Answer:
theory
Explanation:
A scientist can contribute to the formation of a theory in a particular subject by conducting research along the line of that subject.
Conducting research requires the formation of a hypothesis and testing the hypothesis by conducting a relevant experiment during which data are gathered, analyzed, and interpreted in order to falsify or accept the hypothesis.
A good experiment must be replicate-able. When the same experiment is repeated by different independent researchers and the same conclusion is arrived at, this could potentially lead to the formation of a theory.
Hence, a scientist can contribute to the formation of a theory by conducting an experiment with replicability in order to test a hypothesis.
A body is thrown vertically upwards, remaining 4s in the air. Calculate the maximum height that the body reaches.
Answer:
20 m
Explanation:
Given:
v = 0 m/s
a = -10 m/s²
t = 4 s / 2 = 2 s
Find: Δy
Δy = vt − ½ at²
Δy = (0 m/s) (2 s) − ½ (-10 m/s²) (2 s)²
Δy = 20 m
The magnetic field in a cyclotron is 1.25 T, and the maximum orbital radius of the circulating protons is 0.40 m. (a) What is the kinetic energy of the protons when they are ejected from the cyclotron
Answer:
1.92 x 10⁻¹²J
Explanation:
The magnetic force from the magnetic field gives the circulating protons gives the particle the necessary centripetal acceleration to keep it orbiting round the circular path. And from Newton's second law of motion, the force(F) is equal to the product of the mass(m) of the proton and the centripetal acceleration(a). i.e
F = ma
Where;
a = [tex]\frac{v^2}{r}[/tex] [v = linear velocity, r = radius of circular path]
=> F = m[tex]\frac{v^2}{r}[/tex] ------------(i)
We also know that the magnitude of this magnetic force experienced by the moving charge (proton) in a magnetic field is given by;
F = q v B sin θ ----------(ii)
Where;
q = charge of the particle
v = velocity of the particle
B = magnetic field
θ = the angle between the velocity and the magnetic field.
Combining equations (i) and (ii) gives
m[tex]\frac{v^2}{r}[/tex] = q v B sin θ [θ = 90° since the proton is orbiting at the maximum orbital radius]
=> m[tex]\frac{v^2}{r}[/tex] = q v B sin 90°
=> m[tex]\frac{v^2}{r}[/tex] = q v B
Divide both side by v;
=> m[tex]\frac{v}{r}[/tex] = qB
Make v subject of the formula
v = [tex]\frac{qBr}{m}[/tex]
From the question;
B = 1.25T
m = mass of proton = 1.67 x 10⁻²⁷kg
r = 0.40m
q = charge of a proton = 1.6 x 10⁻¹⁹C
Substitute these values into equation(iii) as follows;
v = [tex]\frac{(1.6*10^{-19})(1.25)(0.4)}{(1.67*10^{-27})}[/tex]
v = 4.79 x 10⁷m/s
Now, the kinetic energy, K, is given by;
K = [tex]\frac{1}{2}[/tex]mv²
m = mass of proton
v = velocity of the proton as calculated above
K = [tex]\frac{1}{2}(1.67*10^{-27} * (4.79 * 10^7)^2 )[/tex]
K = 1.92 x 10⁻¹²J
The kinetic energy is 1.92 x 10⁻¹²J
Part E Now convert the time from seconds to years. This value is the approximate age of the universe. Write the age in scientific notation. Use the conversion, 1 year = 3.154 × 107 seconds.
Explanation:
The age of the universe is 13.8 billion years.
We know that,
1 billion years = 10⁹ years
So,
[tex]13.8\ \text{billion years}=13.8\times 10^9\ \text{years}[/tex]
We need to convert the age of the universe to the scientific notation.
Since, [tex]1\ \text{year}=3.154\times 10^7\ s[/tex]
So,
[tex]13.8\times 10^9\ \text{years}=13.8\times 10^9\times 3.154 \times 10^7\\\\=4.35\times 10^{17}\ s[/tex]
So, the age of the universe is [tex]4.35\times 10^{17}\ s[/tex].
Answer:
So the universe is approximately 1.34 x 10^10 years old
Explanation:
Edmentum
A scientist is studying the effects of sunlight on rose bushes. Which of the
following is a testable question about this topic?
Answer:
Does more sunlight make rose bushes grow taller?
Explanation:
When conducting a research, the researcher usually poses research questions in order to confirm or disprove the research hypothesis. A research question addresses the key issues and questions that the research project is intended to answer. Good research questions always aim at improving the body of knowledge on the selected topic of the research. Research questions must be narrowed down to specific details of the topic. They must also be testable, they must not be vague.
If I am studying the effect of sunlight on rose bushes, then the question, 'does more sunlight make rose bushes grow taller?' Is apt to the research because it can be tested by exposing various thorn bush plants to varying degrees of sunlight and recording my observation.
Answer:
If rose bushes receive more hours of sunlight each day, they will grow taller.
Explanation:
I just answered it on Apex, and they like to switch up how they word things sometimes.
Find the speed of the mobile after 4 seconds
Answer:
27 m/s
Explanation:
V_final = v_initial + a*t
V_final = 15 + 3 * 4
V_final = 27 m/s
Select the correct answer.
According to the Universal Law of Gravitation, every object attracts every other object in the universe. Why can’t you feel the force of attraction between you and Mars?
A.
There is no force of attraction between you and Mars.
B.
Your mass is too low.
C.
Mars is a larger planet than Earth.
D.
Mars is a long distance away.
Answer:
D. Mars is a long distance away
when vector contains distance and direction it also known as
When vector contain distance and direction it is also known as displacement .
A duck is 12 m from the edge of a pond. A student stands in the middle of the pond
and creates ripples that travel past the duck and towards the edge of the pond. The
ripples are produced uniformly at 2 ripples per second. The student determines that
the ripples take 3.0 seconds after they pass the duck to reach the edge of the pond.
Determine the wavelength of the ripples.
Answer:
The wavelength is 2 meters
Explanation:
The relationship between the frequency, the speed and the wavelength is given by the relation;
v = f × λ
The given parameters are;
The distance of the duck from the edge of the pond = 12 m
The number of ripples produced per second = Frequency, f = 2 Hz
The time it takes the ripple to reach the edge of the pond after travelling past the duck = 3 seconds
Therefore, speed of the wave, v = Distance/time = 12 m/(3 s) = 4 m/s
The wavelength, λ, is therefore;
λ = v/f = (4 m/s)/(2 Hz) = 2 meters.
we can catch a rolling ball but not a flying bullet?? give reason
Answer:
yeah this statement is tru
Explanation:
it is because the speed of the bullet is more than the speed of rolling ball .so from this reason we cannot catch a bullet.
A bullet will be moving much faster than a rolling ball. Even seeing a bullet in flight requires it to be extremely low velocity.
If three cars, each of mass 1000 kg , occupy the NE, SE, and SW corners, determine the coordinates of the CM of the loaded ferryboat relative to the center of the raft. Take the origin to be at the CM of the raft.
Answer:
Using X = sum( x's * mass)/sum( masses)
= [(0)*(6400)+ (-9.5*1000) + (9.5)*(1000) + (9.5)*(1000)]/(6400+1000+1000+1000)
= 1.01 m
Y = sum( y's * mass)/sum( masses)
= [(0)*(6400) + (9.5)*(1000) +(-9.5)*(1000) + (-9.5)*(1000)]/ (6400+1000+1000+1000)
= -1.01 m
Q. A train accelerates from 36 km/h to 54 km/h in 10 sec. (i) Acceleration (ii) The distance travelled by car.
u=10m/s
v=15m/s
acceleration=
v_u/ t
5/10
0.5
Radar uses radio waves of a wavelength of 2.5 m . The time interval for one radiation pulse is 100 times larger than the time of one oscillation; the time between pulses is 10 times larger than the time of one pulse. What is the shortest distance to an object that this radar can detect
Answer:
The minimum distance to the object that the radar can detect is 124.995 m
Explanation:
Here, we are to calculate the shortest distance to an object the radar in the question can detect.
Mathematically;
v = c/λ
Where v is the frequency, c is the speed of light and λ is the wave length
Thus;
v = (3 * 10^8)/2.5 = 1.2 * 10^8 Hz
Mathematically, the time period
t = 1/v = 1/(1.2 * 10^8) = 0.000000008333 = 8.333 * 10^-9 sec
From the question, we are told that the transmitting time is 100 times a single oscillation
Transmitting time = 100 * one oscillation
Hence Transmitting time = 100 * 8.33 * 10^-9 = 8.33 * 10-7
Mathematically;
Minimum distance =( Transmitting time * speed of light)/2 =
(8.33 * 10^-7 * 3 * 10^8)/2 = 124.995 m
Formulating a Hypothesis: Part II
Now you will focus on a second hypothesis. This
hypothesis can be very similar to the first, but this time
you want to focus only on the second variable in
question, speed. What could be a hypothesis that would
illustrate the relationship between speed and kinetic
energy? Use the format of "if.. then... because..." when
writing your hypothesis.
If we have a ball rolling its speed could determine the amount of
kinetic energy in it while in movement
Explanation:
The kinetic energy of an object is given by :
[tex]E=\dfrac{1}{2}mv^2[/tex]
m is mass of the object
v is the speed of the object
It is clear from the above relation that the kinetic energy of the object is directly proportional to the product of mass and velocity.
The hypothesis can be :
If the speed of the object increased then its kinetic energy increase because kinetic energy is directly proportional to ist speed.
The kinetic energy of an object is given by :
m is mass of the object
v is the speed of the object
It is clear from the above relation that the kinetic energy of the object is directly proportional to the product of mass and velocity.
The hypothesis can be :
If the speed of the object increased then its kinetic energy increase because kinetic energy is directly proportional to its speed.
Indicate the direction of heat flow in each scenario. Scenario A: Scenario B: Scenario C: Scenario D:
Answer:
Scenario A: toward object 1
Scenario B: toward object 2
Scenario C: toward object 1
Scenario D: toward object 1
Explanation:
The heat transfer will take place for different cases are as follow
A: From skin to lotion
B: From lasagna to plate
C: Lava to ocean water
D: From sidewalk to egg
What is heat transfer?Heat always flows from a higher temperature body to a low-temperature body. Heat transfer, any or all of several kinds of phenomena, is considered a mechanism, that conveys energy and entropy from one location to another.
The specific mechanisms are usually referred to as convection, thermal radiation, and conduction (see thermal conduction).
Conduction involves the transfer of energy and entropy between adjacent molecules, usually a slow process.
Convection involves the movement of heated fluid, such as air, usually a fairly rapid process.
Radiation refers to the transmission of energy as electromagnetic radiation from its emission at a heated surface to its absorption on another surface, a process requiring no medium to convey the energy
The heat transfer will take place for different cases are as follow
A: From skin to lotion
B: From lasagna to plate
C: Lava to ocean water
D: From sidewalk to egg
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On January 22, 1943, in Spearfish, South Dakota, the temperature rose from −4.00°F to 45.0°F over the course of two minutes (the current world record for the fastest recorded temperature change). By how much did the temperature change on the Celsius scale?
Answer:
The change on the Celsius scale is 27.22 °C.
Explanation:
The conversion of Fahrenheit to Celsius is the following:
[tex]T = \frac{5}{9}(^{\circ} F - 32)[/tex]
So, we need to convert T₁ and T₂ from °F to °C:
[tex]T_{1} = \frac{5}{9}(^{\circ} F - 32) = \frac{5}{9}(- 4 - 32) = -20 ^{\circ} C[/tex]
[tex]T_{2} = \frac{5}{9}(^{\circ} F - 32) = \frac{5}{9}(45 - 32) = 7.22 ^{\circ} C[/tex]
Hence, the change on the Celsius scale is:
[tex] \Delta T = T_{2} - T_{1} = 7.22 - (-20) = 27.22 ^{\circ} C [/tex]
Therefore, the change on the Celsius scale is 27.22 °C.
I hope it helps you!
For the electric circuit given below, calculate: 3 (i) the equivalent resistance of the circuit, (ii) the total current drawn from the battery and (iii) the voltage across 7Ω resistor.
Answer:
1)31/3Ω
2)18/31A
3)4.06V
Explanation:
According to the diagram and 10 Ω resistors are parallel to each other, parallel resistor can be calculated using the formula below
1/R= 1/R1 + 1/R2
But we know R1= 5 Ω and R2= 10 Ω
1/R= 1/5 + 1/10
R= 10/3 Ω
=3.33 Ω
Then if we follow the given figure, 10/3 Ω and 7Ω are now in series then
Req = 10/3 +7
Req= 31/3 Ω
Therefore, equivalent resistance = 31/3 Ω
According to ohms law we know that V= IR
Then I= V/R
Where I= current
R= resistance
V= voltage
I= 6/(31/3)
I= 18/31A
We can now calculate the voltage accross the resistor which is
V=(18/31)× 7
V=4.06V
Therefore, the voltage accross the 7 ohm resistor is 4.06V
CHECK THE FIQURE AT THE ATTACHMENT
The plates of a parallel-plate capacitor are maintained with a constant voltage by a battery as they are pushed together, without touching. How is the amount of charge on the plates affected during this process
Answer:
The amount of charge increases.
Explanation:
For a capacitor that has its plates still connected to a battery, the voltage on the capacitor remains constant. If the distance between the two plates of this capacitor is decreased, the capacitance will increase, and then the charge on the plate will increase in accordance with the relationship
Q =CV
From this relationship, if V is held constant, then Q has to increase for C to increase also.
How do you find time with current and charge
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Current Electricity .
Since we know that, Current is Charge per unit time.
so we get as,
Q = I*t
here, Q = charge, I = current, t = time.
a solid weighs 20gf in air and 18 gf in water.Find the specific gravity of the solid. Please show your work.
Answer: It is given that A body weighs 20gf in air and 18. 0gf in water. Hence, the answer X-3 = 7.
You are given three pieces of wire that have different shapes (dimensions). You connect each piece of wire separately to a battery. The first piece has a length L and cross-sectional area A. The second is twice as long as the first, but has the same thickness. The third is the same length as the first, but has twice the cross-sectional area. Rank the wires in order of which carries the most current (has the lowest resistance) when connected to batteries with the same voltage difference.
A. Most Current
B. Wire of length L and area 2A
C. Wire of length L and area A
D. Wire of length 2L and area A
E. Least Curren
Answer:
Explanation:
Resistance of first wire
R₁ = ρL / A where ρ is specific resistance
for second wire the resistance
R₂ = ρ2L / A = 2 ρL / A
For third wire
R₃ = ρL /2 A
The resistance is in the order
R₂ > R₁ > R₃
So , current will be maximum in R₃
I₃ > I₁ > I₂
Where I₁ , I₂ and I₃ is current in first , second and third wire .
analyze this physics mystery and be marked brainliest
Answer:
The two middle chains are for suspension of the glass surface, while the fours chains at all corners prevents tilting
Explanation:
From the picture, the the frame bearing the glass surface is suspended by the two metal chains at the middle,
While the balance to avoid tilting to either directions is maintained by the four chains at all corners.
Law of conservation
of momentum
Answer:
Explanation:
Law of conservation of momentum is applied in solving collision problem. When two body collides, their momentum after collision can be determined using the law.
The law States that the sum of momentum of two bodies before collision is equal to the sum of their momentum after collision. Before collision, both bodies moves with a different velocity while during some cases, the bodies moves with a common velocity after collision.
Whether they move with or without the same velocity depends on the type of collision that exists between them after the collision. After collision, some object sticks together and move with a common velocity while some doesn't.
If the bodies sticks together after collision, the type of collision that occur is inelastic (energy is not conserved) and if they splits after collision, the type of collision that occur is an elastic collision (energy is conserved).
Let m1 and m2 be the masses of the bodies
u1 and u2 be their velocities before collision
v1 and v2 be their velocities after collision.
According to the law;
m1u1 + m2u2 = m1v1 + m2v2
Note that momentum = mass × velocity of the body.
3.) [15 points] A physics teacher is on the west side of a small lake and wants to swim across and up at a point directly across from his starting point. He notices that there is a current in the lake and
that a leaf floating by him travels 4.2m [S] In 5.0s. He is able to swim 1.9 m/s in calm water,
(a) What direction will he have to swim in order to arrive at a point directly across from his position?
Answer:
The teacher should swim in a direction 29.24° North of East
Explanation:
Given that the there is a water current across the lake, and the physics teacher intends to swim directly across the lake, the direction the physics teacher will have to swim is found as follows;
The speed of the water current is given by the speed of the floating leaf traveling with the water current
Distance traveled by the leaf = 4.2 m South
Time of travel of the leaf = 5.0 s
Speed of leaf = 4.2/5 = 0.84 m/s = Speed of the water current
Swimming peed of the teacher, v = 1.9 m/s
To swim directly across the lake, the teacher has to swim slightly in the opposite direction of the water current, the y-component of the teacher's swimming speed should be equal to and opposite that of the speed of the water current.
Y-component of v = v×sin(θ), where θ is the angle of the direction, the teacher should swim
Therefore;
1.9 × sin(θ) = 0.84
sin(θ) = 0.84/1.9 = 0.44
θ = 26.24°
That is the teacher should swim in a direction 29.24° North of East.
To cross the lake the teacher has to swim in a direction 29.24° North of the East
Finding the direction of speed required:
The speed of the water current can be derived from the speed of the floating leaf :
The distance traveled by the leaf L = 4.2 m South
Time taken T = 5s
So, the speed of the leaf is:
u = 4.2/5
u = 0.84 m/s South
So, the speed of the current is 0.84 m/s South
Now, it is given that the speed of the teacher is, v = 1.9 m/s East
To cross the lake the speed of the teacher must be in a Northeast direction so that the North component of the speed of the teacher cancels out the speed of the current which is directed towards the South.
Let, the speed of the teacher makes an angle of θ from the EAST.
So, the North component is given by:
v(north) = vsinθ
it must be equal to the speed of the current:
vsinθ = u
1.9 × sinθ = 0.84
sinθ = 0.84/1.9
sinθ = 0.44
θ = 26.24°
The teacher should swim in a direction 29.24° North of East.
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identify the motion when a car is moving with constant speed along a curve
Answer:
Uniform circular motion
Explanation:
When a car is moving with constant speed along a curve, it will said to have uniform circular motion. The speed of the car remains constant in this case. But its velocity keeps on changing. The velocity can be calculated by drawing the tangent on the circle. Hence, the motion of the car is uniform circular motion.
Answer:
Uniform motion
Explanation:
The motion when a car is moving with constant speed along a curve is an example of uniform motion.
A car moving at constant speed covers equal distances in equal intervals of time. The average speed remains the same in uniform motion.
The curve defines the path of the motion and the speed remains constant.
Calculate the speed of a car that travels 355km in 15 hours , a good answer please
Answer:
23.67 km / hr
Explanation:
car travels 355 km (d)
duration = 15 hrs (t)
average speed formula = v = d / t
v = 355 km / 15 hr
v = 23.67 km / hr
Explanation:
Hello, there!!!
Here, your question is asking about the speed and the given are:
distance (s)= 355km
time (t) = 15hrs.
speed (v)=?
now,
we have the formula:
v= s/t
or, v = 335km /15 hrs.
Therefore, the speed of car was 23.67km/hr.
Hope it helps..
Unpolarized light, with an intensity of I0, is incident on an ideal polarizer. A second ideal polarizer is immediately behind the first and its axis of polarization is oriented at an angle of 60° relative to the first polarizer’s. How much of the light will be transmitted through the system?
Answer:
The light transmitted through the system will be 0.125*I₀.
Explanation:
The light transmitted through the system can be found using Malus Law:
[tex] I = I_{0}cos^{2}(\theta) [/tex] (1)
Where:
I: is the intensity of the light transmitted
I₀: is the initial intensity
θ is the angle relative to the first polarizer’s = 60°
Because the light transmitted by the first polarizer is dropped by half, the equation (1) results as:
[tex] I = \frac{I_{0}}{2}cos^{2}(\theta) [/tex]
[tex] I = \frac{I_{0}}{2}cos^{2}(60) [/tex]
[tex] I = 0.125I_{0} = \frac{1}{8}I_{0} [/tex]
Therefore, the light transmitted through the system will be 0.125*I₀.
I hope it helps you!
When we double the distance between a source of light and the
surface on which it falls, the amount of illumination on the surface
decreases to
(what fraction) of the
original illumination.
The amount of lighting on a surface drops to (1/4) of the initial illumination when the distance between a light source and the surface it falls on is doubled.
What is illumination?The amount of light or luminous flux that falls on a surface is known as illumination. It is expressed as lux or lumens per square meter.
The square of the distance has an inverse relationship with the light intensity;
[tex]\rm I = \frac{1}{r^2}[/tex]
Where,
I is the light intensity
r is the distance
Let r is the distance and I is the sound intensity for case 2;
r' = 2r
[tex]\rm I' = \frac{1}{(2r)^2} \\\\ I' = \frac{1}{4r^2} \\\\ I' = \frac{I}{4}[/tex]
When we double the distance between a source of light and the surface on which it falls, the amount of illumination on the surface decreases to(1/2) of the original illumination.
Hence the value of the fraction is 1/4.
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A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 newtons. What is the acceleration of the wagon?
Explanation:
F = ma
2 N = (10 kg) a
a = 0.2 m/s²
A car travels from city A to city B separated by 282 km and the journey takes approximately 6 hours and 32 minutes. If they come back in 8 hours. What is your average speed throughout the journey? What is its average speed?
Answer:
38.8 km/hr
Explanation:
The total distance is 2 × 282 km = 564 km.
The total time is 6 hr 32 min + 8 hr = 14 hr 32 min = 14.533 hr.
The average speed is:
(564 km) / (14.533 hr)
38.8 km/hr
It a process or act of natural growth.