Answer:
1.47 s
Explanation:
From the question,
s = 2d/t................... Equation 1
s = speed of sound in air, d = distance between the boy and the hill, t = time to hear the echo.
make t the subject of the equation
t = 2d/s............... Equation 2
Given: d = 250 meters
Constant: s = 340 m/s
Substitute these values into equation 2
t = (2×250)/340
t = 500/340
t = 1.47 s
What would happen if we do not eat body building food?
Answer:
you would die and be dead.....
Explanation:
Answer:
You may suffer from muscle weakness.
If you want to build muscles, protein is the way to go.
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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Two charges are separated by a distance r. The distance between the charges is tripled to 3r. If the original force between the charges was 45N what is the new force between the charges A.5N B.15N C.75N D.135N
Answer:
5N
Explanation:
The formula formula for calculating the force between charges is expressed as;
F = kq1q2/r²
If two charges are separated by a distance r and a force between them is 45N, then;
45 = kq1q2/r² ....1
If the distance between the charges is tripled to 3r, then;
F = kq1q2/(3r)²
F = kq1q2/9r² ... 2
Divide both expressions
45/F = (kq1q2/r²)/(kq1q2/9r²)
45/F = kq1q2/r² * 9r²/kq1q2
45/F = 9
9F = 45
F = 45/9
F = 5N
Hence the new force between them will be 5N
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.
What is a voltage divider?
Answer:
please give me brainlist and follow
Explanation:
In electronics, a voltage divider (also known as a potential divider) is a passive linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). Voltage division is the result of distributing the input voltage among the components of the divider.
Suppose you are working on green house, which light you would
use for their growth?
Answer:
Fluorescent lighting is usually used.
Explanation:
Answer:
HPS lighting or LED light
Explanation:
HPS light is well known choice with a proven track record for growers. While you can also use LED lights as an alternative to incandescent or HPS fixtures for day length extension.
Although not all snakes are poisonous, all snakes may carry what infection?
a
Rabies
b
Polio
c
Tetanus (or Lockjaw)
d
Lyme's disease
Answer:
C
Explanation:
Not A because mammals cant get rabies. Defenently not polio. I think C is the best answer. Lyme disease is caused by ticks, so no.
A laser pulse of duration 25 ms has a total energy of 1.4 J. The wavelength of this radiation is
567 nm. How many photons are emitted in one pulse? Let 1 eV = 1.60 x 10-19 J, the mass of
an electron m=9.11 10-31
kg, the speed of light c= 3.00 x 108 m/s, and Planck's constant h
= 4.136 10-15 eV .s.
Answer:
n = 4 x 10¹⁸ photons
Explanation:
First, we will calculate the energy of one photon in the radiation:
[tex]E = \frac{hc}{\lambda}\\\\[/tex]
where,
E = Energy of one photon = ?
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of radiation = 567 nm = 5.67 x 10⁻⁷ m
Therefore,
[tex]E = \frac{(6.625\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{5.67\ x\ 10^{-7}\ m}[/tex]
E = 3.505 x 10⁻¹⁹ J
Now, the number of photons to make up the total energy can be calculated as follows:
[tex]Total\ Energy = nE\\1.4\ J = n(3.505\ x\ 10^{-19}\ J)\\n = \frac{1.4\ J}{3.505\ x\ 10^{-19}\ J}\\[/tex]
n = 4 x 10¹⁸ photons
Write any two uses of simple machines.
How old is Earth and what do we use to keep track of major Earth events?
A plumber is going to put two pipes in a wall, one in front and one in back. The pipes will be touching once they are installed. Both pipes are the same size and have the same number of molecules. The diagram above shows the pipes now, before they have touched. Use the information in the diagram to answer the question.
How does the temperature of the front pipe compare with the temperature of the back pipe before the pipes touch? What will happen after the pipes have been touching for a while?
Answer:
They become the same exact tempature
Explanation:
Since they got connected it should be the same.
the temperature of the front pipe compare with the temperature of the back pipe before the pipes touch by using same temperature.
what is temperature ?Temperature is the measure of hotness or coldness expressed in terms of any of several arbitrary scales and it indicate the direction in which heat energy will spontaneously flow from a hotter body to a colder body.
It is not the equivalent of the energy of a thermodynamic system like burning match is at a much higher temperature than an iceberg whereas the total heat energy contained in an iceberg.
Temperature which is similar to pressure or density known as intensive property that is independent of the quantity of matter is considered as distinguished from extensive properties, such as mass or volume.
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Which object is an example of a mechanical wave?
A. light from a flashlight
B. microwaves used to heat food
C. police siren
D. sunlight
Answer:
C.
Explanation:
Hope It Helps
brainliest please
Answer:
C. police siren
Explanation:
Sound waves are mechanical waves
A uniform electric field, with a magnitude of 449 N/C, is directed parallel to the positive x-axis. If the potential at x= 4.59 m is 966 V, what is the potential at x= 1.61 m?
Answer:
2.334 kV
Explanation:
Since the electric field strength Ecosθ = -ΔV/Δx = -(V₂ - V₁)/(x₂ - x₁)
where V₁ = potential at x₁ = 966 V, x₁ = 4.59 m, V₂ = potential at x₂ = unknown, x₂ = 1.61 m and θ = angle between E and the x - axis.
Given that E = + 449 N/C and since it is directed parallel to the positive x - axis, θ = 0°
So,
Ecosθ = -ΔV/Δx
Ecos0° = -ΔV/Δx
E = -ΔV/Δx
E = -(V₂ - V₁)/(x₂ - x₁)
making V₂ subject of the formula, we have
-E(x₂ - x₁) = V₂ - V₁
-E(x₂ - x₁) + V₁ = V₂
V₂ = V₁ - E(x₂ - x₁)
Substituting the values of the variables into the equation, we have
V₂ = V₁ - E(x₂ - x₁)
V₂ = 966 V - 449 N/C(1.61 m - 4.59 m)
V₂ = 966 V - 449 N/C(-2.98 m)
V₂ = 966 V + 1,338.02 Nm/C
V₂ = 966 V + 1,338.02 V
V₂ = 2,334.02 V
V₂ ≅ 2,334 V
V₂ = 2.334 kV
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
1. An object of mass 300 kg is observed to
accelerate at the rate of 1 m/s. Calalate the
force required to produce this acceleration.
Answer:
The force required will be "300 N".
Explanation:
The given values are:
Mass of object,
m = 300 kg
Acceleration,
a = 1 m/s
Now,
The force will be:
⇒ [tex]F=m\times a[/tex]
On substituting the values, we get
⇒ [tex]= 300\times 1[/tex]
⇒ [tex]=300 \ N[/tex]
A 42.2 N force acts at 40* to the ground, causing the object to move a horizontal distance of 8.15 m. How much work was done on the object?
Answer:
W=F.dcos angle
w=42.2 x8.15 x cos40
w=343.93× cos 40
W=343.93 x 0.76
W=261.38 J
Work done on the object will be 264.83 J
What is work done ?Work done is the product of the component of the force in the direction of the displacement and the magnitude of this displacement.
given :
F = 42.2 N
let , x = 40°
horizontal distance (s) = 8.15 m
Work done = F s cos (x)
= F * s * cos (x)
= 42.2 * 8.15 * cos 40° = .766
= 343.93 * 0.77
= 264.83 J
Work done on the object will be 264.83 J
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Four different living organisms are shown on the right. Which statement is true for all of the organisms shown?
Answer:
they are all made of cells
How would the motion of the book change if there was LESS friction as it moved across the table?
Answer:
The motion of the book would change if there was less friction if it moved across the table is that it would spin and have more kenetic energy.
Explanation:
friction slows stuff down so if it had less friction it would speed up and spin when sliding.
How will the boat be affected if it enters a part of the river where the current is moving south at 2 m/s?
Answer:
The boat is most likely to crash or sink since the water will be very rapid and pacing.
given a force of 100 N and a acceleration of 5 m/s, what is the mass
Answer:
[tex]force = mass \times acceleration \\ 100 = m \times 5 \\ m = \frac{100}{5} \\ m = 20 \: kg[/tex]
Can anyone help me with this question please
I’ll mark as brainliest
No links.
the transverse Wave which is Answer:2
Answer:
1
Explanation:
amplitude is the maximum distance from the rest of the particles. amplitude is thus measured from the rest position to the peak of a crest or of a trough.
as seen below, graph 1 has an amplitude of 1 while both graph 2 and 3 has an amplitude of 2.
Which is a pollutant associated with high-tech gadgets in landfills?
A. Chromium
B. Steel
C. Carbon Dioxide
D. Hydrogen
Answer:
The answer of this is question is A.
Answer:
A.
Explanation:
sana makatulong po ❤❤
I'm stuck between B and C
In the problem, I know the potential energy increases because the height increases.
A block is at the bottom of a frictionless ramp and is given a kick so that it has some initial velocity and starts to slide up the ramp. There
is no air resistance. Which of the following is true of the energy of the block as it slides?
(A) Its potential energy will increase; its kinetic energy will decrease.
(C) Both its potential and kinetic energies will increase.
(B) Its potential energy will decrease; its kinetic energy will increase.
(D) Both its potential and kinetic energies will decrease.
Answer:
Explanation:
The answer is A. First of all, due to the First Law of Thermodynamics, energy cannot be created or destroyed, it only changes form. That being said, it is impossible for the PE and the KE to both increase or decrease at the same time. The second one starts decreasing, the other starts increasing at the exact same rate. PE exists or is at its highest when an object has the potential to fall to a point lower than it is, and it is at this point where Kinetic energy is the lowest. If this block is kicked UP a ramp, which is odd but there you have it, the potential energy increases as it gets higher off the ground. Because of gravity, and assuming that once the block is kicked, the foot that kicked it is no longer important to it (meaning it's not being pushed up, it's just kicked once and that's it) and it will slow down very quickly. KE exists where there is a great amount of velocity.
The answer is A.
what is a magnetic field? how could you visualize one?
Answer:
A magnetic field is what causes gravity basically
Explanation:
To visualize a magnetic field think of 2 ovals on the opposite side of each-other, like one oval on the top of a circle and one on the bottom, that's how id visualize it
An incident ray that passes through the vertex of a convex lens:
F
F
c
A. refracts inward, at an angle equal to the angle of incidence,
B. continues in a straight line without refracting.
C. refracts parallel to the axis of the lens,
D. refracts outward, at an angle equal to the angle of incidence.
why is a screw a kind of inclined plane
Explain why sounds are fainter at high mountains than sea level
Describe the role that weathering and erosion play in the rock cycle.
Answer:
Weathering is the breaking down or dissolving of rocks and minerals on Earths surface. Once a rock has been broken down, a process called erosion transports the bits of rock and minerals away. Water, acids, salt, plants, animals, and changes in temperature are all agents of weathering and erosion.
plz can i get brainliest
) The unsaturated hydrocarbons whose structures contain a carbon -carbon triple
bond are called ……..
a) Alkenes b) Alkanes c) Alkynes d) Alcohol
Answer:
C. Alkynes
Explanation:
Why are solar storms a concern to Earth?