A wave passes into a different medium with an increase in speed. The ratio of the angle of incidence to the angle of refraction, defined arbitrarily here as R, is?
a) R=0
b) 1>R>0
c) R=1
d) R>1
Answer:
(d) R>1
Explanation:
Let the wave is passing from the medium [tex]M_1[/tex] to medium [tex]M_2[/tex] as shown in the figure.
Given that there is an increase in the speed in the medium [tex]M_2[/tex] , this is only due to the fact that medium
As when light passes from denser to rare medium, it moves away from the normal as shown in the figure.
So, the angle made by light rays with the normal in the rare medium, angle of refraction [tex]r[/tex], is more than the angle made by light rays with the normal in the denser medium, angle of incident [tex]i[/tex].
Hence, r>i
[tex]\Rightarrow \frac r i >1[/tex]
[tex]\Rightarrow R >1[/tex] [as r/i = R]
Hence, option (d) is correct.
in which sample of water do the water particles have more energy: 5g of ice cubes at -10 OC, or 5 g of liquid water at 20 0C? Explain
When a car turns sharply to the right, objects in the back seat move to the left. Why?
Answer:
Newtons third law of motion
Explanation:
For each action, there is an equal and opposite reaction.
A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge 235m below. If the plane is traveling horizontally with a speed of 250 km/h (69.4m/s), (a) how far in advance of the recipients ( horizontal distance) must the goods be dropped. (b) Suppose, instead that the plane release the supplies a horizontal distance of 425m in advance of the mountain climbers. What vertical velocity (up or down) should the supplies be given so that they arrive precisely at the climber's position? (c) with what speed do the supplies land in the latter case
Answer:
Explanation:
For vertical displacement of food-supply
if time taken to reach the ground be t
235 = 1/2 g t² , initial velocity downwards is zero.
t = 6.92 s
Horizontal displacement of food during this period
= 6.92 x 69.4 m
= 480.25 m .
b )
time required to cover horizontal distance of 425 m
= 425 / 69.4 = 6.124 s
This time period will be the time of vertical fall of 235 m . Let initial vertical velocity required be u
h = ut + 1/2 gt²
235 = u x 6.124 + .5 x 9.8 x 6.124²
235 = u x 6.124 + 183.76
u = 8.36 m /s
c )
v = u + gt
= 8.36 + 9.8 x 6.124
= 68.37 m /s
This will be vertical component of velocity .
horizontal velocity = 69.4 m /s
resultant velocity = √ ( 68.37² + 69.4²)
= √(4674.45 +4816.36)
= 97.42 m /s
A bicycle gear wheel is a disc with 50 ‘teeth' equally spaced around its edge, as shown. The gear wheel is rotated 10 times each second. A springy strip of metal is vibrated by the rotating ‘teeth'. The metal strip produces a sound of frequency that is equal to the frequency of vibration of the strip
Answer:
0.66mExplanation:
The question is not complete, here is the complete question, also see attached the image.
"A bicycle gear wheel is a disc with 50 ‘teeth’ equally spaced around its edge, as shown. The gear wheel is rotated 10 times each second. A springy strip of metal is vibrated by the rotating ‘teeth’. The metal strip produces a sound of frequency that is equal to the frequency of vibration of the strip. The speed of sound in air is 330ms–1. What is the wavelength of the emitted sound?"
given data
number of teeth= 50
we are told that the gear is rotated 10 times in 1 sec,
hence the frequency of the rotation past the strip is
=50*10
=500Hz
speed of sound= 330m/s
we know that
[tex]v_w = f \Lambda[/tex]-----------1
where Vw is the speed of sound,
f is its frequency, and
λ is its wavelength.
λ=Vw/f
λ=330/500
λ=0.66m
Draw a force diagram of a 23kg box of eel tails being pulled with a rope horizontally across the
bumpy floor
Answer:
Please find attached, the required force diagram of the 23 kg box of eel tails being pulled with a rope horizontally across the bumpy floor
Explanation:
The steps required to draw a force diagram includes
1) The object on which the applied forces act is identified
2) The forces acting on the object are identified by the condition or state of the object, which may be stationary or in motion
3) Specify the object on the diagram using a spot
4) Each of the forces acting on the object (the spot) are added, in vector format, showing both the magnitude and the direction of the forces
The forces acting on the box are;
a) The weight of the box, [tex]F_w[/tex], acting vertically downwards, with a magnitude given as follows;
[tex]F_w[/tex] = Mass of box × Acceleration due to gravity = 23 × 9.81 = 225.63 N
b) The force of friction, [tex]F_f[/tex], acting in the opposite direction of motion of the box, with a magnitude given as follows;
[tex]F_f[/tex] = Weight of the box × Coefficient of friction
[tex]F_f[/tex] = 225.63 N × [tex]\mu _x[/tex]
c) The force pulling the box, [tex]F_p[/tex], = The mass of the block × The acceleration of the block
The direction of the pulling force = The forward direction of motion of the box.
1. Which has more kinetic energy, a 40 kg cheetah running at 25 m/s or a 4,000 kg elephant moving at 2 m/s? How much more energy does it have?
2. At what speed would the animal with less KE have to travel to have the same kinetic energy as the animal with more KE?
3. Discuss the kinetic and potential energy of the ball on the end of a pendulum as it swings from point A to point B. Explain the kinetic energy and potential energy of the ball at each point and what happens to energy as the ball moves from point A to point B. In your discussion, answer the following questions: When is the kinetic energy of the ball zero and when is it at its highest? When is its potential energy at its lowest and at its highest? What happens to the kinetic energy and potential energy between point A and point B?
Answer:
1. The elephant has more kinetic energy at this speed and mass. It has 4,500 J more KE.
2. The elephant would have to go at a speed of 2.5 m/s to reach the same KE as the cheetah.
Explanation:
You would use the formula KE=1/2mv^2.
This formula would be filled in and completed twice, once for the elephant and once for the cheetah.
Cheetah:
KE = 1/2 (40) (25) ^2
KE = 12,500 J
Elephant:
KE = 1/2 (4,000) (2) ^2
KE = 8,000 J
This shows that the cheetah has more KE.
Then you would subtract the elephants amount of J from the cheetahs to find the difference.
Difference = 12,500 J - 8,000 J
Difference = 4,500 J
I hoped this helped with the first part :)
For the second part:
To find the speed the elephant would have to run you would fill in and complete the equation once more with different distance results.
KE = 1/2 (4,000) (2.5) ^2
KE= 12,500 J
(1) The kinetic energy of the cheetah is 12,500 J while kinetic energy of the elephant is 8,000 J
(2) The speed that the animal with lowest kinetic energy need to match up with the animal with highest kinetic energy is 2.5 m/s.
(3) At the highest point, the kinetic energy of the ball is zero while the potential energy will be maximum.
At the lowest point, the kinetic energy of the ball will be maximum while potential energy will be zero.
The kinetic of object, is the energy possessed by the object due to its motion.
The kinetic energy of the cheetah is calculated as;
K.E = ¹/₂mv²
K.E = ¹/₂ x 40 x 25²
K.E = 12,500 J
The kinetic energy of the elephant is calculated as;
K.E = ¹/₂ x 4000 x 2²
K.E = 8,000 J
(2) The speed of the animal with less kinetic energy to match up with the animal with higher kinetic energy;
12,500 = ¹/₂ x 4000 x v²
25,000 = 4000v²
[tex]v^2 = \frac{25,000}{4000} \\\\v^2 = 6.25\\\\v= \sqrt{6.25} \\\\v = 2.5 \ m/s[/tex]
(3) In a simple pendulum motion, point A (initial position) is the lowest point while point B (final position) is the highest point in the motion path.
At the highest point, the velocity of the ball is zero and the ball will have zero kinetic energy while the potential energy which increases with height will be maximum.
At the lowest point, the velocity of the ball will be maximum and the ball will have maximum kinetic energy while potential energy will be zero since the height is zero.
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7. Which of the following best describes Philippine regional literature?
Explanation:
where is the option of the Question
The second is a flexible _________.
Answer:
static stretching
Explanation:
hope this helped ^^
What variable/s can you manipulate in the simulation to make all the items get the same proximate values for their
acceleration? Explain how this idea will work.
Answer:
Please find the answer in the explanation.
Explanation:
The variable/s you can manipulate in the simulation to make all the items get the same proximate values for their acceleration will be the variable final velocity. Since all of them have zero initial velocity, the acceleration will tend to zero if they have a constant velocity.
If the final velocity is also zero or approximately equal to zero, that means the velocity is constant. And whenever there is constant velocity, the acceleration will be equal to zero.
Also, if the final velocity of all the parameters are very closed, they will surely have approximately same acceleration.
The variable which can be manipulated in the simulation will be the final
velocity.
The table shows all of them having the same initial velocity which is zero,
then the final velocity will have to be varied in order to get the same
proximate values for their acceleration.
Acceleration is the rate of change of velocity with time and when the velocity
is constant or equal to zero, the acceleration will be equal to zero.If the final
velocity of all the parameters are very close in value , then they will have
proximate values for acceleration.
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How far(in meters) will you travel in 3 minutes running at a rate of 6 m/s
Answer:
1080 meters is the answer
In one half hour, a car traveled 35km. What was the speed of the car?
Answer:
70km/h
Explanation:
speed = distance /time
= 35/0.5
=70km/h
A 45,000-kg airplane experiences a force from its engines of 110,000 N. What is the acceleration of the airplane?
A.0.41 m/s^2
B.0.82 m/s^2
C.2.4 m/s^2
D.9.8 m/s^2
Answer:
The answer is option CExplanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{110000}{45000} = \frac{110}{45} = \frac{22}{9} \\ = 2.4444444...[/tex]
We have the final answer as
2.4 m/s²Hope this helps you
A plane has a speed of 285 km/h west relative to the air. A wind blows 25 km/h east relative to the ground. what are the planes speed and direction relative to the ground?
Answer:
260 km/h
Explanation:
Motion is said to be relative when the motion observed by the observer depends on the location (frame) of the observer.
When two objects are moving in opposite directions, the relative motion is obtained by subtraction.
Hence the plane is moving at (285 - 25) km/h giving 260 km/h
If Phred throws a rock straight up, and Phran throws a rock straight up with twice the velocity of Pread's rock, how will the maximum height of Phred's rock compare to Phran's?
Answer:
The maximum height of Phran stone is four time that of Phred stone
Explanation:
From the question we are told that
The initial velocity of Phred stone is u
The initial velocity of Phran stone is 2u
Generally from kinematic equations
[tex]v^2 = u^2 + 2(-g)h[/tex]
Here the negative sign shows that the direction of the stone is against gravity
At the maximum height v which is the final velocity of the stone is zero
So
[tex]0 = u^2 - 2gh[/tex]
So for Phred stone the height attained is
=> [tex]h_1 = \frac{u^2}{2g}[/tex]
For Phran stone the height attained is
=> [tex]h_2 = \frac{(2u)^2}{2g}[/tex]
=> [tex]h_2 = \frac{4u^2}{2g}[/tex]
=> [tex]h_2 = 4 h_1[/tex]
Hence the maximum height of Phran stone is four time that of Phred stone
Which pair correctly identifies the strongest and weakest fundamental forces,
with the strongest force listed first?
O A. Strong nuclear force
Weak nuclear force
B. Strong nuclear force
Gravity
O C. Electromagnetic force
Strong nuclear force
D. Gravity
Strong nuclear force
Answer: Option B.
Strong nuclear force Gravity.
Explanation:
Nuclear force is the strongest force while Gravity is the weakest force. Strong nuclear force is the strongest force because it's act and hold atoms of matter together. It also binds neutrons and protons together to form atomic nuclei and it's has strength of 1.
Gravity is considered the weak force out of the four fundamental forces because it has a very small strength of 10^40 than electromagnetic force.
What is an example of Newton's First Law of Motion?
used for measurement of physical quantity is called the unit of that
quantity
Answer:
Unit
Explanation:
The reference standard used for the measurement of physical quantity is called the unit of that quantity.
Most units follow an agreed system of expressing quantities across all instances of such quantity.
It is necessary to standardized units because it makes comparison easier. It also makes scientific communication easily discernible.How do mechanical waves travel through a medium?
Answer:
sound waves need to travel through a medium such as solids,liquids and gases. hoped this helped
Explanation:
sound waves
Select the correct answer. An object has one force acting on it. It is a 33-newton force pointing downward. To create a net force of zero on the object, which force must be applied to it? Group of answer choices a 1-newton force pointing right a 0-newton force pointing downward a 33-newton force pointing upward a 33-newton force pointing left a 1-newton force pointing upward
Answer:
33 Newton upwards to get a net force of zero.
Answer:
The answer is 33 newtons with a net force of 0
Explanation:
please help me!!!
A pigeon is walking around the courtyard looking for food the pigeon walks 4.0 m West 2.5 M North 1.1 M and 7.3 m south what is the pigeons final displacement vector
Answer: ARE YOU DOING PRIMAVERA?!? PLEASE I KNOW YOU ARE I CANT DO PHYSICS-
Explanation:
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The pigeon final position displacement vector represented as , [tex]-2.9i-4.8j[/tex]
Given that Pigeon walks 4.0 m West then 2.5 m North then 1.1 m east and then 7.3 m south.
A diagram is attached below which describe the above situation.
In attached diagram, Distance DO represent the displacement.
From Diagram, it is observed that final position D of Pigeon is 4.8 m away from x axis and 2.9 m away from y axis.
Thus, Displacement vector represented as , [tex]-2.9i-4.8j[/tex]
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The air contained water that froze at 0 °C
The change in internal energy of the water as it froze was 0.70 kJ The specific latent heat of fusion of water is 330 kJ/kg
Calculate the mass of ice produced.
Answer:
The mass of the ice produced is approximately 0.00212 kg
Explanation:
The given parameters are;
The temperature at which the air changed from water to ice = 0°C
The internal energy change of the water as it froze = 0.7 kJ
The specific latent heat of fusion of water = 330 kJ/kg
Given that the change in internal energy causes the water to change state, from the principle of energy conservation, we have;
The latent heat of fusion = The change in internal energy of the water as it froze
∴ The latent heat of fusion [tex]\Delta H^{\circ}_{fus}[/tex] = 0.70 kJ
The formula for the latent heat of fusion, [tex]\Delta H^{\circ}_{fus}[/tex] = Mass × The specific latent heat of fusion, [tex]L^{\circ}_f[/tex]
Therefore, for the water, we have;
0.7 kJ = m × 330 kJ/kg
m = 0.7 kJ/(330 kJ/kg) ≈ 0.00212 kg
The mass, m, of the ice produced ≈ 0.00212 kg.
6. An elephant is putting 25,000 newtons of force on Leah. The elephant
is accelerating at a rate of 10 mIs? what is its mass?
pls don't answer if you don't know the answer.
does anyone know how to do the Student Exploration: Longitudinal Waves on Gizmos worksheet.
I don't understand it.
Answer:
Search it
Explanation:
its on it
THE ONE WHO WILL ANSWER IT CORRECT WILL BE MARKED AS "BRAINLIST"....... If the radius of the orbit of a spaceship from the centre of the earth is twice the radius of the earth . then calculate the acceleration due to the gravity on space ship.
Answer:
Explanation:
19116 being the distance from the centre of the earth to the point you want to check in metres. So after all that you get G = 1.0888m/second squared. Hope that helps you/ you should be able to pop in any height you want.
plz mark as brainliest
If you stood on mars and lifted a 15kg pack, you would be pulling with a force greater than...?
Pls i need help and I will give brainliest to the best explained answer :)
Answer:
See the answers below
Explanation:
In this problem, we must be clear about the concept of weight. Weight is defined as the product of mass by gravitational acceleration.
We must be clear that the mass is always preserved, that is, the mass of 15 [kg] will always be the same regardless of the planet where they are.
[tex]W=m*g[/tex]
where:
W = weight [N] (units of Newtons)
m = mass = 15 [kg]
g = gravity acceleration [m/s²]
Since we have 9 places with different gravitational acceleration, then we calculate the weight in each of these nine places.
Mercury
[tex]w_{mercury} = 15*3.8\\w_{mercury}= 57 [N]\\[/tex]
Venus
[tex]w_{venus}=15*8.8\\w_{venus}= 132 [N][/tex]
Moon
[tex]w_{moon}=15*1.6\\w_{moon}=24[N][/tex]
Mars
[tex]w_{mars}=15*3.7\\w_{mars}=55.5 [N][/tex]
Jupiter
[tex]w_{jupiter}=15*23.1\\w_{jupiter}= 346.5[N][/tex]
Saturn
[tex]w_{saturn}=15*9\\w_{saturn}=135[N][/tex]
Uranus
[tex]w_{uranus}=15*8.7\\w_{uranus}=130.5[N][/tex]
Neptune
[tex]w_{neptune}=15*11\\w_{neptune}=165[N][/tex]
Pluto
[tex]w_{pluto}=15*0.6\\w_{pluto}=9[N][/tex]
Coincidence?
stu(died)
stu(dying)
stu(dies)
five difference between elastic collision and inelastic collision?
Answer:
Elastic Collision
Inelastic Collision
The total kinetic energy is conserved. The total kinetic energy of the bodies at the beginning and the end of the collision is different.
Momentum does not change. Momentum changes.
No conversion of energy takes place. Kinetic energy is changed into other energy such as sound or heat energy.
Highly unlikely in the real world as there is almost always a change in energy. This is the normal form of collision in the real world.
An example of this can be swinging balls or a spacecraft flying near a planet but not getting affected by its gravity in the end.
NEED HELP ASAP, WILL GIVE BRAINLIEST
Which is an example of convection currents?
marshmallows toasting over a campfire
a pot being heated by an electric burner
feet getting hot when stepping across sand
a radiator emitting warm air and drawing in cool air
Answer:
D-A radiator emitting warm air and drawing in cool air
Explanation:
Which of the following is the equation for calculating daily caloric needs? A. BMR calories + Digestion calories B. BMR calories + Activity Level calories + Digestion calories C. BMI + Activity Level calories D. Activity Level calories + Digestion Calories
Explanation:
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows: If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2. If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375.
HAPPY TO HELP
Energy is measured in form of calories.
What is energy?Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:
If you are sedentary (little or no exercise) :
Calorie-Calculation = BMR x 1.2.
If you are lightly active (light exercise/sports 1-3 days/week) :
Calorie-Calculation = BMR x 1.375
Energy is measured in form of calories.
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