Letter B
without a medium, there is nothing to compress, hence, no wave. A fast- medium like a gas (air) is easy to compress and allows waves to move through it easily. a slow medium, like a liquid, is still pretty fast, but not as fast as air.
A 700 kg car going 12 m/s speeds up to 30.6 m/s in 7 seconds. How much work was done to increase its speed?
Answer:
Approximately [tex]2.8 \times 10^{5} \; \rm J[/tex] (assuming that the car is moving on level ground, and that there is no friction to hinder the motion of the car.)
Explanation:
Formula for the kinetic energy, [tex]\rm KE[/tex], of an object of [tex]m[/tex] travelling at velocity [tex]v[/tex]:
[tex]\displaystyle \text{KE} = \frac{1}{2}\, m \cdot v^{2}[/tex].
Let [tex]v_1[/tex] and [tex]v_2[/tex] denote the velocity of this car before and after the acceleration.
Kinetic energy of this car before the acceleration:
[tex]\begin{aligned}\text{KE}_1 &= \frac{1}{2}\, m \cdot {v_1}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (12\; \rm m \cdot s^{-1})^{2} \\ &\approx 5.0 \times 10^{4}\; \rm J\end{aligned}[/tex].
Kinetic energy of this car after the acceleration:
[tex]\begin{aligned}\text{KE}_2 &= \frac{1}{2}\, m \cdot {v_2}^{2} \\ &= \frac{1}{2} \times 700\; \rm kg \times (30.6\; \rm m \cdot s^{-1})^{2} \\ &\approx 3.3\times 10^{6}\; \rm J\end{aligned}[/tex].
Assume that this car was travelling on level ground. Also assume that there is no friction to hinder the motion of this car. The work of the engine of this car would be equal to the amount of [tex]\rm KE[/tex] that the car has gained:
[tex]\rm KE_2 - KE_1 \approx 2.8\times 10^{5}\; \rm J[/tex].
what happens to the mechanical energy of an apple as it falls from a tree?
Answer:
When the apple falls from the tree, it has some gravitational potential energy due to its height. Now, When it starts falling, the Gravitation Potential energy will starts converting into the Kinetic Energy. When the apple is about to strikes the ground, the Gravitational Potential energy have been converted into the Kinetic Energy.
Explanation:
The potential energy will be low when its kinetic energy is high and vice versa. But the mechanical energy remains conserved.
What is mechanical energy?Mechanical energy can be explained as the sum of kinetic energy and potential energy that can be used to do work. Mechanical energy can be described as the energy of a body due to its motion or position.
The total mechanical energy of a physical system is conserved as the energy can not be created or destroyed. The mechanical energy of a physical system can only be transformed from one form to another when the forces acting work are conservative in nature.
Each force is related to potential energy form and the energy changes between different kinds of potential energy and kinetic energy but the total energy remains constant.
The mechanical energy of the apple remains conserved. As the apple falls its potential energy is converted into kinetic energy.
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NHT0015
16. A metal rod is heated increasing its temperature
by 10°C. The fractional change in its length is
1 *10-4. If a plate of same metal is heated raising
its temperature by 5°C, the fractional change in
its area will be .-
(1) 1 x 10-4
(2) 0.5 x 10-4
(3) 2 x 10-4
(4) 3 x 10-4
Answer:
(1) 1×10⁻⁴
Explanation:
From the question,
α = (ΔL/L)/(ΔT)............. Equation 1
Where α = linear expansivity of the metal plate, ΔL/L = Fractional change in Length, ΔT = Rise in temperature.
Given: ΔL/L = 1×10⁻⁴, ΔT = 10°C
Substitute these values into equation 1
α = 1×10⁻⁴/10
α = 1×10⁻⁵ °C⁻¹ .
β = (ΔA/A)/ΔT................... Equation 2
Where β = Coefficient of Area expansivity, ΔA/A = Fractional change in area.
make ΔA/A the subject of the equation
ΔA/A = β×ΔT.......................... Equation 3
But,
β = 2α.......................... Equation 4
Substitute equation 4 into equation 3
ΔA/A = 2α×ΔT................ Equation 5
Given: ΔT = 5°C, α = 1×10⁻⁵ °C⁻¹
Substitute into equation 5
ΔA/A = ( 2)×(1×10⁻⁵)×(5)
ΔA/A = 10×10⁻⁵
ΔA/A = 1×10⁻⁴
Hence the right option is (1) 1×10⁻⁴
A negative charge of 4.0 x 10 C and a positive charge of 7.0 x 10 C are separated by 0.15 m. What is
the force between the two charges?
Answer:
112×10^12N
Explanation:
We use the following equation to find the force between two charges that are away from each other at a particular distance:
F=k×q1×q2/r^2 F=9×10^9×4×10×7×10/(0.15)^2 F=252×10^11/0.225 F=1120×10^11=112×10^12how much kinetic energy does an 8 kg bowling ball have when it is thrown 9 m/s. down the alley
Answer:
324 J
Explanation:
KE= 1/2 m*v^2
1/2*8*9^2
324 joules (=^w^=) woof woof
Calculate the weight(W) of a 40 Kg bowling ball?
W = m(Kg) x g (9.8 m/s2)
Answer:
392 N
Explanation:
Mass of the ball=40kg
g=9.8m/s^2
Weight(w)=40×9.8
=392N
An 8.8-magnitude earthquake in Chile in 2010 killed more than 700 people. On January 12, 2010, a less powerful earthquake, measuring 7.0, killed more than 200,000 in Haiti. Why do you think this happened?
Answer:
The main reason for this is the engineering and technology driven building construction in Chile than in Haiti
Explanation:
The main reason for this is the engineering and technology driven building construction in Chile than in Haiti. Most of the buildings in Haiti do not fit in the building byelaws norms as most of them were constructed in a short period of time with less engineering and at cheaper rate. While building in Chile were built adhering to the building codes and byelaws.
The base of the building is Chile were separated from each other using the “base isolation” technology and the were also more flexible as compared to the buildings in Haiti.
The skyscrapers in Chile were constructed in a way that they can float on the arrangements of ball bearings and padded cylinders
What is destructive interference?
a) Occurs when the crest of one wave meets the trough of another wave as they travel from two different points in the same direction and at the same frequency.
b) Occurs when the crest of one wave stays separate from another wave and they continue moving in their original direction.
Answer quickly, please!
Answer:
a
Explanation:
occurs when the crest of one wave meets the trough of another wave as they travel from two different points in the same direction and at the same frequency
Which statements did both Aristotle and Ptolemy assume? Select two options.
The Sun was the center of the solar system.
Bodies in space traveled in circles.
Epicycles explained the “looping” movement of the planets.
The planets revolved around the Earth.
The stars in the sky are other suns.
Answer:
Bodies in space traveled in circles.
The planets revolved around the Earth.
Explanation:
Answer: b and d
Explanation:
got it right
GIVING BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 20pts-
Answer:
B
Explanation:
inside of a balloon is gas so it has room to move freely
Explain one inference scientists made about the interior of the Earth based on seismic waves. Use the words S & P waves in your answer. Use the word refract/bend in your answer
Answer:
"An earthquake radiates P and S waves in all directions and the interaction of the P and S waves with Earth's surface and shallow structure produces surface waves. Near an earthquake the shaking is large and dominated by shear-waves and short-period surface waves." please rephrase this in your own words.
Explanation:
Im not sure if this helps but credits to: eqseis.geosc.psu.edu › Notes › waves_and_interior
Describe the energy transformations that must occur from batteries to the light in remote control. Can you think of any other objects where the same energy transformation occurs?
Answer:
Pressing the button: Mechanical to electrical
Waste energy from this step: Mechanical to heat
Converting electrical signal to IR: electrical to electromagnetic (infrared rays)
Waste energy from this step: electrical to heat
Chemical energy from battery: chemical to electrical
Explanation:
How does this relate to Newton's second law?
Two balls with different weights (tennis ball and basket ball) are dropped from the same height to see which one will land first
Answer:
In ideal case, when no resistive forces are present then both the balls will reach the ground simultaneously. This is because acceleration due to gravity is independent of mass of the falling object. i.e. g = GM/R² where G = 6.67×10²³ Nm²/kg², M = mass of earth and R is radius of earth.
Let us assume that both are metallic balls. In such case, we have to take into account the magnetic field of earth (which will give rise to eddy currents, and these eddy currents will be more, if surface area will be more) and viscous drag of air ( viscous drag is proportional to radius of falling ball), then bigger ball will take slightly more time than the smaller ball.
Explanation:
In ideal case, when no resistive forces are present then both the balls will reach the ground simultaneously. This is because acceleration due to gravity is independent of mass of the falling object. i.e. g = GM/R² where G = 6.67×10²³ Nm²/kg², M = mass of earth and R is radius of earth.
Let us assume that both are metallic balls. In such case, we have to take into account the magnetic field of earth (which will give rise to eddy currents, and these eddy currents will be more, if surface area will be more) and viscous drag of air ( viscous drag is proportional to radius of falling ball), then bigger ball will take slightly more time than the smaller ball.
On a cold day, the speed of sound in air is 330 m/s. A note with a frequency of 1,320 Hz is played on an instrument. What is the wavelength of that sound wave? 0.25 m 4 m 1,650 m 435,600 m
Answer:
0.25 m
Explanation:
Given that,
The speed of sound, v = 330 m/s
The frequency of the note of the instrument, f = 1320 Hz
We need to find the wavelength of the sound wave.
We know that,
Wavelength, [tex]\lambda=\dfrac{v}{f}[/tex]
Put all the values,
[tex]\lambda=\dfrac{330}{1320}\\\\\lambda=0.25\ m[/tex]
So, the wavelength of the sound wave is equal to 0.25 m.
Answer: .25m edge 2020
Explanation:
The starting temperature of a beaker of water is 60 F. The thermometer shows the temperature of the same beaker of water after being heated on a hot plate. How much higher is the temperature after the water is heated? Record your answer below.
Answer:
The temperature after the water is heated is higher by 152°F
Explanation:
The starting temperature of a beaker of water = 60 F
Temperature of water in heated condition = 212°F
The temperature rises by 212°F - 60°F = 152°F
The temperature after the water is heated is higher by 152°F
if i ask wat r the application of simple machine some of u will say-----> Simple machines that are widely used include the wheel and axle, pulley, inclined plane, screw, wedge and lever. While simple machines may magnify or reduce the forces that can be applied to them, they do not change the total amount of work needed to perform the overall task.
but actually the application of simple machine is
i) they transfer force from one point to another
ii) They accelerate the rate of doing work
iii) the multiply force
Answer:
DID NOT
UNDER STAND
Explan it a littlebit
You drive a car for 2.0 h at 60 km/h, then for another 3.0 h at 85 km/h. What is your average velocity
Answer:
Explanation:
Average velocity is found in the total displacement experienced in the trip divided by the total time it took to make this trip. If, for the first 2.0 hours, the car travels at 60 km/hr, then in 2.0 hours the car can travel 120 km; if it then travels for 3.0 at 85 km/hr, it can travel 255 km in the same direction. The total time this took was 5.0 hours. So doing the math and rounding correctly by following the rules for the adding and subtracting of sig fig's:
[tex]v=\frac{120+255}{5.0}=\frac{380}{5.0}=76\frac{km}{hr}[/tex]
If you do not round when you add, the average velocity is 75 km/hr
I have no questions.
Answer: happy Ramadan
Explanation: thanks
the atomic mass unit (amu) is
a. the mass of a single atom of carbon
b. one millionth of a gram
c. approximately the mass of a proton
d. approximately the mass of an electron
(dont send me a link please)
Answer:
The correct option is (a).
Explanation:
One Atomic mass unit is the mass of an atom. It is defined as the mass of a single carbon -12 at rest.
The relation between amu and kg is given by :
[tex]1\ amu=1.66\times 10^{-27}\ kg[/tex]
Hence, one amu is equal to the mass of a single atom of carbon.
A car traveling towards east at 40 m/s and turns towards left and travels at same speed. The change in velocity is
Answer:
Explanation:
In physics the term velocity is always a vector. All that means is that it's got a direction with it. which also means this vehicle that was traveling in the east direction and then turned left is and is now , maybe traveling in a north direction. Making the guesses that the car was traveling due East and is now traveling due North, then the car has changed it's velocity by 40 m/s. By The Way do you happen to know how fast 40 m/s is? it's about 144 Kph :0 or about 90 MPH so this guy is also speeding :D, write him a ticket ... :P
A ray of light strikes a plane mirror at an angle of incidence equal to 35°. The angle between
the incident ray and the reflected ray is
A)
70°
B)
0°
C)
55°
D)
35°
Answer:
55 degrees
Explanation:
A ray of light strikes a plane mirror at an angle of incidence. The angle between the incident ray and the reflected ray is 70°. The correct option is A.
What is law of reflection?The law states that angle of incidence of the incident ray is equal to the angle of reflection through a plane surface.
Here, angle of incidence of light on a plane mirror is 35°, then the angle of reflection will also be 35°.
i = r = 35°
Then the angle between the incident ray and the reflected ray will be
i +r = 35 + 35 =70°
Thus, the correct option is A.
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a pine raft (density = 373 kg/m^3) has a volume of 1.43 m^3. How much of the raft's volume is below the water line? Unit is m^3
Answer: 0.5334
Explanation:
i got it right on accellus :p
Volume of value V = 0.5333 [tex]m^{3}[/tex] is below the water line .
What is Archimedes principal ?Archimedes' principle states that a body immersed in a fluid is subjected to an upwards force equal to the weight of the displaced fluid.
F(b) = rho*g*V
F(b) = buoyant force
rho = fluid density
g = acceleration due to gravity
V = fluid volume
given
density of raft = 373 kg/[tex]m^{3}[/tex]
volume of raft = 1.43 [tex]m^{3}[/tex]
since, density = mass / volume
mass of raft = density * volume
= 373 * 1.43 = 533.3 kg
using Archimedes principal
Force = density of liquid * volume of liquid displaced * acceleration due to gravity
mg = 1000 * V * 9.8
533.3 * 9.8 = 1000 * V * 9.8
V = 0.5333 [tex]m^{3}[/tex]
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what is the acceleration of a box weighing 666N if a force of 777N is applied to it
Answer:
6.67
Explanation:
force=mass*gravity(10)
666/10=66.6
777/66.6=11.6666667
round off
What does non-contact forcemean?
Answer:
A non-contact force is a force applied to an object by another body that is not in direct contact with it.
Explanation:
¿Cuál es la formula para resolver la caída libre?
Caída Libre
h= v0 t+1/2 g t2
vf = v0 + g t
?
How much kinetic energy does a 2 kg ball have if it is going 5 m/s ?
Explanation:
mass(m)=2 kg
velocity(v)=5m/s
Now,
Kinetic energy(K.E.)=1/2mvsq
=1/2×2×5sq
=25
where,sq=square(2)
After the full moon, the moon begins its shrinking or_phases. During these phases, the light side of the moon is on the_
A. Waning, left
B. Waxing, right
C. Waxing, left
D. Waning, right
A complete, unbroken path through which electric charges can flow is a(n)
a.
electric circuit.
b.
electrical resistance.
c.
magnetic field line.
d.
magnetic pole.
Answer:
a.
electric circuit.
Explanation:
A path through which electric charges flow. A continuous, unbroken path through which electrons can flow is a closed circuit. Charges, or current, can flow only through a closed circuit. A break or opening in a circuit creates an open circuit.
Answer:
The answer would be A
Explanation:
An electric circuit.
Hope this helped!
"No one's like me, I'm Harley frickin' Quinn"!
-Harley Quinn (Birds of Prey)
Which event occurs during high tide?
All of Earth’s ocean levels rise.
The moon’s orbit is closer to Earth.
The gravity of the Sun and moon cause the Earth’s crust and water to bulge.
Earth’s crust and water are being pulled in opposite directions by the Sun and moon.
Answer:
(B) The moon’s orbit is closer to Earth.
Explanation:
Answer:
B
Explanation:
This diagram shows a heating curve for water.
At which segment does freezing occur?
The answer is B.) W-V
Hope this helps
Answer:
it is B
Explanation:
Because I agree with her and also got 100