Answer:
a) A = 0.07129 m²
b) A / A ’= 1.77
Explanation:
In this exercise we are asked to find the area in SI units, so let's start by reducing the dimensions to SI units.
width a = 8.5 inch (2.54 cm 1 inch) (1 m / 100 cm)
a = 0.2159 m
length l = 13 inch (2.54 cm / 1 inch) (1 m / 100 cm)
l = 0.3302 m
The area of a rectangle is
A = l a
A = 0.3302 0.2159
A = 0.07129 m²
b) we have a second sheet with reduced dimensions
a ’= 3/4 a
l ’= ¾ l
Let's find the area of this glossy sheet
A ’= l’ a ’
A ’= ¾ l ¾ a
A ’= 9/16 l a
To find the factor we divide the two quantities
A / A ’= l a 16 / (9 l a
A / A ’= 1.77
a car accelerates from 10 m/s to 30 m/s as the traffic break up on the highway. the acceleration occurs over 3.5 seconds of time. determine the acceleration of the car.
Answer:
[tex] \boxed{\sf Acceleration \ (a) = 5.7 \ m/s^2} [/tex]
Given:
Initial velocity (u) = 10 m/s
Final velocity (v) = 30 m/s
Time taken (t) = 3.5 seconds
To Find:
Acceleration (a) of the car
Explanation:
From equation of motion:
[tex] \boxed{ \bold{ v = u + at}}[/tex]
Substituting value of v, u & t in the equation:
[tex] \sf \implies 30 = 10 + a(3.5) \\ \\ \sf \implies 30 - 10 = 3.5a \\ \\ \sf \implies 20 = 3.5a \\ \\ \sf \implies 3.5a = 20 \\ \\ \sf \implies a = \frac{20}{3.5} \\ \\ \sf \implies a = 5.7 \: m/s^2[/tex]
[tex] \therefore[/tex]
Acceleration (a) of the car = 5.7 m/s²
You and a friend each drive 58 km. You travel at 89. km/h, your friend at 94 km/h. How long will your friend wait for you at the end of the trip?
Answer:
2.1 minutes/ 126 seconds
Explanation:
Distance = speed x time
We can rearrange this equation for time:
Time = Distance/Speed
For you (89km/h):
Distance = 58km, Speed = 89km/h
Therefore time = 58/89 = 0.652 (3dp) hours
For friend:
Distance = 58km, Speed = 94km/h
Therefore time = 58/94 = 0.617 (3dp) hours
Difference in time = 0.652 - 0.617 = 0.035 hours.
Convert to minutes: 0.035 x 60 (because 60 min in hour) = 2.1
Your friend will be waiting for 2.1 minutes, or 126 seconds (2.1 x 60).
Hope this helped!
Marisol drives north at 64.3 km/h. How far does Marisol travel after 5.8 h?
Answer:
372.94 km
d= st
= (64.3 km/h)(5.8h)
=372.94 km
From the top of a cliff, a person throws a stone straight downward. The initial speed of the stone just after leaving the person's hand is 9.7 m/s. (a) What is the acceleration (magnitude and direction) of the stone while it moves downward, after leaving the person's hand? magnitude m/s^2direction Is the stone's speed increasing or decreasing? a. increasing b. decreasingAfter 0.51 s, how far beneath the top of the cliff is the stone? (Give just the distance fallen, that is, a magnitude.)________ m.
Answer:
a
[tex]a = 9.8 \ m/s[/tex]
Increasing
b
[tex]s = 6.22 \ m[/tex]
Explanation:
From the question we are told that
The initial speed is [tex]u = 9.7 \ m/s[/tex]
The time taken is [tex]t = 0.51 \ s[/tex]
Generally given that the stone is moving downward the acceleration is equivalent to the generally value of acceleration due to gravity and it would be increasing as the stone approaches the ground(toward the center of the earth )
Thus the acceleration is [tex]a = 9.8 \ m/s[/tex]
Generally from the equation of motion we have that
[tex]s = ut + \frac{1}{2} at^2[/tex]
=> [tex]s = 9.7 * 0.51 + \frac{1}{2} *9.8 * 0.51^2[/tex]
=> [tex]s = 6.22 \ m[/tex]
True or False: The study of the motion of objects is a foundational part of Physics
Answer:
True
Explanation:
In the foundational topics of physics mechanics consists of motion, energy and forces, theses areas are core concerns in the study of physics hence they are the foundational topics and are often times treated first in all matters.
What is motion?
Simply put, it is alternating from points to points.
the areas of study that involves motion and force together is call dynamics.
while the area of study of motion without any applied force is call statics.
Nina and Jon are practicing an ice skating routine. Nina is standing still. Jon, who is twice as heavy as Nina, skates toward her, pushing Nina away with force f. Assuming the system is closed, which statement is correct about this system? A. Nina experiences a force equal to f. B. Nina experiences a force equal to f/2.
If the system is closed, Nina will experience only a force equal to F exerted by Jon.
According to Newton's third law of motion, action and reaction is equal and opposite. That is the force applied to a stationary object is equal to the reaction exerted by the stationary object.
Applying this law, the force Jon applied on Nina is equal to the reaction Nina exerts on Jon.
If Jon exerts a force of F magnitude on Nina, consequently, Nina will experience the force of equal magnitude and exert equal reaction in opposite direction towards Jon.Also, if the system is closed, no additional force will be experienced by Nina, except the force applied by Jon.Thus, assuming the system is closed, Nina will experience only a force equal to F exerted by Jon.
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Bridget is riding her bicycle up a hill. Which statements are correct? Select five options.
Bridget is transferring energy to the bicycle.
The bicycle is using energy to do work.
Bridget has kinetic energy.
The bicycle has potential energy.
Bridget has nuclear energy.
The bicycle has mechanical energy.
Answer:
A,B,C,D, and F are correct
Explanation:
Answer:
Explanation:
A,B,C,D, and F
Suppose the same car had at one point an acceleration of 12m/s^2 and an initial velocity of 8m/s. After 2 seconds, what would be the car's final velocity
Answer: 32 m/s
Explanation: v = u + at
= 8 + 12*2
= 8 + 24
= 32 m/s
What should be done following health violations from inspection
Answer:
Correct identifies issues
Explanation:
If a proton is traveling north directly above the wire, what is the direction of the magnetic force on the proton due to the wire?
Answer:
Direction is downwards
Explanation:
This is by employing Flemings Right hand rule which says If you point your pointer finger in the direction the positive charge is moving, and then your middle finger in the direction of the magnetic field, your thumb points in the direction of the magnetic force pushing on the moving charge.
1. What is the longest-wavelength EM radiation that can eject a photoelectron from silver, given that the binding energy is 4.73 eV? Is this in the visible range?
2. Find the longest-wavelength photon that can eject an electron from potassium, given that the binding energy is 2.24 eV. Is this visible EM radiation?
Answer:
1. λ = 2.626 x 10⁻⁷ m = 262.6 nm
This wavelength is not in visible range. It lies in Ultra Violet Region.
2. λ = 5.546 x 10⁻⁷ m = 554.6 nm
This wavelength is in visible range.
Explanation:
The binding energy of in photoelectric effect is also known as work function. The formula for this is given as follows:
Binding Energy = Work Function = hc/λ
λ = hc/Work Function --------------- equation (1)
where,
h = Plank's Constant = 6.626 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = longest wavelength capable of ejecting electron = ?
(1)
Here,
Work Function = (4.73 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 7.568 x 10⁻¹⁹ J
Therefore,
λ = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(7.568 x 10⁻¹⁹ J)
λ = 2.626 x 10⁻⁷ m = 262.6 nm
This wavelength is not in visible range. It lies in Ultra Violet Region.
(2)
Here,
Work Function = (2.24 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 3.584 x 10⁻¹⁹ J
Therefore,
λ = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(3.584 x 10⁻¹⁹ J)
λ = 5.546 x 10⁻⁷ m = 554.6 nm
This wavelength is in visible range.
Waves with a wavelength of 10 meters will begin to touch bottom when the depth of water is _______ meters.
Answer:
When the depth is less than 0.5 m
Explanation:
Waves will begin to touch bottom when depth of the water is less than 1/20 of the wavelength. This type of wave is known as a shallow wave.
wavelength = 10 m
It will begin to touch bottom when its depth is less than
1/20 x 10 = 0.5 m
in your own words provide two advantages of using meters as a measurement of length rather than old measurements of length such as hands or steps
Answer:
it is accepted all over the world
it is more reliable than other kinds of measuring system
A typical cell has a membrane potential of -70 , meaning that the potential inside the cell is 70 less than the potential outside due to a layer of negative charge on the inner surface of the cell wall and a layer of positive charge on the outer surface. This effectively makes the cell wall a charged capacitor. Because a cell's diameter is much larger than the wall thickness, it is reasonable to ignore the curvature of the cell and think of it as a parallel-plate capacitor. How much energy is stored in the electric field of a 50--diameter cell with a 7.0--thick cell wall whose dielectric constant is 9.0?
Answer:
energy is stored is 2.2 × 10⁻¹³ J
Explanation:
The capacitance of the cell is given with the expression
C = (KE₀A) / d
k is the dielectric constant, A is the area of the cell, d is the thickness of the cell.
Now given that; the diameter is 50,
Area A = 4πR²
A = 4π × ( 25 × 10⁻⁶ m)²
A = 7850×10⁻¹² m²
our capacitance C = (KE₀A) / d
C = [9 ( 8.85 × 10⁻¹² C²/N.m² × 7850×10⁻¹² m² )] / 7×10⁻⁹ m
C = 8.93 × 10⁻¹¹ F
Now Energy stored
E = 1/2 × CV²
E = 1/2 × (8.93 × 10⁻¹¹ F) × ( 70 × 10⁻³ V)²
E = 2.2 × 10⁻¹³ J
Therefore energy is stored is 2.2 × 10⁻¹³ J
The energy that should be stored in the electric field should be 2.2 × 10⁻¹³ J.
Calculation of the energy:Since
The capacitance of the cell should be
C = (KE₀A) / d
Here,
k is the dielectric constant,
A is the area of the cell,
d is the thickness of the cell.
Now the diameter is 50,
So,
Area A = 4πR²
A = 4π × ( 25 × 10⁻⁶ m)²
A = 7850×10⁻¹² m²
Now
our capacitance C = (KE₀A) / d
C = [9 ( 8.85 × 10⁻¹² C²/N.m² × 7850×10⁻¹² m² )] / 7×10⁻⁹ m
C = 8.93 × 10⁻¹¹ F
Now Energy stored should be
E = 1/2 × CV²
E = 1/2 × (8.93 × 10⁻¹¹ F) × ( 70 × 10⁻³ V)²
E = 2.2 × 10⁻¹³ J
Therefore energy is stored is 2.2 × 10⁻¹³ J.
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A rock is dropped from a tall building. You can ignore air resistance. Determine its final speed and distance traveled after 4 seconds.
(A) speed = 20 m/s, distance = 80 m
(B) speed = 40 m/s, distance = 20 m
(C) speed = 40 m/s, distance = 80 m
(D) speed = 80 m/s, distance = 40 m
(E) speed = 20 m/s, distance = 40 m
Answer:
(C) speed = 40 m/s, distance = 80 m
Explanation:
According to Newton law of motion for a falling body:
v = u + gt
Where v is the final velocity, u is the initial velocity, t is the time taken to fall and g is the acceleration due to gravity.
Given that: t = 4 s, g = 10 m/s², u = 0 m/s(at top of building). Therefore substituting values:
v = 0 + 10(4)
v = 40 m/s
To find the distance h, we use the formula:
v² = u² + 2gh
Substituting values:
40² = 0² + 2(10)h
20h = 40² - 0²
20h = 1600
h = 1600 / 20
h = 80 m
The speed = 40 m/s, distance = 80 m
A motorcycle is following a car that is traveling at a constant speed on a straight highway. Initially, the car and the motorcycle are both traveling at the same speed of 19.0 m/s, and the distance between them is 52.0 m. After t1 = 5.00 s, the motorcycle starts to accelerate at a rate of 5.00 m/s2. How long does it take from the moment when the motorcycle starts to accelerate until it catches up with the car?
Answer:
t=2.14s
Explanation:
Since it asks us for the time it takes from the moment it starts accelerating, the first 5 seconds of movement mentioned is irrelevant here.
Next it'd be simple just to use the kinematic equation involving distance, time, and velocity:
∆d=V₀t+at²/2
From here we can move the change in distance over and use the quadratic formula to solve for time.
My work is in the attachment. Comment with any questions.
A hiker caught in a rainstorm absorbs 1.00 L of water in her clothing. If it is windy so that the water evaporates quickly at 20 ∘C, how much heat is required for this process?
Answer:
2260000 J
Explanation:
From the question,
Q = ml.................... Equation 1.
Where Q = Heat, m = mass of water, l = specific latent heat of vaporization.
But we can get the mass o water using the formula of density.
D = m/v........... Equation 2
Where D = density of water, v = volume of water.
make m the subject of the formula in equation 2
m = D×v............ Equation 3
Substitute equation 3 into equation 1
Q = D×v×l................. Equation 4
Given: v = 1.00 L = 0.001 m³.
Constant: l = 226000 J/kg, D = 1000 kg/m³
Substitute these values into equation 4
Q = 0.001(2260000)(1000)
Q = 2260000 J
Suppose you wanted to break a meter stick over your knee. The cross-section of a meter stick is rectangular. Will it be easier to break with the long side against your knee or with the short side against your knee? Cross-section of a meter stick : (i.e. looking down the end of a meter stick)
Answer:
It will be easier to break the meter rule with the long side against my knee.
Explanation:
To break the meter rule involves the principle of bending moment. The long side will require less force to generate the same amount of bending moment that will have to be generated to break the meter rule. The short side on the other hand will require more force to generate this mount of bending moment. This is because the shorter has a very small surface area, which concentrates the force on your knee. The pressure is then dissipated as more pressure to your knee. Th longer side has a lesser surface area so, most of the force is used in breaking the meter rule.
11. A circular racetrack has a radius of 500 m. What is the displacement of a bicyclist when she travels around the track from the north side to the south side
Answer:
≈159.15
Explanation:
So displacment is the fastest, or shortest way to get somewhere
Youd take your circumference (500) and find the diameter from that using the 2 formulas
C=2πr
d=2r
your answer would be ≈159.15
If im incorrect please correct me! Im only just relearning this stuff (im a freshman)
Solve the equation 30=10x for x.
Answer:
x = 3
Explanation:
30 = 10x
30/10 = x
3 = x
Answer:
X=3
Explanation: 30 = 10x for x
Divide both sides by 10
30/10 = 10x/10
3 = x
Does the distance between diffraction minima increase or decrease when the slit width is increased? Explain with reference to your data (observation) and theory
Answer:
the width of the slit is dividing therefore the distance to the minimums increases as the width of the slit decreases
Explanation:
In the diffraction phenomenon the intensity minima are described by
a sin θ = (m + ½) λ
without using trigonometry we can find an expression for the sine
tan θ = y / L
for small angles
Tan θ = sin θ/ cos θ = sin θ = y / L
a y / L = (m + ½) lam
y = (m + ½) λ L / a
we see that the width of the slit is dividing therefore the distance to the minimums increases as the width of the slit decreases
In the observation of the experiment the length of the pattern increases with the decrease in the width of the slit
A driver has a reaction time of 0.50 s , and the maximum deceleration of her car is 6.0 m/s² . She is driving at 20 m/s when suddenly she sees an obstacle in the road 50 m in front of her.
What is the distance she passes after noticing the obstacle before fully stopping?
Answer:
43.3 m
Explanation:
given :
the initial velocity of the car , u = 20m/s
The reaction time is 0.5s
the distance that the car will travel during the reaction time
= initial velocity x reaction time
= 20 m/s x 0.5 s
= 10 m
Now we turn our attention to the stopping distance AFTER she reacts and steps on the brakes:
recall that one of the forms that the equations of motions can be expressed is:
v² = u² + 2as
where v = final velocity = 0 because the car comes to a stop
u = initial velocity = 20m/s
a = acceleration = -6.0 m/s² (note negative sign because it is a deceleration)
s = distance traveled (we are asked to find this)
substituting the known values into the equation:
v² = u² + 2as
0² = 20² + 2(-6.0) s
0 = 400 - 12s
1.2s = 400
s = 400/12
s = 33.33 m
Total distance travelled
= distance during reacting time + distance while decelerating
= 10 + 33.3
= 43.3 m
Answer:
43.3 m
Explanation:
Given :
Reaction time = 0.5 sDeceleration = -6.0 m/s²Speed = 20 m/sObstacle Distance = 50 mDistance Travelled during Reaction Period
S = utS = 20 × 0.5S = 10 mUsing the formula v² - u² = 2aS :
Rearrange it so it is equal to 'S'S = v² - u² / 2aS = 0² - 20² / 2(-6) [v = 0, because speed is 0 when car stops]S = -400/-12S = 100/3 = 33.3 mDistance travelled after fully stopping :
10 m + 33.3 m43.3 mstate the basic law of charges
Answer:
Things that have the same charge push each other away (they repel each other). This is called the Law of Charges. … Things that have more electrons than protons are negatively charged, while things with fewer electrons than protons are positively charged. Things with the same charge repel each other.
Explanation:
A substance is soluble in water. It is added into the water and dissolves. More solute continues being added until it reaches a point where the newly added solute begins to sit on the bottom of the container without dissolving. What has happened? A. The solute has become a solvent. B. The solute was not actually soluble to begin with. C. The solute has become saturated. D. The solution has become saturated.
Answer:
option D
Explanation:
also to add.... there exists a solubility equilibrium between solid solute and the solution.
The newly added solute begins to sit on the bottom of the container without dissolving this represents that the solution has become saturated, Therefore the correct answer is D.
What is a Saturated Solution?It is a type of solution in which no more amount of solute can be dissolved any further, The saturated solution already contains the maximum amount of solute that can be dissolved within it.
The solution reached a point where the newly added solute starts to sit on the bottom this means the solution has become saturated.
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Identify two types of motion where an object's speed remains the same while it continues to change direction
Answer:
motion in which acceleration is orthogonal to travel directionmotion in which speed is constantExplanation:
1) Any motion in which the acceleration is orthogonal to the direction of travel will have this characteristic:
circular motion in a plane
motion of a charged particle in a magnetic field perpendicular to the direction of travel
__
2) Motion in which the speed is constant, regardless:
motion of a photon through a varying gravitational field
How many kg are equal to 325 g? Please explain
Answer:
.0325
Explanation:
you take 325 g times 0.001/ 1g and that equals to 0.325
Answer:
there is 0.325 kilograms in a gram
Explanation:
divide the mass by 1000
A sinewave has a period (duration of one cycle) of 35 μs. What is its corresponding frequency (no of completed cycles in a second), in kHz, expressed to 3 significant figures?
If the frequency of this sinewave is now reduced by a factor of 2.5, using the value calculated above to 3 significant figures, what will be the new period?
Express your answer in μs, to 3 significant figures
Answer:
We know that the relation between period and frequency is:
T = period.
f = frequency.
T = 1/f.
Then, if the period is 35 μs = 35x10^-9 seconds.
The frequency will be:
f = (1/ 35x10^-9 s) = (1/35s)*10^9
now, 1Hz = 1/s
1KHz = 1/1000s = 10^-3 s
f = (10^9/35)*10^-3 KHz = 10^6/35 KHz = 28,571.429 KHz.
Now we must divide this by 2.5:
28,571.429 KHz/2.5 = 11,428.572 KHz
Now we can use the relation:
T = 1/f
T = 1/11,428.572 KHz = (1/11,428.572 Hz)*10^-3
T = 8.750x10^-8 seconds.
And we want this expressed in μs = 10`-9 seconds, we have:
T = 8.750x10^-8 s = (10/10)8.750x10^-8 s = 87.50x10`-9s = 87.50 μs
So as expected, if the frequency is reduced by a factor of 2.5, the period will increase by a factor of 2.5
As the initial period was 35 μs, and:
2.5*35 μs = 87.5 μs
Whenever you push an object across a frictional surface, it starts out taking a lot of force to push to get the object moving. However, once the object starts moving, it is much easier to keep it moving. What does this tell you about one of the main differences between static and kinetic friction?
a.Static friction only depends on the surface material, while kinetic friction only depends on the motion
b Kinetic and Static friction are the exact same thing
c Static friction and kinetic friction are combined in one at all times, but static friction is just not seen during the motion
d Static Friction is much stronger than kinetic friction, so it takes more force to get an object moving than it does to keep it moving
Answer:
The answer is A
Explanation:
Here's an example. A child is in school taking a test. They have made a mistake on a question, and want to erase it. The eraser is made out of a type of rubber, the rubber has friction, which means the eraser has something that's going to resist movement. Now the child has exerted enough force to get it moving, and it's moving, it won't stop unless the child stops exerting force to keep it moving. Both Newton's 1st and 3rd law explain the action of moving something on a surface with friction.
What is the maximum speed with which a 1200-kg car can round a turn of radius 90.0 m on a flat road if the coefficient of static friction between tires and road is 0.70?
2. Is this result independent of the mass of the car?
Answer:
78.6m/s
Explanation:
We know that frictional force also contributes to the centripetal force that keeps the car in circular motion in the turn
And is given as
F= mv²/r
But the frictional force is
F= ugm
= = 0.7*1200*9.8= 8232N
To find maximum velocity v we say
V= √F x r/m
= √ 8232* 90 /1200
= 78.6m/s
2. Yes it is independent of mass of car
Answer:
The value is [tex]v = 24.85 \ m/s[/tex]
Yes
Explanation:
From the question we are told that
The mass of the car is [tex]m= 1200 \ kg[/tex]
The radius is [tex]r = 90 \ m[/tex]
The coefficient of static friction is [tex]\mu_s = 0.70[/tex]
Generally at maximum speed the centripetal force acting on the car is equal to the friction force on the car
So
[tex]F_c = F_f[/tex]
[tex]\frac{m v^2}{r} = \mu_s * m * g[/tex]
=> [tex]v = \sqrt{\mu_s * g * r }[/tex]
=> [tex]v = \sqrt{ 0.70 * 9.8 * 90 }[/tex]
=> [tex]v = 24.85 \ m/s[/tex]
Yes the value is independent of the mass because from the equation above we see that v is independent of mass
How could you test the hypothesis that elephants interpreted the ground signal as being farther away than the air signal?
Answer:
One way to test the hypothesis is to create two waves, one in the air and one on the ground at the same time. One of them for the elephant to get closer and another for the elephants to move away. Observe the reaction of the animal and with this we know which sound came first.
Explanation:
This hypothesis is based on the fact that the speed of sound in air is v = 343 m / s with a small variation with temperature.
The speed of sound in solid soil is an average of the speed of its constituent media, giving values between
wood 3900 m / s
concrete 4000 m / s
fabrics 1540 m / s
earth 5000 m / s wave S
ground 7000 m / s P wave
we can see that the speed on solid earth is an order of magnitude greater than in air.
One way to test the hypothesis is to create two waves, one in the air and one on the ground at the same time. One of them for the elephant to get closer and another for the elephants to move away. Observe the reaction of the animal and with this we know which sound came first.
From the initial information, the wave going through the ground should arrive first.
To test the hypothesis that elephants interpreted the ground signal as being farther away the air signal is to see how fast they react by high and low frequency sounds. This however can be done by creating two waves, one in the air and one on the ground at the same time. One of them for the elephant to get closer and another for the elephants to move away. The reaction of the animal is then observed and via the first sound from one of them
HypothesisA hypothesis is an assumption, an idea that is proposed for the sake of argument so that it can be tested to see if it might be true.
In non-scientific use, hypothesis and theory are often used interchangeably.
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