Answer:
D. Hydrogen combines with oxygen to form water.
Explanation:
Hydrogen combining with oxygen to form water is a typical example of chemical reaction.
During a chemical reaction, atoms of elements are rearranged. Most chemical reactions obey the law of conservation of mass which states that "matter is neither created nor destroyed in a chemical reaction but atoms are simply rearranged".
The other choices given are nuclear reactions. In such reactions, atoms are not rearranged but are simply destroyed and made in the process.
Answer:
D.) Hydrogen combines
Explanation:
BE HAPPY
You might think that an ultraviolet light shining on an initially uncharged electroscope would cause the electroscope to become positively charged as photoelectrons are emitted. In fact, ultraviolet light has no noticeable effect on an uncharged electroscope. Why not
Answer:
Positively Charge formation on the electroscope pulls the electrons so no emission happens.
Explanation:
Photoelectric effect is the process by which the electrons get ejected when light of certain frequency falls on the material. The energy from the electromagnetic radiation excites the electron by providing it enough energy as a result it gets ejected.
The Ultraviolet(UV) light is a form of electromagnetic radiation, If the UV radiation strikes an uncharged electroscope, it is predicted that it will cause the electrons in the electroscope to excite and to be emitted. But on the contrary no noticeable effect is observed on the electroscope this happened because when UV light makes the electroscope positively(+) charged this creates a pull for the electrons, as a result rather emitting the electrons gets pulled by the positively charged electroscope.
Therefore the positively charge formation on the electroscope hinder the electrons emission and there is no noticeable effect.
g Estimate the number of photons emitted by the Sun in a second. The power output from the Sun is 4 × 1026 W and assume that the average wavelength of each photon is 550 nm.
Answer:
The value is [tex]N = 1.107 *10^{45 } \ photons[/tex]
Explanation:
From the question we are told that
The power output from the sun is [tex]P_o = 4 * 10^{26} \ W[/tex]
The average wavelength of each photon is [tex]\lambda = 550 \ nm = 550 *10^{-9} \ m[/tex]
Generally the energy of each photon emitted is mathematically represented as
[tex]E_c = \frac{h * c }{ \lambda }[/tex]
Here h is the Plank's constant with value [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]
c is the speed of light with value [tex]c = 3.0 *10^{8} \ m/s[/tex]
So
[tex]E_c = \frac{6.62607015 * 10^{-34} * 3.0 *10^{8} }{ 550 *10^{-9} }[/tex]
=> [tex]E_c = 3.614 *10^{-19} \ J[/tex]
Generally the number of photons emitted by the Sun in a second is mathematically represented as
[tex]N = \frac{P }{E_c}[/tex]
=> [tex]N = \frac{4 * 10^{26} }{3.614 *10^{-19}}[/tex]
=> [tex]N = 1.107 *10^{45 } \ photons[/tex]
A 3 kg exercise ball is held 2m above the ground. What is the gravitational potential energy?
Answer:
58.56 J
Explanation:
Since the formula for gravitational potential energy is:
GE = m x g x h - where m = mass (kg), g = acceleration due to gravity (9.81 m/s²), h = height (m)
GE= 3 x 9.81 x 2
GE = 58.86 J
Hope this helps
The earth makes one complete revolution around the sun in 365.24 days. Assuming that the orbit of the earth is circular and has a radius of 93,000,000 mi, determine the speedand magnitude of the acceleration of the earth, while treating earth as a point particle.[Hint: you can find the angular speed]Please be consistent with the units.
Answer:
The magnitudes of the speed and acceleration of the Earth are approximately 66,661.217 miles per hour and 47.782 miles per square hour, respectively.
Explanation:
Given that the Earth has a circular orbit and make a revolution at constant speed around the Sun. Then, the kinematic formulas for the speed and acceleration of the planet are, respectively:
Speed
[tex]v = \frac{2\pi\cdot R}{T}[/tex] (1)
Acceleration
[tex]a = \frac{4\pi^{2}\cdot R}{T^{2}}[/tex] (2)
Where:
[tex]v[/tex] - Speed of the planet, measured in miles per hour.
[tex]a[/tex] - Acceleration of the planet, measured in miles per square hour.
[tex]R[/tex] - Radius of the orbit, measured in miles.
[tex]T[/tex] - Period of rotation, measured in hours.
If we know that [tex]R = 93,000,000\,mi[/tex] and [tex]T = 8,765.76\,h[/tex], then the magnitudes of the speed and acceleration of the planet is:
[tex]v = \frac{2\pi\cdot (93,000,000\,mi)}{8,765.76\,h}[/tex]
[tex]v \approx 66,661.217\,\frac{mi}{h}[/tex]
[tex]a = \frac{4\pi^{2}\cdot (93,000,000\,mi)}{(8,765.76\,h)^{2}}[/tex]
[tex]a\approx 47.782\,\frac{mi}{h^{2}}[/tex]
The magnitudes of the speed and acceleration of the Earth are approximately 66,661.217 miles per hour and 47.782 miles per square hour, respectively.
An asteroid has acquired a net negative charge of 149 C from being bombarded by the solar wind over the years, and is currently in equilibrium whereby it expels electrons at the same rate as it acquires them. How many more electrons does it have than protons
Answer:
93.125 × 10^(19)
Explanation:
We are told the asteroid has acquired a net negative charge of 149 C.
Thus;
Q = -149 C
charge on electron has a value of:
e = -1.6 × 10^(-19) C
Now, for us to determine the excess electrons on the asteroid, we will just divide the net charge in excess on the asteroid by the charge of a single electron.
Thus;
n = Q/e
n = -149/(-1.6 × 10^(-19))
n = 93.125 × 10^(19)
Thus, it has 93.125 × 10^(19) more electrons than protons
Compare the weight of a 60 kg person on the earth with the weight of the same person on
the moon. Then, describe a quick (but very costly) way for dieters
at NASA to lose weight.
Answer:
Explanation:
The formula for weight is
W = mg, where
W = the weight of the object or person
m = mass of the object or person
g = acceleration due to gravity
Now, we're given the mass of the person to be 60 kd, and thus, the weight of that person would be
W = 60 * 9.81
W = 588.6 N
On the surface of the moon, the weight of the person would be
W = 60 * 1.625
W = 97.5 N
Therefore, the weight of the person on both surfaces are 588.6 and 97.5 respectively
Car 1 drives 20 mph to the south, and car 2 drives 30 mph to the north. From
the frame of reference of car 1, what is the velocity of car 2?
Answer:
10 mph faster than car 1 is going
Explanation:
It is difficult to lift a bigger stone than the smaller
stone. why?
plzzz give me short and brillient answer
In order for convection to transfer heat, particles need to
Select one:
a.
absorb solar and fossil energy
b.
circulate and move within a liquid or gas
c.
make contact with the heat source
d.
transmit electromagnetic waves
Answer:
the answer is b mark me as the brqinlist
During an isothermal process one mole of a monoatomic gas did 3000 J of work on its surrounding. The final volume and pressure of the gas are 25 L and 1 atm, respectively. What was the initial volume of the gas
Answer: The initial volume of the gas is 7.72 L
Explanation:
For an isothermal process the temperature is constant.
[tex]PV=nRT[/tex]
as P = pressure = 1 atm ,
V = Volume = 25 L
n = moles
R= gas constant
T = temperature
[tex]PV=1atm\times 25L[/tex]
[tex]nRT=25Latm=25\times 101.3J=2532.5J[/tex] (1Latm=101.3 J)
For isothermal reaction :
[tex]w=-2.303nRT\log\frac{V_2}{V_1}[/tex]
where , w = work done by system = -ve
n = moles = 1
[tex]V_2[/tex] = final volume = 25 L
[tex]V_1[/tex] = initial volume = ?
[tex]-3000J=-2.303\times 2532.5\log \frac{25}{V_1}[/tex]
[tex]V_1=7.72L[/tex]
Thus initial volume of the gas is 7.72 L
How would taping a coin to the balloon affect the overall motion of the balloon?
Answer:
the motion of the coin taping the balloon is the balloon squshing down
A toy car weighing 3.2 N gets pushed a distance of 10 m in 1.3 s. What is the momentum of the car?
Answer:
2.51 kg * m/s
Explanation:
In order to find momentum, use the equation below:
momentum = mass * velocity.
Since neither mass nor velocity was given, you must solve for both variables.
In order to solve for mass, use the force equation for its weight / gravitational force.
Fg (gravitational force) = 3.2 N = ma = 9.8m
mass = 3.2 N / 9.8 m/s^2 = 0.326531 kg
In order to solve for velocity, use the equation:
velocity = displacement / time
velocity = 10m / 1.3 s = 7.69231 m/s
Momentum = mass * velocity = 0.326531 kg * 7.69231 m/s = 2.51177 kg * m/s = 2.51 kg * m/s
Define each of the three heat transfer methods:
Conduction
Convection
Radiation
Which of the following is the best example of Newton’s third law? A. A person riding a bike at a constant speed B. A car accelerating C. Rowing a boat D. An orange rolling off a tray
Answer:
C; Rowing a boat
Explanation:
Hope this helps! :3
Plz mark as brainliest!
Thermal expansion of a gas causes a change in the ____ of the gas.
A. Radioactiveness
B. Density
C. Mass
D. Altitude
Answer:
B. Density
Explanation:
Thermal expansion of a gas will cause a definite change in the density of the gas.
It is product of an increase in the average kinetic energy of the system in which molecules are found.
Gaseous thermal expansion will increase the volume in which gases occupy. Mass of the gas will still remain the same. Since density is the mass per unit volume, as the gases expand, their density reduces more and more.Therefore, thermal expansion of gas will cause a change in the density of the gas.
What happens between particles of different charges?
Answer:
Oppositely charged objects will exert an attractive influence upon each other. In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other.
Explanation:
what belongs in the center section
Answer:
The second one I think
Explanation:
B
differentiate between capital g and small g
Answer:
Capital (G) is a universal gravitation law. and small (g) is acceleration of gravity of the each (9.8m/s^2)
Explanation:
According to the web
Question 4(Multiple Choice Worth 2 points)
Satellite technology has allowed us to monitor areas that were once so remote that we had no way of monitoring them. Review the statements and choose the one that best describes how we can use this technology to benefit the environment.
Large ocean liners use satellites to aid in navigation. This type of navigation aid is also used on cruise ships. Using satellites can help these large ships navigate waters during bad storms.
Satellite surveillance can be used to aid in port security. Satellite data can be monitored and evaluated by complex computer systems. These systems can alert officials when something unusual occurs.
Satellite technology allows us to monitor and track the changes in the polar ice sheets. This can help us plan and direct conservation efforts for the animals that depend on polar ice in order to survive.
Satellite surveillance has allowed us to map areas that were previously too remote to observe. This helps developers to locate and choose sites for large resorts.
Answer:
satellite technology helped large ocean liners guide you to our space mission.
Explanation:
Large ocean liners use satellites to aid in navigation. This type of navigation aid is also used on cruise ships. Using satellites can help these large ships navigate waters during bad storms.
Satellite surveillance can be used to aid in port security. Satellite data can be monitored and evaluated by complex computer systems. These systems can alert officials when something unusual occurs.
Satellite technology allows us to monitor and track the changes in the polar ice sheets. This can help us plan and direct conservation efforts for the animals that depend on polar ice in order to survive.
Satellite surveillance has allowed us to map areas that were previously too remote to observe. This helps developers to locate and choose sites for large resorts.
how many molecules of o2 are in 8.0 g of oxygen?if the o2 molecules were completely split into 9,how many mole of atoms of oxygen would be obtained?
How original were Newton’s contributions to science? (In what ways did Newton depend on the mechanical view?)
A ball is thrown with a speed of 100 ft/s in a direction of 30 degrees above the horizontal. determine the horizontal distance in m, the time of flight, and the height to which it rises..Note: you have to label your answer and final answer must be two decimal place
Answer:
Horizontal distance covered is 270.63ft
Time of flight is 3.125secs
Height to which it rises is 39.06feet
Explanation:
The horizontal distance covered is the range;
Range = U²sin2theta/g
Range = 100²sin2(30)/32
Range = 10000sin60/32
Range = 10000(0.8660)/32
Range = 8660/32
Range = 270.625ft
Hence the horizontal distance covered is 270.63ft
The time of flight is expressed using the formula;
T = 2Usin theta/g
g is the acceleration due to gravity
T = 2(100)sin30/32
T = 200(0.5)/32
T = 100/32
T = 3.125secs
Hence the time of flight is 3.125secs
Maximum height H = u²sin²theta/2g
H = 100²(sin30)²/2(32)
H = 10000(0.5²)/64
H = 10000(0.25)/64
H = 2500/64
H = 39.0625
Hence the height to which it rises is 39.06feet
Including them, the mass of the balloon was 1890 kg and had a volume of 11,430 m3 . The balloon floats at a constant height of 6.25m above the ground. What is the density of the hot air in the balloon
Given :
The mass of the balloon was 1890 kg and had a volume of 11,430 m3 .
The balloon floats at a constant height of 6.25m above the ground.
To Find :
The density of the hot air in the balloon.
Solution :
We know,
Volume × ( Density of surrounding air - Density of hot air ) = mass
Putting given values in above equation, we get :
[tex]11430\times ( 1.29 - \rho_{hot \ air } ) = 1890\\\\\rho_{hot \ air } = 1.29 - \dfrac{1890}{11430}\\\\\rho_{hot \ air } = 1.125\ kg\ m^3[/tex]
Therefore, the density of hot air in the balloon is 1.125 kg m³.
A child pulls a sled up a snow covered hill. If the child does 504J of work on the sled while pulling the sled 23m up the hill then how much force did they exert?
Explanation:
ans is equal to 504j* 23 m* 10 ms
A space probe is fired as a projectile from the Earth's surface with an initial speed of 2.05 104 m/s. What will its speed be when it is very far from the Earth
Answer:
The value is [tex]v = 2.3359 *10^{4} \ m/s[/tex]
Explanation:
From the question we are told that
The initial speed is [tex]u = 2.05 *10^{4} \ m/s[/tex]
Generally the total energy possessed by the space probe when on earth is mathematically represented as
[tex]T__{E}} = KE__{i}} + KE__{e}}[/tex]
Here [tex]KE_i[/tex] is the kinetic energy of the space probe due to its initial speed which is mathematically represented as
[tex]KE_i = \frac{1}{2} * m * u^2[/tex]
=> [tex]KE_i = \frac{1}{2} * m * (2.05 *10^{4})^2[/tex]
=> [tex]KE_i = 2.101 *10^{8} \ \ m \ \ J[/tex]
And [tex]KE_e[/tex] is the kinetic energy that the space probe requires to escape the Earth's gravitational pull , this is mathematically represented as
[tex]KE_e = \frac{1}{2} * m * v_e^2[/tex]
Here [tex]v_e[/tex] is the escape velocity from earth which has a value [tex]v_e = 11.2 *10^{3} \ m/s[/tex]
=> [tex]KE_e = \frac{1}{2} * m * (11.3 *10^{3})^2[/tex]
=> [tex]KE_e = 6.272 *10^{7} \ \ m \ \ J[/tex]
Generally given that at a position that is very far from the earth that the is Zero, the kinetic energy at that position is mathematically represented as
[tex]KE_p = \frac{1}{2} * m * v^2[/tex]
Generally from the law energy conservation we have that
[tex]T__{E}} = KE_p[/tex]
So
[tex]2.101 *10^{8} m + 6.272 *10^{7} m = \frac{1}{2} * m * v^2[/tex]
=> [tex]5.4564 *10^{8} = v^2[/tex]
=> [tex]v = \sqrt{5.4564 *10^{8}}[/tex]
=> [tex]v = 2.3359 *10^{4} \ m/s[/tex]
At what angle should the roadway on a curve with a 50-m radius be banked to allow cars to negotiate the curve at 12 m/s even if the roadway is icy (and the frictional force is zero)
Answer:
The value is [tex]\theta = 16.38^o[/tex]
Explanation:
From the question we are told that
The radius is [tex]r = 50 \ m[/tex]
The velocity is [tex]v = 12 \ m/s[/tex]
Generally the angle is mathematically represented as
[tex]\theta = tan^{-1} [\frac{v^2}{ gr} ][/tex]
=> [tex]\theta = tan^{-1} [\frac{12^2}{ 9.8 * 50 } ][/tex]
=> [tex]\theta = tan^{-1} [ 0.2939 ][/tex]
=> [tex]\theta = 16.38^o[/tex]
To celebrate a victory, a pitcher throws her glove straight upward with an initial speed of 5.3 m/s. How long does it take for the glove to reach its maximum height
Hello!!
For the maximum height the final velocity is zero, because can't up more.
Then, use the formula:
V = Vi + gt
Replacing, we have:
0 m/s = 5,3 m/s + (-9,8 m/s² * t)
0 m/s - 5,3 m/s = -9,8 m/s² * t
(-5,3 m/s) / -9,8 m/s² = t
t = 0,54 s
The time it will take to reach the maximum height is 0,54 seconds.
Nuclear power plants produce energy using:________
a. nuclear fission.
b. nuclear fusion.
c. combustion.
d. critical mass.
Answer: a. nuclear fission.
Explanation:
Nuclear power plants use heavy materials, like uranium 238, which is bombarded with neutrons. When the neutrons interact with the uranium, there is fission (a division of one atom into smaller ones and other subatomic particles), and in this process, more neutrons are produced. These new neutrons may impact other atoms of uranium and continue with this cycle, generating heat in the process.
Then we can conclude that nuclear power plants produce energy using nuclear fission.
If a man has
a mass of 115 pounds what what is his mass in gram
Answer:
52,163.1
Explanation:
A spanner is an example of:
i. screw ii. wheel and axle
iii. pulley
iv. wedge
formula
Answer:
The answer is "wedge"
Explanation:
A wedge is an item that tightens to a meager edge. Pushing the wedge one direction makes a force in a sideways direction. It is normally made of metal or wood and is used for parting, tightening, lifting, or fixing, as in making sure about a hammer head onto its handle.
The wedge was used in ancient occasions to part logs and shakes; an ax is also a wedge, similar to the teeth on a saw. As far as its mechanical capacity, the screw might be considered as a wedge folded over a cylinder.