m/s2
0.14 m/s2
36 m/s 2
7 m/s2
Answer:
7m/s²
Explanation:
Given parameters:
Velocity at the top = 1m/s
Velocity at the bottom = 36m/s
Time = 5s
Unknown:
Average acceleration = ?
Solution;
Acceleration is the rate of change of velocity with time. It is expressed as;
A = [tex]\frac{v -u}{t}[/tex]
v is the velocity at the top
u is the velocity at the bottom
t is the time taken
Now, insert the parameters and solve;
A = [tex]\frac{36 - 1}{5}[/tex] = 7m/s²
Given values:
Top velocity,
v = 1 m/sBottom velocity,
u = 36 m/sTime,
t = 5 sThe acceleration is:
→ [tex]A = \frac{v -u}{t}[/tex]
By putting the values,
[tex]= \frac{36-1}{5}[/tex]
[tex]= \frac{35}{5}[/tex]
[tex]= 7 \ m/s^2[/tex]
Thus the answer above i.e., "option d" is correct.
Learn more about acceleration here:
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Which statement accurately describes planetesimals?
A. They are the origins of planets.
B. They formed from ice and rocks.
C. They were created during the big bang.
D. They contain 98% of matter in the solar system
Answer:
B
Explanation:
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3. The soccer kicker kicks a 2 kg football with a force of 68 N. How fast will the ball accelerate down the field?
m = _______
a = ________
Fnet = _____
Answer:
[tex]\boxed {\boxed {\sf m= 2 \ kg , \\a= 34 \ m/s^2, \\\F= 68 \ N}}[/tex]
Explanation:
The formula for force is:
[tex]F=m*a[/tex]
If we rearrange the formula to solve for a (acceleration), the formula becomes
[tex]\frac{F}{m} =a[/tex]
The force is 68 Newtons. Let's convert the units to make the problem easier later on. 1 N is equal to 1 kg*m/s², so the force of 68 N is equal to 68 kg*m/s².
The mass is 2 kilograms.
[tex]F=68 \ kg*m/s^2 \\m= 2\ kg[/tex]
Substitute the values into the formula.
[tex]\frac{68 \ kg*m/s^2}{2 \ kg} =a[/tex]
Divide. Note that the kilograms will cancel each other out (hence why we changed the units).
[tex]\frac{68 \ m/s^2}{2}=a[/tex]
[tex]34 \ m/s^2=a[/tex]
The acceleration is 34 meters per second squared.
Can some smart person help me out here!!!!!!!
Answer:
B
Explanation:
when you put it on a smooth surface and they're both at the same level it'll determine which one is faster and which one has less Mass. hope this helps much love .
There are no smart people available at the moment, but I'll try and help you.
Do the SECOND choice on the list. Keep the forces of the push on both blocks exactly equal. The block that jumps out ahead has less mass. The block that lags behind has more mass.
A student determines the density ρ of steel by taking measurements from a steel wire
Mass- 6.2 +-0.1g
Length- 25.0 +-0.1m
Diameter- 2.00 +-0.01mm
He uses the equation ρ= 4m/πd^2l
What is the percentage uncertainty in his calculated value of density ?
Answer:
The percentage uncertainty in his calculated value of density is [tex]\pm 0.713\,\%[/tex].
Explanation:
We can estimate the absolute uncertainty by the definition of total differential. That is:
[tex]\Delta \rho \approx \frac{\partial \rho}{\partial m}\cdot \Delta m + \frac{\partial \rho}{\partial d}\cdot \Delta d + \frac{\partial \rho}{\partial l}\cdot \Delta l[/tex] (1)
Where:
[tex]\frac{\partial \rho}{\partial m}[/tex] - Partial derivative of the density with respect to mass, measured in [tex]\frac{1}{mm^{3}}[/tex].
[tex]\frac{\partial \rho}{\partial d}[/tex] - Partial derivative of the density with respect to diameter, measured in grams per cubic milimeter.
[tex]\frac{\partial \rho}{\partial l}[/tex] - Partial derivative of the density with respect to length, measured in grams per cubic milimeter.
[tex]\Delta m[/tex] - Mass uncertainty, measured in grams.
[tex]\Delta d[/tex] - Diameter uncertainty, measured in milimeters.
[tex]\Delta l[/tex] - Length uncertainty, measured in milimeters.
[tex]\Delta \rho[/tex] - Density uncertainty, measured in grams per cubic milimeters.
Partial derivatives are, respectively:
[tex]\frac{\partial \rho}{\partial m} = \frac{4}{\pi\cdot d^{2}\cdot l}[/tex] (2)
[tex]\frac{\partial \rho}{\partial d} = -\frac{8\cdot m}{\pi\cdot d^{3}\cdot l}[/tex] (3)
[tex]\frac{\partial \rho}{\partial l} = - \frac{4\cdot m}{\pi\cdot d^{2}\cdot l^{2}}[/tex] (4)
And we expand (1) as follows:
[tex]\Delta \rho \approx \frac{4\cdot \Delta m}{\pi\cdot d^{2}\cdot l} - \frac{8\cdot m\cdot \Delta d}{\pi\cdot d^{3}\cdot l}-\frac{4\cdot m\cdot \Delta l}{\pi\cdot d^{2}\cdot l^{2}}[/tex]
[tex]\Delta \rho \approx \left(\frac{4}{\pi\cdot d^{2}\cdot l}\right)\cdot \left(\Delta m -\frac{m\cdot \Delta d}{d}-\frac{m \cdot \Delta l}{l} \right)[/tex] (5)
If we know that [tex]d = 2\,mm[/tex], [tex]l = 25\,mm[/tex], [tex]m = 6.2\,g[/tex], [tex]\Delta m = \pm 0.1\,g[/tex], [tex]\Delta d = \pm 0.01\,mm[/tex] and [tex]\Delta l = \pm 0.1\,mm[/tex], then the absolute uncertainty is:
[tex]\Delta \rho \approx \pm\left[\frac{4}{\pi\cdot (2\,mm)^{2}\cdot (25\,mm)} \right]\cdot \left[(0.1\,g)-\frac{(6.2\,g)\cdot (0.01\,mm)}{2\,mm} -\frac{(6.2\,g)\cdot (0.1\,mm)}{25\,mm} \right][/tex]
[tex]\Delta \rho \approx \pm 5.628\times 10^{-4}\,\frac{g}{mm^{3}}[/tex]
And the expected density is:
[tex]\rho = \frac{4\cdot m}{\pi\cdot d^{2}\cdot l}[/tex] (6)
[tex]\rho = \frac{4\cdot (6.2\,g)}{\pi\cdot (2\,mm)^{2}\cdot (25\,mm)}[/tex]
[tex]\rho \approx 78.941\times 10^{-3}\,\frac{g}{mm^{3}}[/tex]
The percentage uncertainty in his calculated value of density is:
[tex]\%e = \frac{\Delta \rho}{\rho}\times 100\,\%[/tex] (7)
If we know that [tex]\Delta \rho \approx \pm 5.628\times 10^{-4}\,\frac{g}{mm^{3}}[/tex] and [tex]\rho \approx 78.941\times 10^{-3}\,\frac{g}{mm^{3}}[/tex], then the percentage uncertainty is:
[tex]\%e = \frac{\pm 5.628\times 10^{-4}\,\frac{g}{mm^{3}} }{78.941\times 10^{-3}\,\frac{g}{mm^{3}} }\times 100\,\%[/tex]
[tex]\%e = \pm 0.713\,\%[/tex]
The percentage uncertainty in his calculated value of density is [tex]\pm 0.713\,\%[/tex].
What two factors are a part of thermohaline circulation
Answer:
These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation.
Explanation:
How far will you travel in 3.5 hrs if you have an average velocity of 90 km/hr
Answer:
The answer is 315 km
a man climbs a ladder.which quamtities can be used to calculatethe useful power of the man
Explanation:
Power is the rate at which work is done. It is expressed as:
Power = [tex]\frac{work done}{time taken}[/tex]
To find the power of the man climbing the ladder, we must know the work he is doing and the duration of the work done.
Work done = force x distance
Since he climbs,
Force = weight = mg (mass x acceleration due to gravity)
distance = height = h
Power = [tex]\frac{mgh}{t}[/tex]
t is the time
If we know these parameters, we can find the power.
which is one characteristic of an electron?
Answer:
The electron is a negatively charged particle found in the atoms of all the elements. The electrons are located outside the nucleus in an atom. An electron is usually represented by the symbol (e –). The mass of an electron is about the mass of a hydrogen atom.
Explanation:
You walk forward 105 meters, in 15 seconds. What is your overall velocity? I need help immediately please
Explain why both a power source (like a battery) and a complete circuit are necessary for an electromagnet to function.
Answer: So that it can function.
Explanation:
Define Gulf in your own words?
Which of these is an example of heat transfer by conduction?
cooking carrots in hot water
drying hair with a blow dryer
pressing a shirt with an iron
warming water with sunlight
Answer:
pressing a shirt with an iron
Explanation:
Heat transfer by conduction is when heat is transferred by two objects in contact with each other.
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20 points HELP‼️ Which is more important in developing who
you are-environment or genetics? Explain why you believe this.
Answer:
Environment
Explanation:
Your Environment, More Than Genetics, Determines Your Immune Health. When it comes to immunity, the environment you grow up in, or how you were 'nurtured' , is more important than nature, a new study suggests. Particularly as you get older.
based on your reading "take a closer look" what can you say about the image that forms on the retina of your eye?
Answer:
it is an upside-down image but the brain realizes it and corrects it in its orientation so we see it in right direction.
Answer:
The lens of the eye is a convex lens. The image that it forms on the retina is upside down.
Explanation:
The eye makes an image, but it is upside down, the brain corrects the image and turns it right side up
ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements.
In working this problem, assume the value of "g" to be 9.8 m/s2 with two (2) significant digits unless otherwise stated.
A machine exerts a 100 N force to the right over a 5.00 meter length in 4.00 seconds. Calculate the power output of this machine.
_____ W
500.
125
80.0
0.200
Answer:
The answer is 500
Explanation:
what did taking measurements reveal about the velocity of the fireball? Was the fireball’s velocity constant or changing?
Answer:
The fireball slows down when moving upward. It speeds up when moving downward. So, its velocity is always changing.
Answer:
The fireball went in the air and slowed down. This is because, the gravity holds us down on earth and if not, we would be floating everywhere. So, the fireball slows down because the gravity is pulling it back down. As well as it's going down, it becomes faster. Just like when we jump, we come down pretty fast. So, when the gravity pulls you down and you go down it starts to pick up speed. Thats just how gravity works.
Explanation:
I put this in my own words.
I hope this helps anyone that needs it! :)
Please help I need this right now
Answer:
The basket ball
Explanation:
The heavier an object is the more kinetic energy it will have even if it is thrown at the same speed; therefore, since the basketball is the heaviest, it is the logical answer.
While a marble is heavy for its size, it would not have the same kinetic energy as the basket ball.
Beach balls weigh the least out of the options given so this cannot be the answer.
Golf balls, while they are dense, they do not weigh nearly as much as a basketball would!
Hope this helps <3
Answer:
The answer is B the basketball
Explanation:
Which of the following statements is correct.
A. A direct relationship exists between frequency and wavelength, as the frequency increase from Radio waves to Gamma rays so does the wavelength.
B. A direct relationship exists between frequency and wavelength, as the frequency decrease
from Radio waves to Gamma rays so does the wavelength.
C. An indirect relationship exists between frequency and wavelength, as the frequency increase
from Radio waves to Gamma rays the wavelength decrease.
D. An indirect relationship exists between frequency and wavelength, as the frequency decrease
from Radio waves to Gamma rays Wie wavelength increase
gravitational forces is ------ force
Answer:
Gravitational force is noncontact force
Explanation:
Contact force occurs due to the contact between two different objects. Non-contact force occurs due to either attraction or repulsion between two objects such that there is no contact between these objects. There is no field linked with the contact force. ... Gravitational force is an example of a non-contact force.
If you committed a crime, would it be easy for investigators to match this print to your records? Why or why not? Hint: how’s the quality of the lifted print? How rare is your pattern? (At least two sentences)
Answer:
This question is incomplete
Explanation:
This question is incomplete because of the absence of the picture of the print in question. However, when the quality of the print obtained from a crime scene is high/good, then this is a good/positive step in identification of a suspect. However, if the quality is bad, other options might need to be explored in addendum to the print obtained in identifying a suspect.
If the quality of the print is good enough to make a pattern, then another factor comes into play. If the pattern is a rare pattern or is not common, then it becomes easier to identify the suspect because there would be fewer people having that fingerprint and fewer people to deal with. Of the three major patterns of fingerprints (whorl, loop and arch), arch fingerprints are the least common.
Answer if you know
If you give me a good explanation on how quantum mechanics work, you get 20 points and possibly a brainliest.
Answer:
spectra.
Atomic spectra is series of colored lines which occures when atoms emit light of certain wavelengths. Element produces a particular set of spectral lines.
Electrons exist in shells and each shell has a specific energy. Electrons absorb photons and jump to higher energy levels.
Explanation:
2. An object is moving with an initial velocity of 12 m/s. It accelerates at a rate of 1.5 m/s^2 over a distance of 40 m. What is its new velocity?
Answer:
16.2 m/s
Explanation:
2ad=Vf^2-Vi^2
2 (1.5) (40) = Vf^2 -(12)^2
Vf= 16.2 m/s
What is temperature? Using the example of the pot of boiling water, describe how you think temperature is related to thermal energy.
Answer:
An example would be "The soup is boiling hot and has a temperature of 100 °C, whereas the water in the tub is just comfortably warm, with a temperature of about 38 °C. Although the water in the tub has a much lower temperature, it has greater thermal energy".
Explanation:
Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter.
What current flows through a bulb if 360 C of charge moves through
a bulb in 20 minutes?
Answer: A current of 1 A is flowing in a circuit if a charge of 1 coulomb passes any point in the circuit every second.
1 Amp = 1 Coulomb per second
We can write this formula as:
Current (I) = Charge (Q) / Time (t)
Charge (Q) = Current (I) x Time (t)
Explanation:
Please identify the type of inference happening at letter A and the type of interference happening at letter B. If this was a sound wave, which (A or B) do you think would be louder and why?
Answer:
B i think
Explanation:
B because it travels in the same wavelentgh.............
[tex]gjkrejktg[/tex]
Type A is constructive interference and Type B wave gives destructive interference. The constructive interference would be louder.
What is interfernece?Interference can be described as a natural phenomenon that occurs at every place and at every moment. Interference can be defined as the phenomenon in which two waves superpose to produce the resultant wave of the lower, higher, or same amplitude. Light waves are produced randomly by most of the sources.
The interference of light from the soap bubble which reflects colors when illuminated by a light source. The starting point of the wave produced may be a maximum or a minimum, and there is no way to predict which phase the wave will start.
Interference can either be constructive interference or destructive interference. Constructive interference occurs when the crest of one wave falls on the crest of another wave and the amplitude is maximum.
In destructive interference, when the crest of one wave falls on the trough of another wave and the amplitude is minimum. The phase and displacement of these waves are not the same.
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