Answer:
-5%
Explanation:
We know that volume is mass/density
So to find percentage
Let first mass be = M1
Second be 0.94m( 1-6%)
Second density be=0.99
First density be d
So finlq volume v2= 0.94m/0.99p=
V2= (0.94/0.99)V1
V2= 0.95v1
So volume decrease will be 1-0.95= 0.05
= -5%
A car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.76 m/s2 for t1 = 20 s. At that point the driver notices a tree limb that has fallen on the road and brakes hard for t2 = 5 s with a constant acceleration of a2 = -5.93 m/s2.Write an expression for the car's speed just before the driver begins braking, v1.If the limb is on the road at a distance of 550 meters from where the car began its initial acceleration, will the car hit the limb?
Answer:
1) an expression for the car's speed is given as
v = u + at
where
v is the car's speed
u is the initial speed of the car
a is the car's acceleration
t is the time spent accelerating
2) The car does not hit the tree limb
Explanation:
The initial velocity of the car = 0 m/s (since it accelerates from rest)
acceleration of the car = 1.76 m/s
time spent accelerating = 20 s
For the car's speed just before the driver begins braking, we use the expression
v = u + at
where v is the final speed of the car just before the driver begins braking
u is the initial velocity with which the car starts moving
a is the acceleration of the car
t is the time spent accelerating from u to v
substituting values, we have
v = 0 + 1.76(20)
v = 0 + 35.2
the car's speed v = 35.2 m/s
In this time the car accelerates, the car moves a distance given by
s = ut + [tex]\frac{1}{2}[/tex]a[tex]t^2[/tex]
where s is the distance covered in this time
u is the initial speed of the vehicle
a is the acceleration
t is the time taken
substituting, we have
s = 0(20) + [tex]\frac{1}{2}[/tex](1.76)[tex]20^{2}[/tex]
s = 0 + 352
distance s = 352 m
When the driver brakes, we have
time spent braking = 5 s
acceleration = -5.93 m/s
and the distance to the limb = 550 m from where the car begun
to get the distance covered in this period, we use the expression
s = ut + [tex]\frac{1}{2}[/tex]a[tex]t^2[/tex]
where s is the distance traveled at this time
u is the speed of the car before it starts braking = 35.2 m/s
a is the acceleration at this point
t is the time taken to decelerate to a stop
substituting values, we have
s = 35.2(5) + [tex]\frac{1}{2}[/tex](-5.93 x [tex]5^2[/tex])
s = 176 - 74.125
s = 101.88 m
Total distance moved by the car = 352 m + 101.88 m = 453.88 m
Since the total distance traveled by the car is less than the distance from the starting point to the place where the tree limb is, the car does not hit the tree limb.
20 POINTS 20 POINTS On a bright sunny day you decide to take a walk. You begin at your home and walk 1000 meters to an ice cream shop in 10 minutes. You spend 15 minutes ordering your ice cream and then return home. Since you have an ice cream cone in your hand, it takes 20 minutes to walk home. 1. Find the total displacement and total distance traveled. 2. Find your average speed and average velocity in meters/min. 3. Find your average speed and average velocity in meters/sec.
Answer:
A) Total Distance = 2000 m and Total displacement = 0 m
B) Average Speed = 44.44 m/min and Average Velocity = 0 m/min
C) Average Speed = 0.7407 m/s and Average velocity = 0 m/s
Explanation:
A) Distance to reach ice cream shop from home = 1000 meters
Therefore distance to get back home would also be 1000 meters.
Total distance traveled = 1000 + 1000 = 2000 metres
Since journey started at home and ended at home, then total displacement = 0 metres.
B) Average speed = Total distance/total time.
Total time = 10 + 15 + 20 = 45 minutes
Since total distance = 2000 m
Then;
Average speed = 2000/45
Average speed = 44.44 m/min
Average velocity = Total displacement/total time
Average velocity = 0/45 = 0 m/min
C) We now want answers in B to be in m/s.
Total time = 45 minutes.
From conversion, 60 seconds make 1 minute. Thus, 45 minutes = 45 × 60 = 2700 seconds
Thus;
Average Speed = 2000/2700
Average Speed = 0.7407 m/s
Average displacement = 0/2700 = 0 m/s
A typical atom has a diameter of about 1.0×10−10m.
Approximately how many atoms are there along a 2.0 −cm line?
Express your answer using two significant figures.
Answer:
10m
Explanation:
if it was at the 2.0 line it would be 10 m
If a typical atom has a diameter of about 1.0×10⁻¹⁰ m, then there are approximately atoms are there along a 2.0-centimeter line.
What are significant figures?In positional notation, significant figures refer to the digits in a number that is trustworthy and required to denote the amount of something, also known as the significant digits, precision, or resolution.
As given in the problem If a typical atom has a diameter of about 1.0×10⁻¹⁰ m, then we have to find out approximately how many atoms are there along a 2.0-centimeter line,
diameter of the one atom = 1.0×10⁻¹⁰
approximate number of atoms in 2 cm line = 2 ×10⁻² /( 1.0×10⁻¹⁰ )
=2 ×10⁸ atoms
Thus, there are approximately 2 ×10⁸ atoms are there along a 2.0-centimeter line.
Learn more about significant figures here,
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a car moves 8 m in 4 s at a comstant velocity. what is the cars acceleration
Answer:
Zero.
Explanation:
Acceleration is defined as change in velocity per unit time. For constant, the acceleration is zero.
[tex]\hat{a} =\frac{ \delta V}{t}[/tex]as [tex]\delta[/tex][tex]v\\[/tex] is zero.
The main force(s) acting on the puck after receiving the kick is (are):_________.A) a downward force of gravity and an upward force exerted by the surfaceB) a downward force of gravity, and a horizontal force in the direction of motionC) a downward force of gravity, an upward force exerted by the surface, and a horizontal force in the direction of motionD) a downward force of gravityA) a downward force of gravity and an upward force exerted by the surface
Answer:
the statements, the correct one is A
a downward force of gravity and an upward force exerted by the surface
Explanation:
When the disc is hit, a thrust force is exerted in the direction of movement, at the moment the disc moves this force loses contact and becomes zero.
When the movement is already established there are two main forces: gravity that acts downwards and the reaction force to the support of the disk called normal that acts upwards.
As it is not mentioned that there is friction, this force that opposes the movement is zero.
Analyzing the statements, the correct one is A
Which of the following is not a valid use of your driver's license?
O proof of your ability to operate a motor vehicle
O proof of your age
proof of your residency
O proof that you have liability insurance
NEXT QUESTION
In the state where I live, your driver's license is not a proof that you have liability insurance. You don't need liability insurance to get a driver's license, but you need it in order to operate a car that you own.
It may be different in the state where YOU live.
NEXT QUESTION
From the gravitational law, calculate the weight W (gravitational force with respect to the earth) of a 70 kg spacecraft traveling in a circular orbit 275 km above the earth's surface. Express W in Newtons and pounds.
Answer:
The value in Newton is [tex]W = 631.92 \ N[/tex]
The value in pounds is [tex]W = 142 \ lb[/tex]
Explanation:
From the question we are told that
The mass of the spacecraft is [tex]m = 70 \ kg[/tex]
The distance above the earth is [tex]d = 275 \ km = 275000 \ m[/tex]
Generally the gravitational force with respect to the earth is mathematically represented as
[tex]W = \frac{G * m * m_e}{ (d + r_e)^2}[/tex]
Here [tex]m_e[/tex] is the mass of earth with value [tex]m_e = 5.978 *10^{24} \ kg[/tex]
[tex]r_e[/tex] is the radius of the earth with value [tex]r_e = 6371 \ km = 6371000 \ m[/tex]
G is the gravitational constant with value [tex]G = 6.67 *10^{-11} \ m^3/ kg\cdot s^2[/tex]
So
[tex]W = \frac{ 6.67 *10^{-11} * 70 * 5.978 *10^{24}}{ (275000 + 6371000)^2}[/tex]
[tex]W = 631.92 \ N[/tex]
Converting to pounds
[tex]W = \frac{631.92 }{4.45}[/tex]
[tex]W = 142 \ lb[/tex]
The acceleration of a particle traveling along a straight line is
a=16s1/2 m/s2, where s is in meters.
If v = 0, s = 3 m when t = 0, determine the particle's velocity at s = 6 m.
Answer:
V= 14.2m/s
Explanation:
We know that acceleration= dv/dt
So 16m/s²=dv/ dt = v dv/ds
So this wil be
Integral of 16m/s² ds [at 2,2]= integral of v dv at[ 0, v]
So 16[s (3/2)/3/2] at ( s,3) = v²/2
At s= 6m
So v² = 64/3( 6^1.5-3^1.5)
= 14.2m/s
A fly enters through an open window and zooms around the room. In a Cartesian coordinate system with three axes along three edges of the room, the fly changes its position from point b (2.5 m, 2.0 m, 4.0 m) to point e (4.5 m, 3.0 m, 3.5 m). Find the scalar components of the flies displacement vector (in m).
Answer:
Explanation:
Displacement vector along x axes = 4.5 - 2.5 = 2 m
Displacement vector along y axes = 3 - 2 = 1 m
Displacement vector along z axis = 3.5- 4 = - 0.5 m
Displacement vector = 2 i + j - 0.5 k m
Common benefits of lower body endurance include improved
Answer:
Hearing, Vision and Metabolism.
in an equation f = l^2-d^2/4l the intercept is
Answer:
the intercept is the orgin (0,0)
Peter left Town A at 13:30 and travelled towards Town B at an
average speed of 40 mph. At 13:45, Philip left Town A for Town
B at an average speed of 30 mph. What was the distance
between them at 15:00?
Answer:
Explanation: From 13:30 to 15:00, it past: 1 h 30 mins = 1.5
Then, the distance covered by Peter: 40x1.5= 60 miles
From 13:45 to 15:00, it pasts; 1 h 15min =1.25
Then, the distance covered by Philip. 30 x 1.25 = 37.5 miles
Lastly, the distance between them: 60-37.5= 22.5 miles
So the answer is 22.5
Find the magnitude of the magnetic field ∣∣B⃗ (r)∣∣ inside the cylindrical resistor, where r is the distance from the axis of the cylinder, in terms of i, r, r0, l, and other given variables. You will also need π and μ0. Ignore fringing effects at the ends of the cylinder.
Answer:
The magnetic field inside the cylindrical resistor is [tex]\dfrac{\mu_{0}ir}{2\pir_{0}^2}[/tex]
Explanation:
Given that,
Distance from the axis of the cylinder = r
We need to calculate the magnetic field inside the cylindrical resistor
Using formula of magnetic field
[tex]\oint{\vec{B}\cdot\vec{dl}}=\mu_{0}i_{encl}[/tex]
[tex]B\cdot(2\pi r)=\mu_{0}\dfrac{i\pir^2}{\pi r_{0}^2}[/tex]
Where, r₀ = radius
r = distance
i = current
[tex]|\vec{B}(r)|=\dfrac{\mu_{0}ir}{2\pir_{0}^2}[/tex]
Hence, The magnetic field inside the cylindrical resistor is [tex]\dfrac{\mu_{0}ir}{2\pir_{0}^2}[/tex]
An engineer is designing a tire for heavy machinery which statement describes the clearest criterion for the solution
Answer:
I think B tell me if it's right
Explanation:
If an engineer is designing a tire for heavy machinery then a statement that describes the clearest criterion for the solution would be that it must function safely under the load of 4500 kg, therefore the correct answer is option C.
What is the mechanical advantage?Mechanical advantage is defined as a measure of the ratio of output force to input force in a system, It is used to analyze the forces in simple machines like levers and pulleys.
Mechanical advantage = output force(load) /input force (effort)
As given in the problem statement that an engineer is designing a tire for heavy machinery and we have to find the statement which describes the clearest criterion for the solution,
As he is designing heavy machinery that must be able to support a large amount of weight,
Thu, the best option that is satisfying the criteria is option C.
Learn more about Mechanical advantages, here
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Aa commercial advertising a diet pill says it is scientifically proven to help you lose weight. It is recommended by a doctor who observed that some of his patients lost weight after taking the pill for a week. Why is this claim considered pseudoscience
Answer:
no more than 10 pills a day depending on what type it is
Explanation:
A sidewalk has a length of 75.00m. How many inches is this? (Hint: you need to use two unit conversion fraction. 1 cm equals about 0.3937 inches)
Length = (75.00 m)
Length = (75 meter) x (3.28084 foot/meter) x (12 inch/foot)
Length = (75 x 3.28084 x 12) (meter-foot-inch / meter-foot)
Length = 2,952.76 inches
Write all the different ways you can think of that describe what it means to be healthy
Answer:
Eat more healthy foods. Workout and build your immune system.
Explanation:
Eat Healthy foods like Carrots, Apples, Bannas, Pears, and anything that deals with not much of any sugar. An example of unhealthy foods is Cakes, Chocolates, Candy, and more. Drink a lot of water.
What does it mean that a theory or model is workable?
PLEASEEEEEEEE HELP ME FAST
Answer:
model is viable if the assumptions that answer it are in accordance with the fundamental principles or laws of physics and if it gives conclusions that can be tested with experiments.
Explanation:
A model in physics must be verified by experiments that are carried out to measure the consequences derived from it.
A model is viable if the assumptions that answer it are in accordance with the fundamental principles or laws of physics and if it gives conclusions that can be tested with experiments. Models that meet these conditions are said to be viable
imagine imagining an imagination.
Answer:
We’re imagining imagining imagining an imagination...
A sinusoidal electromagnetic wave from a radio station passes perpendicularly through an open window that has area of 0.500 m2 . At the window, the electric field of the wave has an rms value 0.0600 V/m .
How much energy does this wave carry through the window during a 30.0-s commercial? Express your answer with the appropriate units.
Answer:
The energy of the wave is 1.435 x 10⁻⁴ J
Explanation:
Given;
area of the window, A = 0.5 m²
the rms value of the field, E = 0.06 V/m
The peak value of electric field is given by;
[tex]E_o = \sqrt{2} *E_{rms}\\\\E_o = \sqrt{2}*0.06\\\\E_o = 0.0849 \ V/m[/tex]
The average intensity of the wave is given by;
[tex]I_{avg} = \frac{c \epsilon_o E_o^2 }{2}\\\\I_{avg} = \frac{(3*10^8)( 8.85*10^{-12}) (0.0849)^2 }{2}\\\\I_{avg} = 9.569*10^{-6} \ W/m^2[/tex]
The average power of the wave is given by;
P = I x A
P = (9.569 x 10⁻⁶ W/m²) (0.5 m²)
P = 4.784 x 10⁻⁶ W
The energy of the wave is given by;
E = P x t
E = (4.784 x 10⁻⁶ W)(30 s)
E = 1.435 x 10⁻⁴ J
Therefore, the energy of the wave is 1.435 x 10⁻⁴ J
A bird flutters around in a tree in a path described by the dark line: Which vector represents the average velocity of the bird? Question 2 options:
Answer:
Displacement vector represents the average velocity of the bird.
Explanation:
Given that,
A bird flutters around in a tree in a path described by the dark line.
Suppose, given vectors
(a). Time, (b). Displacement, (c). speed, (d). distance
We know that,
Vector quantity :
Vector quantity has direction and magnitude.
Average velocity :
Average velocity is equal to the displacement divided by time.
In mathematically,
[tex]v=\dfrac{D}{t}[/tex]
Where, D = displacement
t = time
We need to find the vector which is represents the average velocity of the bird
Using given data
Average velocity of the bird shows the displacement over the time.
Displacement is the vector quantity.
Hence, Displacement vector represents the average velocity of the bird.
What line on a wheather map indicates áreas where the temperature is the same?
Answer:Isobars and isotherms
Explanation:
A car originally traveling at 30.0 m/s manages to brake for 5.0 seconds while traveling 125 m along a road. After those first 5.0 seconds, the brakes fail. After an additional 5.0 seconds it travels an additional 150 m further down the road. What was the magnitude of the acceleration of the car after the brakes failed
Answer:
The magnitude of the acceleration of the car after the brakes failed is 4 m/s²
Explanation:
The car was originally traveling at 30.0 m/s, that is
The initial velocity, [tex]u[/tex] = 30.0 m/s
The time spent while the car manages to brake is 5.0 seconds, that is
time, [tex]t[/tex] = 5.0 secs
and the distance traveled during this time is
distance, [tex]s[/tex] = 125 m
From one of the equations of kinematics for linear motion,
[tex]s = ut + \frac{1}{2}at^{2} \\[/tex]
Where [tex]a[/tex] is the acceleration
We can determine the deceleration of the car during the first 5.0 seconds
Hence,
From,
[tex]s = ut + \frac{1}{2}at^{2} \\[/tex]
[tex]125 = 30.0(5.0) + \frac{1}{2}(a)(5.0)^{2}[/tex]
[tex]125 =150.0 + 12.5a[/tex]
[tex]12.5a = 125 - 150.0[/tex]
[tex]12.5a = -25\\a = \frac{-25}{12.5}\[/tex]
[tex]a = - 2.0 m/s^{2}[/tex] (Negative sign indicates deceleration)
Now we will calculate the final velocity reached at this time
From,
[tex]v^{2} = u^{2} + 2as[/tex]
Where [tex]v[/tex] is the final velocity
[tex]v^{2} = 30.0^{2} + 2(-2.0)(125)\\v^{2} = 400\\v = \sqrt{400} \\v = 20 m/s \\[/tex]
This is the final velocity reached by the car during the first 5.0 seconds
Now, for the magnitude of the acceleration of the car after the brakes failed,
After the brakes failed,
it travels an additional 150 m further down the road, that is
s = 150m
an additional 5.0 seconds, that is
t = 5.0 seconds
Also, from
[tex]s = ut + \frac{1}{2}at^{2} \\[/tex]
The initial velocity here will be the final velocity for the first 5.0 seconds, that is,
u = 20 m/s
Hence,
[tex]s = ut + \frac{1}{2}at^{2} \\[/tex] becomes
[tex]150 = 20(5.0) + \frac{1}{2}(a)(5.0)^{2}[/tex]
[tex]150 = 100 + 12.5a\\12.5a = 150 - 100\\12.5a = 50\\a = \frac{50}{12.5} \\a = 4m/s^{2}[/tex]
Hence, the magnitude of the acceleration of the car after the brakes failed is 4 m/s²
How long did it take me to make this?
Answer:
Its according from what it is made with if wax it takes longer but if with a craft paper it takes lesser time if paper approximately 20 to 25 minutes
I point
Is the car's speed increasing or decreasing with time?
not enough information
decrease
increase
constant
Answer:
It's increasing with time
A 1.7 kg model airplane is flying north at 12.5 m/s initially, and 25 seconds later is observed heading 30 degrees west of north at 25 m/s. What is the magnitude of the average net force on the airplane during this time interval?
Answer:
Average net force = 0.62 N
Explanation:
We are given;
Mass; m = 1.7 kg
Initial velocity; u = 12.5 m/s
Final velocity; v = 25 m/s
time; t = 25 seconds
Now, we are told that the final velocity was 30° west of North. So, resolving this velocity along the horizontal gives;
v = 25 cos 30°
Now, using Newton's first equation of motion gives;
v = u + at
Where a is acceleration
Plugging in the relevant values gives;
25 cos 30° = 12.5 + 25a
21.6506 - 12.5 = 25a
a = (21.6506 - 12.5)/25
a = 0.3660 m/s²
Now, magnitude of the average net force would be; F = ma
F = 1.7 × 0.366
F ≈ 0.62 N
what is the difference between each distance traveled and displacement travled
Displacement is a vector magnitude that depends on the position of the body which is individualistic for the trajectory.
While, Distance is a scalar magnitude that measures over the trajectory.
an object is accelerating if it is moving____. circle all that apply.
Answer:
With changing speed and/or in a circle
What is the value of the radius of the following circle with an area of 154 cm2?
The area of ANY circle is (π) · (radius²).
So ...
(π) · (radius²) = 154 cm²
radius² = (154 cm²) / (π)
radius² = 49.02 cm²
radius = √(49.02 cm²)
radius = 7 cm
Answer:
[tex] \boxed{\sf Radius \ of \ circle \ (r) = 7 \ cm} [/tex]
Given:
Area of circle = 154 cm²
To Find:
Radius of circle (r)
Explanation:
[tex] \bold{Area \: of \: circle = \pi r^2}[/tex]
[tex] \sf \implies \pi {r}^{2} = 154 \\ \\ \sf \implies {r}^{2} = \frac{154}{\pi} \\ \\ \sf \implies {r}^{2} = \frac{154}{ \frac{22}{7} } \\ \\ \sf \implies {r}^{2} = \frac{154 \times 7}{22} \\ \\ \sf \implies {r}^{2} = \frac{1078}{22} \\ \\ \sf \implies {r}^{2} = 49 \\ \\ \sf \implies {r}^{2} = {7}^{2} \\ \\ \sf \implies r = \sqrt{ {7}^{2} } \\ \\ \sf \implies r = 7 \: cm[/tex]
Is the sinusoidal pattern on the string longer or shorter with a greater propagation velocity?
Answer:
Increase in velocity propagation would lead to a longer sinusoidal pattern.
Explanation:
The velocity of propagation has a relationship with the tension in a standing wave and is given by;
v = √(T/μ)
where:
μ is mass per unit length.
T is tension in string
For the sinusoidal pattern on the string to be longer or shorter, it means that the wavelength will be longer or shorter.
Now, relationship between wavelength and velocity and tension is;
v = λ/T
Where V is velocity of propagation, λ is wavelength and T is Tension.
So, λ = vT
From the earlier standing wave equation, we will see that if we increase the velocity, it means the Tension of the spring will increase as well.
Thus, from this wavelength equation, an increase in velocity means an increase in tension and which will in turn mean an increase in wavelength.
Therefore, an increase in velocity propagation means a longer sinusoidal pattern.