Scalar quantity are physical quantities that have just magnitude, not direction.
It is always positive.Examples: Speed, distanceFrom laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What is the receding speed of the star? c = 3x10^5 km/s
Answer:
[tex]v=-4.93\times 10^{5}~m/s[/tex] [negative sign denotes that it is moving away]
Explanation:
Actual wavelength of hydrogen spectral lines, [tex]\lambda=121.6~nm[/tex]
Apparent wavelength of hydrogen spectral lines from a star, [tex]\lambda'=121.8~nm[/tex]
So, shift in wavelength:
[tex]\Delta \lambda=\lambda'-\lambda[/tex]
[tex]\Delta \lambda=121.8-121.6[/tex]
[tex]\Delta \lambda=0.2~nm[/tex]
Using Doppler's shift:
[tex]\frac{\Delta \lambda}{\lambda} =-\frac{v}{c}[/tex]
[tex]\frac{0.2}{121.6} =-\frac{v}{3\times 10^8}[/tex]
[tex]v=-4.93\times 10^{5}~m/s[/tex] [negative sign denotes that it is moving away]
1. A plane flying a triangular patter flies 150 km[N], then 400 km(E). What is the total displacement of the
plane after these two legs? {4}
2. Ken and Susie are standing together. Ken walks 10 m (N) and then 15 m [W]. Susie walks 25 m [E] and
then 30 m [S]. What is the displacement from Ken to Susie? {5}
3. Students are performing an experiment for their physics class and are testing their predictions for
projectile motion. They set up a system so that a beanbag is launched horizontally off one of their
desks with an initial speed of 4.2 m/s. They measure the height of the desk to be 1.3 m.
a. What is the time of flight for the beanbag? {3}
b. What is the range for the beanbag? {2}
4. A historical society is testing an old cannon on the top of an old fort that has rusted and can only be
fired horizontally. They perform a few test fires of the cannon and measure the time of flight to be
3.78 s. How high is the hill? {3}
Answer:
1. The displacement is 427.2 km.
Explanation:
1. A = 150 km North
B = 400 km East
The net displacement is given by
[tex]R =\sqrt{400^2 + 150^2 }\\\\R = 427.2 km[/tex]
What is the name of the part of the wave that is labeled -
answer: amplitude
the ones who have to watch the video
Answer:
amplitude
Explanation:
sound travel and it amplifies
asset question.....only answers otherwise u will be reported
Answer:
C. 24 hrs
Explanation:
it takes the earth 24 hrs to make one full revolution.
The ability of a metal to react with air and water is a
property.
O chemical, physical, respectively
O physical, chemical, respectively
o physical, physical, respectively
O chemical, chemical, respectively
[tex]\bold{{Answer}}[/tex]
O physical, chemical, respectively
please buddy correct me if im wrong
The ability of a metal to react with air and water is a chemical, chemical, respectively property
What is a chemical change?A chemical change occur when the substance's composition is changed or when bonds are broken and new ones are forms a chemical change occur .
When a metal burn in air or react with air it form metal oxide and when metal react with water it forms oxides or hydroxides and release hydrogen gas . In both the cases change in composition is taking place . hence , bot are chemical reactions
correct answer is O chemical, chemical, respectively
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A uniform meter rule of mass 10g is balanced on a knife edge placed at 45cm mark. Calculate the distance of a mass 25g from the pivot
Answer:
2 cm.
Explanation:
Please see attached photo for diagram.
In the attached photo, y is the distance from the pivot to which the 25 g is placed.
The value of y can be obtained as follow:
Clockwise moment = 5 × 10
Anticlock wise moment = y × 25
Anticlock wise moment = Clockwise moment
y × 25 = 5 × 10
y × 25 = 50
Divide both side by 25
y = 50/25
y = 2 cm
Thus, the distance is 2 cm
help me do the c.....
yup they r equal as mentioned above is equal magnitude and direction! so they r totally equal.
as one vector has 2 things which is used to define it ->
Magnitudedirectionso if both r equal then both vectors r equal vectors
What is the enthalpy change, AH, for this reaction? Show your work to receive full credit. URGENT PICTURE INCLUDED !!!
Answer:
150 kJ
Explanation:
Applying,
ΔH = Energy level of Product(E') - Energy level of reactant(E)
Where ΔH = enthalpy change, E' and E = energy level of the product and the reactant respectively
ΔH = E'-E............. Equation 1
From the diagram,
Given: E' = 200 kJ, E = 50 kJ
Substitute these values into equation 1
ΔH = 200-50
ΔH = 150 kJ
Hence the enthalpy change for the reaction is 150 kJ
what is the angular speed w of the system immediately after the collision in terms f the sstem parameters and I
Answer: hello some part of your question is missing attached below is the missing detail
answer :
wf = M( v cos∅ )D / I
Explanation:
The Angular speed wf of the system after collision in terms of the system parameters and I can be expressed as
considering angular momentum conservation
Li = Lf
M( v cos∅ ) D = ( ML^2 / 3 + mD^2 ) wf
where ; ( ML^2 / 3 + mD^2 ) = I ( Inertia )
In terms of system parameters and I
wf = M( v cos∅ )D / I
Two objects, one with a mass of and the other with a force of 30.0kg experience a gravitational force of attraction of 7.50 * 10^- 8 N how far apart are centers of mass?
Answer:
Explanation:
The formula for this is
[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] where F is the gravitational force, G is the gravitational constant, m1 is the mass of one object and m2 is the mass of the other object. We are looking for r, the distance between the centers of their masses.
Filling in:
[tex]7.5*10^{-8}=\frac{6.67*10^{-11}(90.0)(30.0)}{r^2}[/tex] and moving things around to solve for r:
[tex]r=\sqrt{\frac{6.67*10^{-11}(90.0)(30.0)}{7.5*10^{-8}} }[/tex] Doing all that and rounding to the 3 sig fig's you need gives us a distance of 1.55 m
A child who is swimming toward shore at 0.78 m/s sees shark and picks up his speed
to 1.89 m/s. He covers 17.5 m until he lands on shore. What was his acceleration?
Answer:
0.085m/s²
Explanation:
Use v²=v0²+2a(d)
solve for a
v²-v0²/2d=a
Plug in givens
1.89²-0.78²/2*17.5=a
Plug into calculator
a=0.085m/s²
01:28:29
What type of relationship occurs when two variables both increase or decrease together?
O an inverse relationship
O a positive relationship
a direct relationship
O an indirect relationship
Answer:
an inverse relationship
Do the data for the first part of the experiment support or
refute the first hypothesis? Be sure to explain your
answer and include how the variables changed in the
first part of the experiment.
Mechanical equivalent of heat
Answer:
Sample Response: The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.
Explanation:
this the sample response from ED mechanical equivalent of heat lab.
Answer:
Sample response:
Explanation:
The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.
What is the name of the Egyptian sun god, usually depicted as a hawk-headed man with a solar disk and cobra on his head
Answer: Re-Horakhty
Explanation:
He has a human body and a falcon head, he has a crown in form of a disk with a cobra on his head. Ra-Horakhty was thought of as the god of the rising sun.
It is easier to lift the same load by using three pulley system than by using two-pulley system. why give reason.
Logic behind is lies behind the mechanical advantage of the provided bt the Pulley system.
as if we calculate the mechanical advantage of the 2 Pulley system we will have the value 2
And if we will calculate the mechanical advantage of the 3 pulley system then we will get the value of 3
so due to extra mechanical advantage we feel it easy to move with 3 pulley system then 2 Pulley system
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what is energy
and how it works?
Answer:
Energy is defined as the ability to do work.
Explanation:
Energy is a property that must be transferred to a body to perform work on the body. Energy can be found in many things and can take different forms.Energy is never lost, but it can be converted from one form to another.Fossil fuels are the largest sources of energy for energy generation.Ali while driving to school computes the average speed for his trip to be 20km/hr on his return trip along the same route. There is less traffic and average speed is 30km/hr. What is the average speed for Ali's trip?
Answer:
25 km/hr
Explanation:
Since Ali's average speed for his trip to school is u = 20 km/hr and his average speed for the return trip to back home from school is v = 30 km/hr, thus his total average speed for the journey is thus V = (initial average speed + final average speed)/2 = (u + v)/2
Substituting the values of the variables into the equation, we have
V = (u + v)/2
V = (20 km/hr + 30 km/hr)/2
V = 50 km/hr/2
V = 25 km/hr
So, the average speed for Ali's trip is 25 km/hr
Why are dark matter and dark energy described as dark
Dark matter and dark energy described as dark because of its no interaction with electromagnetic field.
Why are dark matter and dark energy described as dark?
Dark matter is called "dark" because it does not interact with the electromagnetic field. This means that it does not absorb, reflect, or emit electromagnetic radiation and therefore, it is difficult to detect.
So we can conclude that dark matter and dark energy described as dark because of its no interaction with electromagnetic field like dark substances.
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Dark matter and dark energy are described as dark because it doesn't seem to interact with the electromagnetic field.
What is the matter?The matter is a material that fills space and has inertia. Modern physics states that matter is made up of several kinds of particles, each of which has a mass and size.
The electron, proton, and neutron are three of the most well-known instances of material particles. Atoms are made up of combinations of these particles.
Dark matter is so-called because it doesn't seem to interact with the electromagnetic field.
This means it doesn't generate electromagnetic radiation like light or absorb electromagnetic radiation as it does. As a result, it is hard to detect.
Hence, dark matter and dark energy are described as dark.
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The search for black holes involves searching for The search for black holes involves searching for Group of answer choices single stars that emit large amounts of X-rays. a stellar core greater than 3 solar masses large spherical regions from which no light is detected. pulsars with periods less than one millisecond. pulsars that are orbited by planets.
Answer:
Large spherical regions from which no light is detected
Explanation:
A black hole is an object that has an extremely high density such that it possesses very powerful gravitational force that prevents the escape of all objects including light from it, and consumes nearby objects.
Due to the power of the gravitational force of a black hole, at the center, objects are infinitesimally compressed resulting in the inapplicability of the concept of space and time and the location is known as a singularity
Therefore, the search for black holes involves searching for large spherical regions from which no light is detected.
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10mls in 15 the car reaches a speed if 15 MLS in55 which has the greater acceleration the car or the bicycle
Complete question is;
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10m/s in 15 s, the car reaches a speed of 15 m/s in 55 s. which has the greater acceleration the car or the bicycle.
Answer:
The bicycle has the greater acceleration.
Explanation:
Cyclist reaches a top speed of 10m/s in 15 s.
Formula for acceleration here is;
a = v/t
a = 10/15
a = 0.67 m/s²
Car reaches a speed of 15 m/s in 55 s.
Thus;
a = 15/55
a = 0.27 m/s²
From the 2 acceleration values gotten, we can say that;
The bicycle has the greater acceleration.
A student sects a leaf of length 7.2 cm to draw. Her drawing is 28.8 cm in length. What is the magnification of the drawing?
a) x4
b) x207.36
c) x0.25
d) x36
Answer:
A) x4
Explanation:
Magnification is equal to image size divided by the actual size, or M = I/A.
The image size is the student's drawing, which is 28.8 cm, and the actual size is 7.2 cm. Divide them, and cancel out the units, and you should get:
28.8 cm/7.2 cm = 4
How can one form of energy be transferred into another.
Energy can be transferred mechanically through the movement of the parts in machines, and when the motion or position of an object changes. Sound waves and seismic waves (formed during earthquakes) are mechanical waves that transfer energy through materials and from place to place.
Hope This Helps :)
a car is travelling at 36 km per hour if its velocity increases to 72 km per hour in 5 seconds then find the acceleration of car in SI unit
Answer:
36 km /h means 10 m/s. Increase in speed is 10m/s in 5 s . Acceleration is ( 10/5 ) = 2 m/s^ 2.
a= 2m/s²
Explanation:
U=36km/h
V=72km/h
T=5s
Conversion of Km to m and H to s
1km = 1000m
36km=36×1000 = 36000m
1H = 3600s
For U, 36000/3600
=10m/s
For V,
72km= 72×1000 =72000
72000/3600
20m/s
a=(V-U)/T
a=(20-10)/5
a= 10/5
a= 2m/s²
A car travelling at 10ms ,acceleration uniformly at 2ms what will be its velocity after 5s?
[tex]we \: know \: that \\ acceleration = \frac{(final \: velocity - initial \: velocity)}{time} \\ = > a = \frac{(v - u)}{t} \\ = > 2m {s}^{ - 2} = \frac{{(v - 10m {s}^{ - 1} })}{5s} \\ = > 2m {s}^{ - 2} \times 5s = v - 10m {s}^{ - 1} \\ = > 10m {s}^{ - 1} = v - 10m {s}^{ - 1} \\ = > 10m {s}^{ - 1} + 10m {s}^{ - 1} = v \\ = > 20m {s}^{ - 1} = v \\ = > 20m {s}^{ - 1} = initial \: velocity[/tex]
Hope it helps!!
Thanks!!
Answer:
20 ms
Explanation:
You know
acceleration=2ms initial Velocity=10ms Time=5s
We are finding Final V
Use the equation Final v = (a x t) + initial v
2 x 5 = 10
10 + 10 = 20
If you are driving 90 km/hkm/h along a straight road and you look to the side for 2.8 ss , how far do you travel during this inattentive period
Answer:
Distance = 70 meters
Explanation:
Given the following data;
Speed = 90 km/h
Time = 2.8 seconds
Conversion:
90 km/h to meters per seconds = 90 * 1000/3600 = 90000/3600 = 25 m/s
To find the distance covered during this inattentive period;
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 distance the subject of formula, we have;
[tex] Distance = speed * time [/tex]
Substituting into the above formula, we have;
[tex] Distance = 25 * 2.8 [/tex]
Distance = 70 meters
What is the magnitude of the electric field at a point 0.0055 m from a 0.0025
C charge?
kg
Use E = and k=9.00 x 10 N.m²/C2.
O A. 7.4 x 1011 N
O B. 2.0 x 1010 N
O C. 4.1 x 10°N
OD. 7.9 x 1012 N
Answer:
Explanation:
The equation for the electric field is
[tex]E=\frac{kQ}{r^2}[/tex] so filling in:
[tex]E=\frac{9.00*10^9(.0025)}{(.0055)^2}[/tex] which in the end gives you
E = 7.4 × 10¹¹, choice A
Which component of weight is cause for S.H.M of bob simple pendulum
Explanation:
The Simple Pendulum. A simple pendulum is defined to have a point mass, also known as the pendulum bob, which is suspended from a string of length L with negligible mass ((Figure)). Here, the only forces acting on the bob are the force of gravity (i.e., the weight of the bob) and tension from the string.
hope it helps you
convert the following as instructed
67 kg into gram
explain step by step
please reply quickly its urgent
Answer:
1kg = 1000g
67kg therefore would be equal to
67 x 1000 = 67,000g = 6.7 x 10⁴g.
1. Use a micrometer to find the thickness of the foil you used. Do your data confirm the measured thickness? Determine the percentage difference between the measured thickness and the thickness you found in your experiment.
Answer:
Yes.
Explanation:
Yes, my data confirm the measured thickness because the micrometer measure precise thickness of any object. If the same instrument and right method is used for the measurement of the thickness of the foil then there is zero difference occur between the measured thickness and the thickness in your experiment so using right method can reduce or eliminate the difference between the measured thickness and the thickness in experiment.
6. An object is fired from the gound at 275 m/s at an angle of 55° N of E.
a. How far away did the object first hit the ground?
b. what is the maximum height that the object reaches?
there u go fella hope u understood