Answer:
a. 13.7 s b. 6913.5 m
Explanation:
a. How much time before being directly overhead should the box be dropped?
Since the box falls under gravity we use the equation
y = ut - 1/2gt² where y = height of plane above ocean = 919 m, u = initial vertical velocity of airplane = 0 m/s, g = acceleration due to gravity = -9.8 m/s² and t = time it takes the airplane to be directly overhead.
So,
y = ut - 1/2gt²
y = 0 × t - 1/2gt²
y = 0 - 1/2gt²
y = - 1/2gt²
t² = -2y/g
t = √(-2y/g)
So, t = √(-2 × 919 m/-9.8 m/s²)
t = √(-1838 m/-9.8 m/s²)
t = √(187.551 m²/s²)
t = 13.69 s
t ≅ 13.7 s
So, the box should be dropped 13.69 s before being directly overhead.
b. What is the horizontal distance between the plane and the victims when the box is dropped?
The horizontal distance x between plane and victims, x = speed of plane × time it takes for box to drop = 505 m/s × 13.69 s = 6913.45 m ≅ 6913.5 m
What percentage of the starting matter in our solar system went into the formation of our sun?
Answer:
Eventually the pressure in the core was so great that hydrogen atoms began to combine and form helium, releasing a tremendous amount of energy. With that, our Sun was born, and it eventually amassed more than 99 percent of the available matter
What happens when an object is moved against gravity, such as rolling a toy car up a ramp?
Answer:
it goes up until we help it to but the moment we stop support it gets affected by gravity and goes back
Explanation:
A small cork with an excess charge of +6.0 μC (1 μC = 10 -6 C) is placed 0.12 m from another cork, which carries a charge of -4.3 μC. a. What is the magnitude of the electric force between the corks? b. Is this force attractive or repulsive? c. How many excess electrons are on the negative cork? d. How many electrons has the positive cork lost?
Answer:
a.16.125 N b. The force is an attractive force. c. 2.68 × 10¹³ electrons d. 3.75 × 10¹³ electrons
Explanation:
a. What is the magnitude of the electric force between the corks?
The electrostatic force of attraction between the two corks is given by
F = kq₁q₂/r² where k = 9 × 10⁹ Nm²/C², q₁ = +6.0 μC = +6.0 × 10⁻⁶ C, q₂ = -4.3 μC = -4.3 × 10⁻⁶ C and r = distance between the corks = 0.12 m
Substituting the values of the variables into the equation, we have
F = kq₁q₂/r²
F = 9 × 10⁹ Nm²/C² × +6.0 × 10⁻⁶ C × -4.3 × 10⁻⁶ C/(0.12 m)²
= -232.2 × 10⁻³ Nm²/(0.0144 m)²
= -16125 × 10⁻³ N
= -16.125 N
So, the magnitude of the force is 16.125 N
b. Is this force attractive or repulsive?
Since the direction of the force is negative, it is directed towards the positively charged cork, so the force is an attractive force.
c. How many excess electrons are on the negative cork?
Since Q = ne where Q = charge on negative cork = -4.3 μC = -4.3 × 10⁻⁶ C and n = number of excess electrons and e = electron charge = -1.602 × 10⁻¹⁹ C
So n = Q/e = -4.3 × 10⁻⁶ C/-1.602 × 10⁻¹⁹ C = 2.68 × 10¹³ electrons
d. How many electrons has the positive cork lost?
We need to first find the number of excess positive charge n'
Q' = n'q where Q = charge on positive cork = + 6.0 μC = + 6.0 × 10⁻⁶ C and n = number of excess protons and q = proton charge = +1.602 × 10⁻¹⁹ C
So n' = Q'/q = +6.0 × 10⁻⁶ C/+1.602 × 10⁻¹⁹ C = 3.75 × 10¹³ protons
To maintain a positive charge, the number of excess protons equals the number of electrons lost = 3.75 × 10¹³ electrons
an airplane has a maximum velocity of 160km/h in still air. calculate its maximum velocity when it travels in air with a crosswind of 30km/h
Answer:
Velocity can be directly added or subtracted.
For example, if a boat has a velocity V in still water.
And now you put the boat in a river with a current that has a velocity V'
The total velocity of the boat in that river is just the addition of these two velocities.
Velocity in the river = V + V'
Where the only tricky part is that the velocity is a vector, so you need to take in account the directions of each vector.
In this case, we have a plane with a maximum velocity of 160km, let's assume a direction for this velocity, let's say that is in the positive x-direction.
Then we can write the velocity in the vector form:
velocity = (vel in x-axis, vel in y-axis)
The velocity of the plane can be written as:
v = (160km/h, 0)
Now we add a crosswind of 30km/h
crosswind means that it is perpendicular, then it acts on the y-axis.
Then the total velocity of the plane will be:
velocity = (160km/h, 0) + (0, 30km/h)
velocity = (160km/h, 30km/h)
Now you can compute the total velocity of the airplane as the module of that vector.
Remember that for a vector (x, y) the module is:
mod = √(x^2 + y^2)
Then the module of the velocity is:
v = √( (160km/h)^2 + (30km/h)^2) = 162.8 km/h
What process do scientists think is causing the movement of Earth’s tectonic plates? Name one other place where this process is occurring naturally.
Answer:
convection currents in the earth's mantle, heat and pressure within the earth cause the hot magma to flow in convection currents. This causes the movement of the tectonic plates.
rift valley, Africa
plz mark me as brainliest
A 100 watt bulb with 60 volts has a current flow of how many Amps?
Answer:
I = 1.666... amps
Explanation:
P = I*V or Power = Current * Voltage
(100 watts) = I * (60 Volts)
I = 1.666... amps
A tuning fork vibrating in water with a frequency of 840 Hz produces waves that are 2.5 m long. If a tuning fork vibrating at 500 Hz produces the same type of wave in water, what will the wavelength of the waves be?
A) 1.5 m
B) 4.2 m
C) 3.2 m
D) 2.5 m
Answer:
Option B
Explanation:
As we know
Frequency (F) * wavelength (W) = C (speed of light - can also be taken as constant)
Hence,
[tex]F1 W1 = C\\F2W2 = C[/tex]
Or [tex]F1W1 = F2W2[/tex]
Substituting the given values, we get -
[tex]840 *2.5 = 500 *XX = 4.2[/tex] m
Hence, option B is correct
state two other ways in which evaporation is different from boiling
A police car is driving north with a siren making a frequency of 1038 hz. Moops is driving north behind the police car at 12 m/s and hard a frequency of 959hz. How fast is the police car going?
Answer:
The police car is moving at 41.24 m/s.
Explanation:
To find the speed of the police car we need to use the Doppler equation:
[tex] f = f_{0}(\frac{v + v_{r}}{v + v_{s}}) [/tex]
Where:
v: is the speed of the sound = 343 m/s
[tex]v_{r}[/tex]: is the speed of the receiver = 12 m/s
[tex]v_{s}[/tex]: is the speed of the source =?
f: is the observed frequency = 959 Hz
f₀: is the emitted frequency = 1038 Hz
Both terms are positive in the fraction because the velocity of the sound is in the opposite direction to both velocities of the police car and the other car.
By solving the above equation for [tex]v_{s}[/tex] we have:
[tex] v_{s} = \frac{f_{0}(v + v_{r})}{f} - v = \frac{1038(343 + 12)}{959} - 343 = 41.24 m/s [/tex]
Therefore, the police car is moving at 41.24 m/s.
I hope it helps you!
The smallest molecules are made up of -
a. 1 atom
b. 2 atoms
c. 3 atoms
The largest molecules are made up of -
a. billions
b. millions
c. hundreds
d. thousands
- of atoms.
What makes water a natural resource?
A.
It is a natural material that can be easily replaced.
B.
It is a material found in nature that people can use.
C.
It is a material that people can easily make and use.
D.
It is a energy source that cannot be replaced.
Answer:
I belive is the answer is B. It is a material found in nature that people can use. Because water is technically a natural resource.
An electron and a proton are both released from rest, midway between the plates of a charged parallel-plate capacitor. The only force on each of the two particles is the force from the uniform electric field due to the capacitor. Each particle accelerates until striking one of the plates of the capacitor. (There is no gravity in this problem and we ignore the small force between the electron and the proton.) How do the final kinetic energies and final speeds (just before striking a plate) compare
Answer:
Explanation:
Let the potential difference between the middle point and one of the plate be ΔV .
electric potential energy will be lost and it will be converted into kinetic energy .
Electrical potential energy lost = Vq , where q is charge on charge particle .
For proton
ΔV× q = 1/2 M V² ( kinetic energy of proton )
where M is mass and V be final velocity of proton .
For electron
ΔV× q = 1/2 m v² ( kinetic energy of electron )
where m is mass and v be final velocity of electron . Charges on proton and electron are same in magnitude .
As LHS of both the equation are same , RHS will also be same . That means the kinetic energy of both proton and electron will be same
1/2 M V² = 1/2 m v²
(V / v )² = ( m / M )
(V / v ) = √ ( m / M )
In other words , their velocities are inversely proportional to square root of their masses .
A 5000kg elephant steps into a large spring and compresses it from 1m long to 50cm long what is the spring constant of the spring
Answer: 98 kN/m
Explanation:
Given
Mass of elephant [tex]m=5000\ kg[/tex]
Spring compresses from [tex]1\ m\ (100\ cm) \text{to}\ 50\ cm[/tex]
i.e. change in length is [tex]100-50=50\ cm[/tex]
spring force is given by [tex]kx[/tex]
where k=spring constant
x=change in length
The weight of elephant must be equal to the spring force
[tex]\Rightarrow W=kx\\\Rightarrow 5000\times 9.8=k\times 0.5\\\Rightarrow k=98,000\ N/m\ or\ 98\ kN/m[/tex]
In this reaction, how many miles of CO2 would be produced when methane (CH4) fully reacts with 6 moles of O2? CH4 + 2O2 - 2H2O + CO2
Answer:
3 moles
Explanation:
Ratio of O2 to CO2 = 2 : 1 = 6 : 3
What unit is kinetic energy measured in?
Explanation:
jouleeeee is the unit kinetic energy is measured in and kinetic energy formula is 1/2mv (square)
Which of the following processes is most likely to have smaller atomic nuclei
as reactants?
Answer:
It would be B.
Explanation:
Question:
(need answers now I have time)
A freely-falling object is accelerating.
A. True
B. False
Answer:
the answer is true.
Explanation:
hope it will help you
Eee A student conducts an investigation to determine how the force of gravity affects different objects dropped from different heights. The student tests each object one time and announces that all objects experienced gravity the same way. What is wrong with the student's reasoning?
Answer:
For which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.
Explanation:
The force of gravity comes from Newton's second law with the force the universal attraction
F = ma
F = [tex]G \frac{m_1 M}{(R_e +h)^2}[/tex]
we substitute
[tex]G \frac{m_1 M}{ (R_e+ h)^2}[/tex] = m₁ a
where Re is the radius of the Earth 6.37 106 m
a = [tex]G\frac{M}{R_e^2} \ ( 1 + \frac{h}{R_e})^{-2}[/tex]
In general, the height is much less than the radius of the earth, therefore the term ha / Re is very small and we can use a series expansion leaving only the first fears.
(1 + x)⁻² = 1 -2x + [tex]\frac{2 \ 1}{2!}[/tex] x²
we substitute
a = g₀ ([tex]1 - 2 \frac{h}{R_e}[/tex] )
with
g₀ = [tex]G \frac{M}{R_e^2}[/tex]
let's launch the expression.
* For small height compared to the radius of the earth we can neglect the last term
g = g₀
* For height comparable to the radius of the Earth
g = g₀ [tex](1 - \frac{2h}{Re} )[/tex]
We see that the acceleration of gravity is decreasing.
For which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.
The student's reasoning gone wrong when the analysis is undertaken for the increasing heights, to drop the object.
The given problem is based on the concept of gravity and gravitational force. The force of gravity comes from Newton's second law with the force the universal attraction as,
F = ma
[tex]F=G\dfrac{mM}{(R+h)^{2}}\\\\\\ma = G\dfrac{mM}{(R+h)^{2}}[/tex]
Here, a is the linear acceleration, m is the mass of object, M is the mass of Earth, R is the radius of Earth and h is the height from where the objects will be dropped. Then,
[tex]a = \dfrac{GM}{R^{2}} \times(1+h/R)^{-2}[/tex]
In general, the height is much less than the radius of the earth, therefore the term h/ R is very small, hence can be neglected.
[tex]a = \dfrac{GM}{R^{2}}\\\\a=g = \dfrac{GM}{R^{2}}[/tex]
g is the gravitational acceleration.
For small height compared to the radius of the earth we can neglect the last term as,
a = g
And for the height comparable to radius of Earth,
[tex]a = \dfrac{GM}{R^{2}} \times(1+h/R)^{-2}\\\\a=g \times(1+h/R)^{-2}[/tex]
Clearly, the acceleration of gravity is decreasing, for which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.
Thus, we can conclude that the student's reasoning gone wrong when the analysis is undertaken for the increasing heights, to drop the object.
Learn more about the gravitational force here:
https://brainly.com/question/15647838
define one kilogram mass
Answer:
a unit of mass or weight equaling one thousand grams
If an object possesses 500 J of potential energy, how much work is needed to lift this object?
a) 500 J
b) 250 J
c) 150 J
d) 1000 J
Answer:
a) 500 J
Explanation:
Potential energy can be defined as an energy possessed by an object or body due to its position.
Mathematically, potential energy is given by the formula;
[tex] P.E = mgh[/tex]
Where,
P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
In Science, the potential energy possessed by an object or body is the same as the work done by the object or body.
Since we know that the object possessed 500 Joules of potential energy; it would ultimately require to do a work of 500 Joules to lift the object.
Mathematically, work done = force * distance
But force = mass * acceleration due to gravity
F = mg; d = h
Substituting into the work done formula, we have;
Hence, Workdone = Fd = mgh
A motion sensor emits sound, and detects an echo 0.0115 s after. A short time later, it again emits a sound, and hears an echo after 0.0183 s. How far has the reflecting object moved? (Speed of sound = 343 m/s) (Unit = m)
Answer:
1.17 m
Explanation:
From the question,
s₁ = vt₁/2................ Equation 1
Where s₁ = distance of the reflecting object for the first echo, v = speed of the sound in air, t₁ = time to dectect the first echo.
Given: v = 343 m/s, t = 0.0115 s
Substitute into equation 1
s₁ = (343×0.0115)/2
s₁ = 1.97 m.
Similarly,
s₂ = vt₂/2.................. Equation 2
Where s₂ = distance of the reflecting object for the second echo, t₂ = Time taken to detect the second echo
Given: v = 343 m/s, t₂ = 0.0183 s
Substitute into equation 2
s₂ = (343×0.0183)/2
s₂ = 3.14 m
The distance moved by the reflecting object from s₁ to s₂ = s₂-s₁
s₂-s₁ = (3.14-1.97) m = 1.17 m
How does burning wood compare to the chemical reactions in trees that make them grow?
Answer:
Log burning in a fire. Burning wood is an example of a chemical reaction in which wood in the presence of heat and oxygen is transformed into carbon dioxide, water vapor, and ash.
Explanation:
Why do you fall forward when you stub your toe on a chair? Explain in terms.
Answer & Explanation:
This can be explained with Newton's first law, Inertia - if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
When you walk, your entire body is in a forwarding motion. If your toe hits an object (in this case, a chair), only this unfortunate toe will stop while the rest of your body continues its forwarding motion, resulting in you falling forward.
Both the terms immigration ("moving into a population") and emigration ("moving out of a population") come from the Latin word migrare ("to move"). What do you think the prefixes im- and e- mean?
Answer:
im means into
e means out of
Explanation:
Using the definitions of immigration and emigration as points of reference, the following explanation applies.
Both terms are derived from migration which means moving from one place to another.
By further explanation:
The "im" in the definition of immigration means "into" while the "e" in the definition of emigration means "out of"
A car travels 140 miles in 3 hours. What is its velocity?
Answer:
46.67 miles/s
Explanation:
...........
Who sponsored Felix Baumgartner in the second space jump that took placed in
2008?
Alban Geissler, who developed the SKYRAY carbon fiber wing with Christoph Aarns, suggested after Baumgartner's jump that the wing he used was a copy of two prototype SKYRAY wings sold to Red Bull (Baumgartner's sponsor) two years earlier. - wiki
The properties of being
a. clear and bright
b. useful and profitable
make a diamond a gemstone.
c. easy to obtain and beautiful
d. colorful and profitable
Answer:
D !!!
Explanation:
Answer:
D
Explanation:
Which is a property of every
mixture?
You have a 40-Hz sound wave and a 5,000-Hz sound wave. Both are traveling
through steel. Which sound wave will travel faster?
The waves will travel at the same speed as one another.
The 40-Hz wave will travel the fastest.
The 5,000-Hz wave will travel the fastest.
The louder of the two sound waves with travel the fastest.
Answer:
5,000-Hz
Explanation:
If water is flowing in a 1-inch diameter pipe with an average velocity of 3 m/s and the wall roughness is 400 microns, calculate the wall shear stress.
Answer:
Shear stress is 50.63 Pascal
Explanation:
As we know shear stress = [tex]\frac{\rho V^2 f}{8} \\[/tex]
Rho is the density
V is the velocity
f is the value from Moody's chart
We will know determine Reynolds number to determine the flow type and then the f value
[tex]R_e = \frac{ \rho*V*D}{u}[/tex]
[tex]R_e = \frac{1000*3*0.0254}{0.001} = 76200[/tex]
This is a turbulent flow and hence the roughness index is [tex]\frac{E}{D} = 0.0157[/tex], From this we get f = 0.045
Now shear stress = [tex]\frac{1000 * 3^2 * 0.045}{8} = 50.63[/tex] Pa