Answer:
The correct answer is the third option
Explanation:
To reflect means to bounce off. When an incoming ray (called incident ray) gets to a boundary and bounces off the boundary, that is referred to as reflection. However, when an incident ray passes through the boundary and it causes a change in the direction of propagation of the wave, that is referred to as refraction. Thus, the correct option, as explained above, is; In reflection, rays bounce off a boundary, and in refraction, rays pass through a boundary.
Answer:
c
Explanation:
on edge 2020
Hi can you help me with this please?
An eagle , initially at rest on the ground , lifts off vertically with a constant acceleration of 25 meters per square second . How long will it take the eagle to reach an altitude of 100 meters ?
Answer:
4s
Explanation:
My assumption would be 4s since 25 going into 100 would be 4? hope that helped..
If a net force of 375N is acting on a crate and there is 65N of friction
created, what is the magnitude net force the crate experiences?
375N
65N
310N
440N
Answer:
310 N
Explanation:
The net force, I assume, is an applied force that is causing motion of the crate. However, frictional force opposes this motion, so the frictional force is in the opposite direction. Overall, we can create a net force equation of this crate as
Fnet= Force applied + Force of friction
Thus,
Fnet= 375N -65N (because friction is in the opposite direction)
Then solve to get that the net force while the crate is in motion is 310N.
1
Suppose you ride a bicycle around the block, returning to your starting point.
At the end of your trip, your average velocity will be ..........
Positive
Negative
Zero
Answer:
zero
Explanation:
this is the answer
the kinetic energy of an object of mass in moving with a velocity of 5 MS -1 is 25j what will be its kinetic energy when its velocity is doubled what will be its kinetic energy when its velocity is increased three times. please answer fast I will mark brainly
Answer:
When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J
Explanation:
Kinetic Energy
Is the type of energy an object has due to its speed. It's proportional to the square of the speed.
The equation for the kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]
Where:
m = mass of the object
v = speed at which the object moves
The kinetic energy is expressed in Joules (J)
The object has a kinetic energy of K=25 J when moving at v=5 m/s, thus the mass can be calculated by solving for m:
[tex]\displaystyle m=\frac{2K}{v^2}[/tex]
[tex]\displaystyle m=\frac{2*25}{5^2}=2[/tex]
m = 2 Kg
If the speed is doubled, v=10 m/s, the new kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}2\cdot 10^2[/tex]
K = 100 J
If the speed is tripled, v=15 m/s, the new kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}2\cdot 15^2[/tex]
K = 225 J
When the speed is doubled, K = 100 J, when the speed is tripled, K = 225 J
please answer it fast and correctly
Answer:
(1) chess is played by him
(2) The great black engine was seen by her
(3) Arrangements for functions had been made by him
(4) A meeting is being attended by Raman
= when the last of the guests left, I went back into the hall to look for my mobile phone that I had kept on the table, I found that my mobile phone was not there. I felt freaked and I asked to every member of my family about my phone, but nobody had idea about that. then there was a phone call made by my uncle to my father, that his son had taken the mobile by mistake. After sometime, My uncle came to return my mobile. Then I took a sigh of relief .
please mark me as a brainelist
The vocal cords in your throat _____________.
collapse
vibrate
compress
Answer:
vibrate
Explanation:
Vocal folds vibrate when excited by aerodynamic phenomena; they are not plucked like a guitar string. Air pressure from the lungs controls the open phase. The passing air column creates a trailing “Bernoulli effect,” which controls the close phase.
hope it helps!!
What is the relationship between the speed of impact and the dropping height?
A tourist stands at the top of the Grand Canyon, holding a rock, overlooking the valley below. Find the final velocity, and displacement of the rock after 4.0 seconds give the three initial conditions listed below.
a. The rock is dropped vertically from rest
b. The rock is tossed vertically upward with 8.0 m/s of speed
c. The rock is tossed vertically downward with 8.0 m/s of speed TV TV
Answer:
a. Vf = 39.24 [m/s]
b. Vf = 31.24 [m/s]
c. Vf = 47.24 [m/s].
Explanation:
To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.
[tex]v_{f}=v_{o}+g*t[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (when the rock is dropped)
g = gravitational acceleration = 9.81 [m/s²]
t = time = 4 [s]
a.
[tex]v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s][/tex]
b.
In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.
[tex]v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s][/tex]
The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.
c.
[tex]v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s][/tex]
Ramas weight is 40 kg. She is carrying a load of 20 kg up to a height of 20 m. What work does she do? What work does she do?
Answer:
The work done by Ramas is 3920 N.
Explanation:
Given;
mass of the load lifted by Ramas, m = 20 kg
height through which the load is lifted, h = 20 m
The work done by Ramas is equal to gravitational potential due to the height in which the load is lifted.
W = PE = mgh
where;
g is acceleration due to gravity = 9.8 m/s²
W = 20 x 9.8 x 20
W = 3920 N.
Therefore, the work done by Ramas is 3920 N.
Which of the following are single-displacement reactions?
A Mg (s) + 2H,0 (g) → Mg(OH)2 (aq) + Hz (g)
B. 2C,H6 (g) + 70, (g) → 6H,0 (9) + 4CO, (g)
c. AgNO3 (aq) + NaCl (aq) → AgCl (s) + NaN3 (aq)
D. Clz (9) + KBr (aq) → KCI (aq) + Br2 ()
Multiple answer are allowed!!!
Answer:
A & D
Explanation:
A single-displacement reaction is a chemical reaction whereby one element is substituted for another one in a compound and thereby generating a new element and also a new compound as products.
From the options, only options A & D fits this definition of single-displacement reactions.
For option D: Both left and hand and right hand sides each have one element and one compound. We can see that K is substituted from KBr to join Cl to form KCl and Br2 on the right hand side.
For option A: Both left and hand and right hand sides each have one element and one compound. We can see that OH is substituted from 2H2O to join Mg to form Mg(OH)2 and H2 on the right hand side.
The other options are not correct because they don't involve only and element and a compound on each side of the reaction.
Do this work if someone give correct answer I make her brainliest do this worksheet please
Sry,I only know the answer of q2
Chlorine is a non metal because it is bad conductor of heat and sodium is a metal because it is good conductor of heat.
The 3 ways in which metal is different from non metal are given below:
1)metal are good conductor of heat but nonmetal are bad conductor of heat.
2)metals are malleable but non metal aren't malleable.
3)metals are generally ductile but non metal aren't ductile.
Hope it will helpyou!
Answer:
Explanation:Chlorine is a non metal because it is bad conductor of heat and sodium is a metal because it is good conductor of heat.
The 3 ways in which metal is different from non metal are given below:
1)metal are good conductor of heat but nonmetal are bad conductor of heat.
2)metals are malleable but non metal aren't malleable.
3)metals are generally ductile but non metal aren't ductile
what is the correct answer?
Answer:
3.2
Explanation:
I remember taking this quiz and I think that one is correct
Place the molecules in the list in order with the smallest molecules at the top and largest molecules at the bottom: starch molecule, water molecule, glucose molecule, carbon dioxide molecule, protein molecule, amino acid molecule, oxygen molecule
Explanation:
list in order with the smallest molecules at the top and largest molecules at the bottom:
1.Oxygen
2.Water
3.Carbon dioxide
4.amino acid
5.Glucose
6. Starch
7. Protein
The molecules can be arranged as follows with the smallest at the top is oxygen, water, carbon dioxide, amino acid, glucose, starch, protein.
The given molecules;
starch, water, glucose, carbon dioxide, protein, amino acid, oxygen
The molecular weight of the given compounds is listed as follows;
water -------- 18 g/mol
glucose ------- 180.2 g/mol
starch (2 or more glucose) ------ 360 g/mol
carbon dioxide ------ 44 g/mol
protein -------- 20,000 g/mol
amino acid (glycine) ----- 75 g/mol
oxygen -------- 16 g/mol
Thus, the molecules can be arranged as follows with the smallest at the top;
oxygenwatercarbon dioxideamino acidglucosestarchproteinLearn more here:https://brainly.com/question/19537339
A 0.05 kg golf ball at rest was hit with a force of 200N. The golf ball left the club at an angle of 35° to the horizontal at 49m/s. What was the final velocity as it hits the ground
Note that when the ball is in the air, the only force acting on it is the downward pull of gravity, so the force of the swing is a red herring.
The ball hits the ground at the same height from which it was hit, so its final velocity will have the same magnitude of 49 m/s, but pointing at an angle of 35° below the horizontal.
A man is standing on the edge of a 20.0 m high cliff. He throws a rock horizontally with an initial velocity of 10.0 m/s.
a. How long does it take to reach the ground?
b. How far does the rock land from the base of the cliff?
Answer:
a. t = 2.02 s
b. d = 20.2 m
Explanation:
Horizontal Motion
If an object is thrown horizontally from a height h with a speed v, it describes a curved path ruled exclusively by gravity until it eventually hits the ground.
The time the object takes to hit the ground can be calculated as follows:
[tex]\displaystyle t=\sqrt{\frac{2h}{g}}[/tex]
The time does not depend on the initial speed.
The range or maximum horizontal distance traveled by the object can be calculated by the equation:
[tex]\displaystyle d=v.t[/tex]
The man standing on the edge of the h=20 m cliff throws a rock with an initial horizontal speed of v=10 m/s.
a.
The time taken by the rock to reach the ground is:
[tex]\displaystyle t=\sqrt{\frac{2*20}{9.8}}[/tex]
[tex]\displaystyle t=\sqrt{4.0816}[/tex]
t = 2.02 s
b.
The range is:
[tex]\displaystyle d=10\cdot 2.02[/tex]
d = 20.2 m
If the scale model works as predicted, the final product is guaranteed to be flawless.
•True
•False
Answer: true
Explanation:
If the scale model was working as it was predicted to work, then the final product is expected to be flawless. It should be a reasonable product if the scale model is working. Our answer is the option True.
1. What is the speed of a runner who runs 400 meters in 40
seconds?
Answer:
10 m/s
Explanation:
Speed = Distance / Time
Speed = 400 / 40
Speed = 10
Unit = meters per second = m/s
An object has a momentum of 56.59 kg*m/s and a velocity of 5.3 m/s. What 1 point
is the mass of the object? *
Answer:
10.68 kgExplanation:
The mass of the object can be found by using the formula
[tex]m = \frac{p}{v} \\ [/tex]
p is the momentum
v is the velocity
From the question we have
[tex]m = \frac{56.59}{5.3} \\ = 10.677358...[/tex]
We have the final answer as
10.68 kgHope this helps you
Which phrase describes blackbody radiation?
O A. Radiation that is absorbed by an object as it warms
O B. Light given off by an object based on its temperature
O C. Radiation that explains the wave model of light
O D. Light given off by an object based on its color
Answer:
b
Explanation:
The phrase that describes blackbody radiation is the radiation that is absorbed by an object as it warms.
What is blackbody radiation?Blackbody radiation is a radiation produced by heated objects, particularly from a blackbody.
In physics, a blackbody, approximated by a hole in a hollow black sphere, absorbs all incident electromagnetic radiation and reflects none.
Therefore, the phrase that describes blackbody radiation is the radiation that is absorbed by an object as it warms.
Learn more about blackbody radiation at: https://brainly.com/question/13934832
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A car is stopped for a traffic signal. When the light turns green, the car accelerates, increasing its speed from zero to 5.27 m/s in 0.833 s. What linear impulse and average force does a 69.8 kg passenger in the car experience
Answer:
See explanation
Explanation:
From Newton's law; the rate of change of momentum is proportional to the impressed force. Hence;
F.t = mv- mu
F= force
t= time
m= mass
V= final velocity
u = initial velocity
since u = 0, mv= 0
F= MV/t
F= 69.8 × 5.27/0.833
F= 442 N
Impulse = Ft= 442 × 0.833= 368 Ns
Calculate the gravitational force between a 4.0 x 10^8 kg mass and a 2.8 x 10^5 kg mass separated by a distance of 1.0 x 10^4 m.
Answer:
[tex]F_{g}=7.4704\times10^{-5}[/tex]
Explanation:
Givens: d = 1.0 × [tex]10^{4}[/tex] [tex]m_{1} = 4.0 x 10^{8}[/tex] [tex]m_{2} = 2.8[/tex]×[tex]10^{5}[/tex]
Required: [tex]F_{g}=?[/tex]
Formula: [tex]F_{g}= \frac{(6.67x10^{-11})(m_{1})(m_{2}) }{d^{2}}[/tex] (6.67x10^-11 is the gravitational constant)
[tex]F_{g}=\frac{\left(6.67\cdot10^{-11}\right)\left(4.0\cdot10^{8}\right)\left(2.8\cdot10^{5}\right)}{\left(1.0\cdot10^{4}\right)^{2}}[/tex]
[tex]F_{g}=7.4704\times10^{-5}[/tex]
Uncle Harry weighs 750 N. What is his mass in kg?
Answer:
W = MG
750 = M * 10
M = 750/10
M = 75 kg
Answer:
76.479 Kilograms Force (kgf)
Explanation:
When a 54.9-g tennis ball is served, it accelerates from rest to a speed of 45.1 m/s. The impact with the racket gives the ball a constant acceleration over a distance of 35.1 cm. What is the magnitude of the net force acting on the ball
Answer:
F = 159.07 N
Explanation:
Given that,
Mass of a tennis ball, m = 54.9 g = 0.0549 kg
It accelerates from rest to a speed of 45.1 m/s.
The impact with the racket gives the ball a constant acceleration over a distance of 35.1 cm = 0.351 m
We need to find the magnitude of net force acting on the ball.
Let a be the acceleration of the ball. Using third equation of motion to find it.
[tex]v^2-u^2=2ad\\\\a=\dfrac{v^2-u^2}{2d}\\\\a=\dfrac{(45.1)^2-(0)^2}{2\times 0.351}\\\\=2897.45\ m/s^2[/tex]
Net force,
F = ma
F = 0.0549 kg × 2897.45 m/s²
= 159.07 N
Hence, the net force acting on the ball is 159.07 N.
How much work is it to lift a 2.0 kg sack of potatoes vertically 6.5 m?
Answer:
Therefore, the work done to lift a 20 kg sack of potatoes of potatoes vertically 6.5 m is 1, 274 J.
What is the velocity of v2 if m1=82kg v1= 25 m/s m2=60kg?
Given :
[tex]m_1 = 82 \ kg\\\\v_1 = 257 m/s\\\\m_2 = 60 kg[/tex]
Let, us assume that momentum is conserved during the process.
To Find :
The velocity [tex]v_2[/tex] .
Solution :
Applying conservation of momentum :
Initial momentum = Final momentum
[tex]m_1v_1 = m_2v_2\\\\82\times 257=60\times v_2\\\\v_2 = \dfrac{82\times 257}{60}\ m/s\\\\v_2 = 351.23\ m/s[/tex]
Hence, this is the required solution.
A ship is travelling due east at 30 km/hr and a boy runs across the deck
in a south west direction at 10 km/hr. Find the velocity of the boy
relative to sea.
Answer:
Vr = 20 [km/h]
Explanation:
In order to solve this problem, we have to add the relative velocities. We must remember that velocity is a vector, therefore it has magnitude and direction. We will take the sea as the reference measurement level.
Let's take the direction of the ship as positive. Therefore the boy moves in the opposite direction (Negative) to the reference level (the sea).
[tex]V_{r}=30-10\\V_{r}=20 [km/h][/tex]
A cello string is 0.695 m long, and transmits waves at 204 m/s. What frequency does it produce? (Unit = Hz)
Answer:
ν=293.53 Hz
Explanation:
ν= speed/λ
speed = 204 m/s
λ=0.695 m
v = 204 m/s * 1/0.695m
meters cancels out
1/s = Hz
v = 204/0.695 Hz
ν=293.53 Hz
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apparently it is wrong, but my work and online calculator says otherwise... possibly round your answer? I'm not sure then...
Answer:146.75
Explanation:
Un cuerpo se lanza hacia arriba con 50 m/s . ¿A qué altura se encuentra cuando su rapidez es 20 m/s por segunda vez? (g = 10 m/s ^ 2) .
Answer:
105 m
Explanation:
Given that the initial velocity of the body, u= 50 m/s in upward direction.
Acceleration due to gravity, g= 10 m / [tex]s ^ 2[/tex] in the downward direction.
Let h be the height of the body when the velocity of the body is 20 m/s.
As the gravitational force acting in the downward direction, so taking it negative as
a= - 10 m/[tex]s ^ 2[/tex] in the upward direction.
By using the equation of motion [tex]v^2=u^2+2as[/tex] ...(i)
Here, u= 50 m/s
v= 20 m/s
[tex]a=- 10 m/s^2[/tex]
s=h
Putting all the values in the equation (i), we have
[tex]20^2=50^2+2(-10)h \\\\400=2500-20h \\\\h=\frac{2500-400}{20} \\\\h=105 m[/tex]
Hence, the height of the body is 105 m.
A 6 kg block is released from rest at the top of an incline, as shown above, and slides to the bottom. The incline is 1.97 m long, is inclined at an angle of 29.4°, and the coefficient of kinetic friction between the block and the incline is 0.21.
a. Calculate the normal force the incline puts on the block.
The net force on the block acting perpendicular to the incline is
∑ F = n - w cos(29.4°) = 0
where n is the magnitude of the normal force and w = m g is the weight of the block.
The equation itself comes from splitting up the forces acting on the block into components pointing parallel or perpendicular to the incline. The only forces acting on the block in the perpendicular direction are the normal force and the perpendicular component of the block's weight.
Solve for n :
n = m g cos(29.4°)
n = (6 kg) (9.80 m/s²) cos(29.4°)
n ≈ 51.2 N
What is the kinetic energy of a 0.5 kg puppy that is running 1.5m/s
Answer: Well the answer is KE = 5.625E-7 i just don't know the units for it...
Hope this helps....... Stay safe and have a Merry Christmas!!!!!!!!!! :D