A car travelling at 30 ms' decelerates
to 10 m sin a distance of 20 m. What
is the deceleration of the motion, in m
s?
Answer:
V²=U² + 2as
Where V=Final Velocity
U=Initial Velocity
a=acceleration ( Deceleration in this case)
s=distance covered
10² = 30² + 2(a)(20)
100 = 900 + 40a
100 - 900 = 40a
-800=40a
a= -800/40
a= -20ms-².
Its negative because the car Decelerated.
A HIGH SPEED TRAIN IS 180M LONG AND IT IS TRAVELLING AT 50M/S.HOW LONG WILL IT TAKE TO PASS A PERSON STANDING AT A LEVEL CROSSING?
B-HOW LONG WILL IT TAKE TO PASS COMPLETELY THROUGH A STATION WHOSE PLATFORMS ARE 220M IN LENGTH?
Answer:
a. Time = 3.6 seconds
b. Time = 4.4 seconds
Explanation:
Given the following data;
Distance = 180 m
Speed = 50 m/s
a. To find the time;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
[tex]Speed = \frac{distance}{time}[/tex]
Making time the subject of formula, we have;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{180}{50}[/tex]
Time = 3.6 seconds
b. Distance = 220 meters
Speed = 50 m/s
To find the time;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{220}{50}[/tex]
Time = 4.4 seconds
Magnets are formed from iron, nickel, or cobalt when the ______________________ line up in the same direction.
Answer:
electrons
In substances such as iron, cobalt, and nickel, most of the electrons spin in the same direction. When you rub a piece of iron along a magnet, the north-seeking poles of the atoms in the iron line up in the same direction. The force generated by the aligned atoms creates a magnetic field, hence it acts as a magnet.
the materials that can be magnetized this way are called ferromagnetic materials, but it is not permanent and after some times it loses all the magnetic properties.
please if you find this answer helpful mark it as brainliest
Magnets are formed from iron, nickel, or cobalt when the electrons in their atoms' outer energy levels line up in the same direction that is present in Option A, as the alignment creates a magnetic field that can attract or repel other magnets or magnetic materials.
What are magnets?At the atomic level, electrons orbit the nucleus in shells or energy levels, and electrons have a property called spin, which creates a tiny magnetic field around them. Normally, electrons in an atom have random spin directions, so their magnetic fields cancel each other out and the atom has no overall magnetic field. In some materials, such as iron, nickel, and cobalt, the electrons in the outer energy level can line up in the same direction, creating a net magnetic field. This is known as ferromagnetism.
Hence, magnets are formed from iron, nickel, or cobalt when the electrons in their atoms' outer energy levels line up in the same direction that is present in Option A,
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question is incomplete, complete question is below
Magnets are formed from iron, nickel, or cobalt when the ______________________ line up in the same direction.
A)electrons in their atoms' outer energy levels
B)proton explodes
1) the wavelengths property that makes it possible for sound to be heard around a bend is A) diffraction. B) Reflection C) refraction. D) interference
2) which property of sounds do bats use to detect their paths?
A) Diffraction B) reflection C) Refraction D) interference
please give a reason or an explanation for each answer you choose
Answer:
1. A
2. B
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases.
Wavelength can be defined as the distance from one peak to the next peak of a waveform. This distance is also equal to the distance from one trough of a wave to another.
Diffraction is a wavelength property that makes it possible for sound to be heard around a bend. Thus, it's a property that causes a change in the direction of a wave as it travels through or around a barrier (obstacle) in its path.
Simply stated, diffraction involves the bending of waves around small obstacles with their dimensions smaller than or approximately equal to the wavelength of the sound wave.
On the other hand, reflection can be defined as a phenomenon which typically involves a change in the direction of a wave (bounces back) as it falls on a surface.
Hence, reflection is the property of sounds which animals such as bats use to detect their paths as they navigate from one point to another. This phenomenon is generally referred to as echolocation and it typically involves the use of reflection (echo) of sound to gain information about the nature and location of surrounding objects.
What is resistance? Difference between resistance and resistivity.
Answer:
Resistance is a measure of the opposition to current flow in an electrical circuit.All materials resist current flow to some degree. They fall into one of two broad categories: Conductors: Materials that offer very little resistance where electrons can move easily.
A car starts from rest. if rhe final velocity becomes 50m /s after 10 second calculate the acceleration of the car.
Answer:5m/s² well I am not pretty sure but hope it's help
Explanation:
u=0m
final velocity ,v=50m/s
t=10s
(v-u)/t=(50-0)/10=50/10=5m/s²
a student drops a ball off the top of building and records that the ball takes 3.32s to reach the ground (g=9.8 m/s^2). what is the ball's speed just before hitting the ground?
Answer:
Explanation:
Use the one-dimensional equation for motion
v = v₀ + at and filling in,
v = 0 + (-9.8)(3.32) so
v = -33 m/s (negative because it is going downwards and upwards is positive).
Which of the following refers to friction that acts on an object that is not moving? O A. Kinetic friction O B. Inertia O c. Contact force O D. Static friction
HELP PLEASE!!
Answer:
D.STATIC FRICTION
Explanation:
Have a nice day
A small bar magnet is placed in the magnetic field of a larger
bar magnet, at the position marked Zin the diagram below.
Assuming the small bar magnet is free to rotate, how would it
be positioned?
X
no
N
S
O A.
N.
B.
N
s
O c.
S
O D.
S
x for a smaller magnet at the position marked zin
A bus travels with a constant speed of 48km/h. How long will it take to travel 60km?
Answer:
It will take 1 hr and 15 mins.
Explanation:
Let's look at the speed equation:
s=d/t
We want to find the time, and we have the speed and the distance, so we rearrange the equation. t will be on one side and s and d will be on the other side.
t=d/s
t=60km/(48km/h)
t=1.25h
Which statement about momentum is false? a. Momentum is a force b. Momentum may be transferred c. Momentum is always conserved d. Momentum is a property only of moving objects
Answer:
So, option(a).
Explanation:
Momentum is the measure of motion of the object.
Momentum is given by the product of mass and the velocity of the object.
(a) It is false.
(b) It is true, momentum is transferred.
(c) It is true, As the momentum of the system is conserved when no external force is applied on the system.
(d) It is true, as the momentum is associated with the velocity of the object.
1) Explain the term fermentation
2) why is fermentation useful in making wine and beer
1. Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. The science of fermentation is known as zymology.
2. In general, the longer that fermentation goes on, the more sugar is converted into alcohol, resulting in a less sweet (or “drier”) and more alcoholic beverage. To produce beer, various grains are used instead of grapes as the source of sugars. ... This drying process converts the starches present in grain into sugars
Answer:
1.) Fermentation, chemical process by which molecules such as glucose are broken down anaerobically. More broadly, fermentation is the foaming that occurs during the manufacture of wine and beer, a process at least 10,000 years old.
2.) In general, the longer that fermentation goes on, the more sugar is converted into alcohol, resulting in a less sweet (or “drier”) and more alcoholic beverage. To produce beer, various grains are used instead of grapes as the source of sugars. ... This drying process converts the starches present in the grain into sugars.
Explanation:
HELPPPP I NEED THIS DONE PLSSS
Answer:
11. Food Chain
12. Food web
13. Habitat
Explanation:
The difference between food chain and food web is;
In a food chain, it shows one path of energy in one ecosystem.
In a food web, it shows various food chains in many ecosystems and how they are connected.
Nesse texto, um argumento usado para defender a ideia de que o filme A Caminho da Lua cumpre o papel de tocar e de entreter encontra-se no trecho:
“O filme foca em Fei Fei, garota de 12 anos que enfrenta dificuldades em superar o luto pela mãe e aceitar a nova noiva de seu pai.”. (1º parágrafo)
“... a menina decide construir um foguete para viajar até o satélite...”. (1º parágrafo)
“O que faz o longa se destacar é seu cenário mergulhado na cultura chinesa e a delicadeza com que o luto e sua superação são tratados.”. (2º parágrafo)
“... o foco quase exclusivo na garota prejudica todos os outros personagens...”. (3º parágrafo).
ajudem_me
Answer:O que faz o longa se destacar é seu cenário mergulhado na cultura chinesa e a delicadeza com que o luto e sua superação são tratados.
Explanation:
Por que se você pensar ela estava sempre buscando superar a morte da mãe.
A brick is lying on a table in a state of static equilibrium. If the mass of the brick is 7.52 kilograms, what is the normal force exerted by the table on the brick?
Answer:
-mg = -7.52*9.8 = - 73.696N
Answer:
See image
Explanation:
Plato
A cheetah runs at a speed of 27.6 m/s. If the
cheetah runs for 9.30 s, what is the distance the
cheetah runs? Show all your work.
Answer:
256.68m
Explanation:
that is the procedure above
A cheetah runs at a speed of 27.6 m/s. If the cheetah runs for 9.30 s, then the distance covered by the cheetah would be 256.68 metes
What is speed?The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is meter/second. The generally considered unit for speed is a meter per second.
The mathematical expression for speed is given by
speed = distance /Total time
As given in the problem A cheetah runs at a speed of 27.6 m/s. If the cheetah runs for 9.30 s, we have to calculate the distance covered by the cheetah
Distance=?
speed=27.6 m/s
time= 9.30 s
speed = distance /Total time
27.6 m/s = Distance /9.30 s
Distance = 27.6×9.30
=256.68 metes
Thus, the distance covered by the cheetah would be 256.68 metes
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The density of oil is 0.8 g/cm^3. What is the mass of 36 cm^3 of oil? + (1 Point) O 0.29 N O 28.09 28.8 g O 36.89
Answer:
density = mass/volume
density=0.8
volume=36
mass=?
0.8=mass/36
mass = 36x0.8=28.8g
A 4 mm object is observed by a magnifying lens as 1.25 cm. Calculate the ratio do/di.
Answer:
dₒ/dᵢ = 0.32
Explanation:
From the question given above, the following data were obtained:
Object height (Hₒ) = 4 mm
Image height (Hᵢ) = 1.25 cm
Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?
Next, we shall convert 4 mm to cm. This can be obtained as follow:
10 mm = 1 cm
Therefore,
4 mm = 4 mm × 1 cm / 10 mm
4 mm = 0.4 cm
Next, we shall determine the magnification of the lens. This can be obtained as follow:
Object height (Hₒ) = 4 mm
Image height (Hᵢ) = 1.25 cm
Magnification (M ) =?
M = Hᵢ/Hₒ
M = 1.25 / 0.4
M = 3.125
Finally, we shall determine the ratio of object distance (dₒ) to image distance (dᵢ). This can be obtained as follow:
Magnification (M) = 3.125
Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?
Magnification (M) = image distance (dᵢ) / object distance (dₒ)
M = dᵢ/dₒ
Invert
1/M = dₒ/dᵢ
1/3.125 = dₒ/dᵢ
dₒ/dᵢ = 0.32
Therefore, the ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] is 0.32
Accelaration is a derived quantity .Give reason
Answer:
The accerlation is a derived from the other quantities like change in velocity/time take etc.
"" damped force equation ""
Answer:
In many vibrating systems the frictional force Ff can be modeled as being proportional to the velocity v of the object: Ff = −cv, where c is called the viscous damping coefficient.
This is the last 2 questions i need! It’s due in 10 minutes please help!! I will mark brainliest asap
Answer:
I don't know 11 but in no. 10,
The ans is 3.66
Total distance = 10m+30m+15m = 55m
Total time = 5secs+7secs +3secs =15secs
Av speed = d/t =55/15 = 3.66 m/s
What is the force of gravity between Earth (6.0 × 1024 kilograms) and Venus (4.88 × 1024 kilograms)? The distance between the two planets is about 3.8 × 1010 meters. (The value of G is 6.673 × 10-11 newton meter2/kilogram2. The mass of Earth is 5.98 × 1024 kilograms.)
Answer:
ans: 13.53 × 10^17 Newton
Which instrument changes kinetic energy into electrical energy?
electric motor
hair drier
electric bell
dynamo
Answer:
Dynamo
Explanation:
As we all know, there are dynamos in bicycles. When we paddle the cycle, the wheels of the cycle rotates by generating kinetic energy. When the wheels rotate, the dynamo starts to rotate. This makes the motor inside the dynamo rotates and generate electrical energy.
The diagram show three different types of walls that could be built in a house. Through which hall would the heat lost be maximum.
Answer:
the thin steel wall because that wall is so very to fast broke
Find the emitted power per square meter and wavelength of peak intensity for a 3000 K object that emits thermal radiation.
Answer:
power per square meter = 4.593 × 10^(6) W/m²
Wavelength of peak intensity = 9.67 × 10^(-7) m
Explanation:
From Stefan-Boltzmann law, total emitted power per square meter is given as;
P/A = eσT⁴
where;
P is power
A is surface area
σ = Stefan-Boltzmann constant = 5.67 × 10^(-8) W/m².k⁴
T = temperature of the body = 3000 K
e = emissivity of the substance (for ideal radiation, it has a value = 1)
Thus, Plugging in the relevant values we have;
P/A = 1 × 5.67 × 10^(-8) × (3000)^(4)
P/A = 4.593 × 10^(6) W/m²
Let's find the wavelength of peak intensity.
From wiens displacement law, we know that;
λ_m × T = b
where;
λ_m = maximum wavelength
T = Temperature
b is Wien's displacement constant = 2.9 × 10^(−3) m/K
thus;
λ_m = b/T = (2.9 × 10^(−3))/3000 = 9.67 × 10^(-7) m
IV. The table below shows how the speed of a car changes with time. 1 What is the acceleration of the car? please help! :(
the ratio of the energy per second radiated by the filament of a lamp at 250k to that radiated at 2000k, assuming the filament is a blackbody radiator? The filament of a particular electric lamp can be considered as a 90%blackbody radiator. calculate the energy per second radiated when its temperature is 2000k if its surface area is 10∧-6 m²
Answer:
(a) [tex]\frac{P_{250k}}{P_{2000k}}=2.4\ x\ 10^{-4}[/tex]
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:
[tex]P = \sigma AT^4[/tex]
where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:
[tex]\frac{P_{250k}}{P_{2000k}}=\frac{\sigma A(250)^4}{\sigma A(2000)^4}\\\\\frac{P_{250k}}{P_{2000k}}=2.4\ x\ 10^{-4}[/tex]
(b)
Now, for 90% radiator blackbody at 2000 K:
[tex]P = (0.9)(5.67\ x\ 10^{-8}\ W/m^2.K^4)(1\ x\ 10^{-6}\ m^2)(2000\ K)^4[/tex]
P = 0.816 Watt
Explain the effect of the multiplier in the conversion of a moving coil galvanometer to a voltmeter.
Answer:
Explanation:
A galvanometer which is used for the measurement of a very small current can be converted to a voltmeter when it is connected to a high resistance or a multiplier is a series. The purpose of this is to reduce the amount of current that goes through the galvanometer so as prevent full scale deflection.
Un campo magn´etico uniforme B, con magnitud 1.2 mT, apunta verticalmente hacia arriba a lo largo del volumen del sal´on en que usted est´a sentado. Un prot´on de 5.3 MeV se mueve horizontalmente de sur a norte a trav´es de cierto punto en el salon. ¿Qu´e fuerza magn´etica deflectora act´ua sobre el prot´on cuando pasa por este punto? Cu´al es su aceleraci´on, la masa del prot´on es de 1.67x10−27 kg. Resp. 6.1x10−15 N; 3.7x1012 m/s2.
Answer:
F = 6.12 10⁻¹⁵ N, a = 3.66 10¹² m / s²
Explanation:
The magnetic force is
F = q v x B
bold letters indicate vectors, the modulus of this expression is
F = q v B sin θ
as they indicate that the magnetic field is vertical the proton moves horizontally the angle is 90º
suppose that the energy of the proton is totally kinetic
E = 5.3 MeV (10⁶ 1.6 10⁻¹⁹J / 1 eV) = 8.48 10⁻¹³ J
E = K = ½ m v²
v = [tex]\sqrt{2E/m}[/tex][tex]\sqrt{2 \ 8.48 \ 10^{-13} / 1.67 \ 10^{-27}}[/tex]
v = [tex]\sqrt{2 \ 8.48 \ 10^{-13} / 1.67 \ 10^{-27}}[/tex]
v = [tex]\sqrt{10.155 \ 10^{14}}[/tex]
v = 3.19 10⁷ m / s
we calculate
F = 1.6 10⁻¹⁹ 3.19 10⁷ 1.2 10⁻³
F = 6.12 10⁻¹⁵ N
The direction of this out is given by the right hand rule,
thumb in the direction of speed, south to north
fingers extended in the direction of the magnetic field, vertical
the probe points in the direction of the force for a positive charge, East
To calculate the acceleration we use Newton's second law
F = ma
a = F / m
a = 6.12 10⁻¹⁵ / 1.67 10⁻²⁷
a = 3.66 10¹² m / s²
the direction of the acceleration is the same as the direction of the force
A car traveling 77 km/h slows down at a constant 0.48 m/s2 just by "letting up on the gas." A) Calculate the distance the car coasts before it stops. B)Calculate the time it takes to stop. C)Calculate the distance it travels during the first second. D)Calculate the distance it travels during the fifth second.
Answer:
(a) 477 m
(b) 44.6 s
(c) 21.16 m
(d) 19.24 m
Explanation:
initial speed, u = 77km/h = 21.4 m/s
acceleration, a = - 0.48 m/s2
final speed v = 0
(a) let the stopping distance is s.
Use third equation of motion
[tex]v^2 = u^2 + 2 a s\\\\0 = 21.4^2 - 2 \times 0.48\times s\\\\s = 477 m[/tex]
(b) Let t is time.
Use first equation of motion
v = u + at
0 = 21.4 - 0.48 t
t = 44.6 s
(c) Let the distance is s in first second.
Use second equation of motion
[tex]s = u t + 0.5 at^2\\\\s = 21.4\times 1 - 0.5\times 0.48\times 1\\\\s = 21.4 - 0.24 = 21.16 m[/tex]
(d) distance traveled in 5 th second is given by
[tex]s = u + 0.5 a (2 n - 1) \\\\s = 21.4 - 0.5\times 0.48 \times (2\times 5 -1)\\\\s= 21.4 - 2.16 = 19.24 m[/tex]
