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
De-Broglie postulated that the relationship, lambda=h/p is valid for relativistic particles. Find out the de-Broglie wavelength for an electron whose kinetic energy is 3MeV.
Given :
An electron with kinetic energy of 3 MeV.
To Find :
The de-Broglie wavelength for that electron.
Solution :
We know, de-Broglie wavelength for an electron with kinetic energy K.E is given by :
[tex]\lambda = \dfrac{h}{\sqrt{2m(K.E)}}[/tex]
Putting all given values in above equation, we get :
[tex]\lambda = \dfrac{6.626\times 10^{-34}}{\sqrt{2\times 9.1\times 10^{-31}\times 3\times 10^6 \times 1.6\times 10^{-19}}}\\\\\\\lambda = 7.089 \times 10^{-13} \ m[/tex]
Hence, this is the required solution.
Write true if the statement is correct and false if the statement
1. Magnetic poles always appear in pair.
2. Iron and nickel are examples of magnetic materials.
3. The two ends of a magnet are called magnetic poles.
4. Two similar magnetic poles attract each other
5. If one end of an iron bar attracts one pole of a com
Grade 7 Physics
then the iron bar must be a magnet.
Match the terms in column A with the phrases in colu
B
Answer:
true false
Explanation:
Answer:
1.true
2.true
3.true 4.false 5.true
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
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.
What is the relationship between the speed of impact and the dropping height?
Solve ASAP please!!!
Which of these best describes science?
A-Science is the study of fundamental problems such as existence, values, and reason.
B-Science is the collection of all living things on Earth.
C-Science is a body of knowledge and a process of discovery that allows people to understand the natural
world.
D-Science is the practice of diagnosing, treating, and preventing disease.
what is the speed of a 330kg beam dropped from 40m
Answer:
28 m/s
Explanation:
We can use this constant acceleration kinematic equation to find the speed of this beam as it is dropped from 40 m.
Since the object is dropped vertically downwards, we know that the object is in free-fall.
The acceleration of this object is -g, which is -9.8 m/s² since we are making the positive direction upwards and the negative direction downwards.
The initial velocity is 0 m/s since the object is dropped and starts from rest.
The final velocity is what we are trying to solve for.
The displacement in the y-direction is 40 m.
Now we can see which equation contains these 4 variables:
v² = v₀² + 2aΔxPlug in the known variables.
v² = (0)² + 2(-9.8)(-40)Simplify this equation.
v² = 784Take the square root of both sides.
v = 28 m/sThe speed of the 330 kg beam dropped from 40 m is 28 m/s.
Answer:
28 m/sExplanation:
Given information :
mass = 330kg
height =40m
v = √2gh
Where ;
g = acceleration due to gravity = 9.8 or 10 m/s
h = height
how much total energy of the beam just as it hits the ground =
mgh
[tex]330\times 10\times 40\\\\\\=132000[/tex]
Speed at which the beam will hit the ground :
[tex]v = \sqrt{2\times 10\times40} \\\\=\sqrt{800}\\\\=20\sqrt{2}\\\\v=28.28427[/tex]
A communication satellite is in a circular path orbit around Earth. If the speed of the satellite is constant, the net force acting on the satellite ____.
Answer:
is changing in direction, but constant in magnitude
Explanation:
This question is a bit tricky since the velocity of the satellite is changing, but the speed is constant.
Speed is simply a measure of how fast you are going. It doesn't matter where you're going, just how quickly.
Velocity, on the other hand, does care about which direction you're going. For example, it could be then when you travel right, your velocity is positive, and when you travel left, your velocity is negative. This is the similar for a 2D shape like a circular orbit
Since we know velocity is changing, there must be acceleration which changes that velocity (since acceleration is the change in velocity: going from 0 to 60 mph, for example)
Thus, with a non-zero net acceleration, we know that there must be a force that is changing in direction, but constant in magnitude (since the orbit is a circle, and always attracted to the center of the Earth at equal distance).
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.
If an object has a weight of 4050 N near the surface of the Earth, what is its mass?
Answer:
417.5 kg
Explanation:
Since the gravitational for of attraction F, equals the weight of the object W when its close to the earth, F = GMm/R² = W = mg where m = mass of object and g = acceleration due to gravity close to the earth = 9.8 m/s².
g = GM/R² where g = acceleration due to gravity close to the earth, G = universal gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of earth = 5.927 × 10²⁴ kg and R = radius of earth = 6.4 × 10⁶ m
So, g = GM/R²
= 6.67 × 10⁻¹¹ Nm²/kg² × 5.927 × 10²⁴ kg/(6.4 × 10⁶ m)²
= 39.53 × 10¹³ Nm²/kg ÷ 40.96 × 10¹² m²
= 9.65 N/kg
≅ 9.7 N/kg
= 9.7 m/s²
Since W = 4050 N and W = mg
m = W/g = 4050 N/9.7 m/s²
= 417.53 kg
≅ 417.5 kg
So, the mass of the object is 417.5 kg
In an A.C circuit current leads voltage by phase π/2 then circuit is
Answer:
capacitive
Explanation:
In a capacitive circuit, current is proportional to the derivative of the voltage. For a sinusoidal excitation, this means current is at the highest level when voltage is increasing through zero. That is, current leads the voltage.
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
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
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]
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
I WILL MARK BRAINLIEST!
A 2.0 kg bullet is fired into a sandbag sitting on a wagon. The combined mass of the wagon and the sandbag is 4.5 kg. a) If the wagon/sandbag/bullet moved together with a speed of 0.22 m/s immediately after impact with the bullet, with what speed did the bullet enter the sandbag? b) Is this an elastic or inelastic collision? Explain.
Answer:
To answer your question use the code ICE on here to get your answer works every time for me hope this helps
difference between lower fixed point and upper fixed point
Answer:
The lower fixed point, or ice point, is the temperature of pure melting ice at normal atmospheric pressure. The upper fixed point, or steam point, is the temperature of pure boiling water at normal atmospheric pressure.
Explanation:
What is an astronomical unit or AU
Answer:
D
Explanation:
Answer:
Astronomical Unit = 4.8481×10−6 pc; 1.5813×1.
Or even AU = Equal to
Explanation:
A string of length 0.67 m and mass 2.0 g is held at both ends under tension. The string
produces a 700 Hz tone when it vibrates in the fourth harmonic. During this event, what is the
wavelength of the standing wave in the string?
.34
.55
.61
.45
.49
Answer:
The value is [tex]\lambda = 0.335 \ m[/tex]
Explanation:
From the question we are told that
The length of the string is [tex]l = 0.67 \ m[/tex]
The mass is [tex]m = 2.0 \ g = 0.002 \ kg[/tex]
The frequency produced at fourth harmonic vibration(i.e n =4 ) is [tex]f = 700 \ Hz[/tex]
Generally the wavelength of the string is mathematically represented as
[tex]\lambda = \frac{ 2L }{n }[/tex]
=> [tex]\lambda = \frac{ 2 * 0.67 }{ 4 }[/tex]
=> [tex]\lambda = 0.335 \ m[/tex]
What is the mathematical relationship between wavelength and velocity? PLZ HELP MEEE
Answer: wavelength is the length of the wave, example the length of a sound wave.
Velocity is also known as speed.
Explanation:
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.
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]
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.
A 100 kg skateboarder sits at the top of a 10 m halfpipe, ready to go down the ramp. What will be his velocity when
he is 4 m off of the ground?
Answer:
v = 10.85 m/s
Explanation:
We will apply the law of conservation of energy to the skateboarder. Neglecting the frictional effects, the law of conservation of energy can be written as:
[tex]Loss\ in\ Potential\ Energy\ of\ Skateboarder = Gain\ in\ Kinetic\ Energy\ of\ Skateboarder[/tex][tex]mg\Delta h = \frac{1}{2}mv^2\\\\v^2 = 2g\Delta h\\v = \sqrt{2g\Delta h} \\[/tex]
where,
v = velocity of skateboarder = ?
g = acceleration due to gravity = 9.81 m/s²
Δh = change in height = 10 m - 4 m = 6 m
Therefore,
[tex]v = \sqrt{{(2)(9.81\ m/s^2})({6\ m})}}[/tex]
v = 10.85 m/s
A woman has a mass of 55 kg on earth. what would be the women's weight on the moon? (The moon’s gravity is 1.6 N).
Answer:
i dont know the answer sorry have a good day
Explanation:
hsjsjdkdkdkdkdkdk
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
A Force is applied onto a mass causing it to accelerate. If the same Force was applied to a SMALLER mass, what would happen to that acceleration?
1. The acceleration would increase
2. The acceleration would stay the same
3. The acceleration would decrease
4. The acceleration would change direction
Answer:
1. The acceleration would increase.
Explanation:
This is because according to Newton's law, the less mass there is, the more velocity.
Two forces act in opposite directions on a wood block. What will happen if the forces are unbalanced?
A. The block will balance the forces.
B. The forces will reverse direction.
C. The mass of the block will change.
D. The position of the block will change.
Answer:
D
Explanation:
If two unequal forces act in opposite directions, one larger force must cancel out the smaller force,
leaving the net force to be some number in one direction.
Take for example a game of tug-of-war; there are two OPPOSITE forces (groups of people) acting on the rope, one force is pulling with a force in the negative direction while the other force is pulling in the positive direction.
If the forces on the rope were unequal, then the stronger force (group) will pull everything in their direction.
The same will happen on two unequal forces of opposite directions acting on a wooden block. Therefore, since the resultant force will have a non-zero magnitude and direction, there will be a change in the block's motion and position.
You walk exactly 250 steps North, turn around, and then walk exactly 400 steps South. How far are you from your starting
point?
steps to the
North, South, East or West)
Answer:
150 steps south
Explanation:
250 north 250 back to start then continue south for remainder of 400 steps. 150 south