Answer:
A.) 1.3 seconds
B.) 0.42 m
Explanation:
A.) You are given the angle of projection to be 40 degrees and initial velocity of 20m/s.
At vertical component
U = Usin 40 that is,
U = 20sin40
Using the first equation of motion under gravity
V = U - gt
Let V = 0
0 = UsinØ - gt
gt = UsinØ
t = UsinØ/g
Where U = 20 m/s
Ø = 40 degree
g = 9.8 m/s^2
Substitutes all the parameters into the formula
t = 20sin40/9.8
t = 1.3 seconds
Total time of flight T = 2t
T = 2 × 1.3 = 2.6 s
B.) To calculate the maximum height,
You will use the formula
V^2 = U^2 - 2gH
At maximum height, V = 0
2gH = Usin^2Ø
H = Usin^2Ø/ 2g
Substitutes all the parameters into the formula
H = 20 sin^2(40) ÷ 2(9.8)
H = 8.2635/19.6
H = 0.42 m
If you try opening a door by pushing too close to the side where the hinges are, you may find it difficult to push open. Suppose you are trying to open a door that is 75 cm wide. (Hint: To solve this one, remember the example problem in the lesson about the MA of the broom). a. If you push on the door at a point 15 cm away from the hinges, what is the mechanical advantage? b. What is the best mechanical advantage that you can obtain for any door that you simply push open? Your answer:
Answer:
a) Mechanical advantage is 0.2
b) maximum obtainable mechanical advantage is 1
Explanation:
The opening of the door is only possible when a force is used to push the door, by generating a torque on the door around the hinge.
Since the door is 75 cm wide, torque generated will be the product of the force applied and the width of the door.
torque = F x 75 = 75F
If the door was pushed at point on the door 15 cm from the hinges, the torque that will be generated will be
torque = F x 15 = 15F
a)The mechanical advantage MA is therefore
MA = 15/75 = 0.2
b) The best mechanical advantage that can be obtained from when you simply push it open is 1
From the case above, if we assume we push it at its maximum width from the hinge, then
MA = 75/75 = 1
3. How do we measure the average kinetic motion of molecules in a solution?
A ball is tied to the end of a length of string. A student holds one end of the string and whirls it so the ball travels in a vertical circle. First she whirls the ball at a very fast speed, and then she very gradually lowers the speed. Where is the ball most likely to be when the string begins to sag?
Answer:
The top of the circle
Explanation:
At the top of the circle, there are two forces pulling the ball towards the center of the circle: weight and tension.
∑F = ma
mg + T = mv²/r
As v goes down, T also goes down, until it eventually reaches 0.
At the bottom of the circle, weight is pulling down, or away from the center of the circle. Sum of the forces:
∑F = ma
T − mg = mv²/r
As v goes down, T also goes down. However, even at v=0, T cannot be less than mg.
What causes the particles within the nucleus of an atom to bond together? Question 12 options: electromagnetism gravity weak nuclear force strong nuclear force
Answer:
Strong nuclear force
Explanation:
The particles in the atom's nucleus bond together because there is a strong nuclear force between the protons and neutrons that attracts them to each other and binds together the nucleus.
Suppose the initial position of an object is zero, the starting velocity is 3 m/s and the final velocity was 10 m/s. The object moves with constant acceleration. Which part of a velocity vs. time graph can be used to calculate the displacement of the object?
the area of the rectangle under the line
the area of the rectangle above the line
the area of the rectangle plus the area of the triangle under the line
the area of the rectangle plus the area of the triangle above the line
Answer:
The area of the rectangle plus the area of the triangle under the line
Explanation:
In this case, the object moves with constant acceleration. Initial speed of the object is 0.
Equation of kinematics :
v = u +at
v = at
v is directly proportional to time. If means that the graph is straight line passing through origin. We know that area under v-t graph gives displacement. So, the correct option is (c).
Answer:
c) the area of the rectangle plus the area of the triangle under the line
Explanation:
edge2021
48:09 Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? The first law describes how thermal energy is conserved but not the direction it moves. The first law describes the direction thermal energy moves but not how it is conserved. The first law describes how thermal energy can be created but not how it can be destroyed. The first law describes how thermal energy can be destroyed but not how it can be created.
Answer:
A). The first law describes how thermal energy is conserved but not the direction it moves.
Explanation:
Thermodynamics is demonstrated as the branch of physics that deals with the associations or relationships between heat and other energy forms like mechanical, chemical, and electrical).
As per the question, the first law discusses that heat is a kind or form of energy and thus, processes associated with thermodynamics are subject to energy conservation principle. Therefore, heat energy can neither be destroyed nor created but rather transferred to one place to another and converted to and from other energy forms.
Thus, the first law of thermodynamics is distinct from the second law as 'the former describes how thermal energy can be conserved to and from other forms of energy and not the direction in which it moves' while the second law focuses on entropy. Therefore, option A is the correct answer.
The first law of thermodynamics describes the conservation of heat energy but not the direction it moves. Option A correct.
First law of Thermodynamics:
It states that the energy cannot be produced or destroyed it just change from one form to another.
Heat is a form of energy and thus, follow the energy conservation principle. So, heat can be change into mechanical energy.
The second law describe the direction of movement of heat.
Therefore, option A is the correct answer.
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If an electromagnetic wave has a frequency of 4.5 x 1018 Hz, what is its
wavelength? Use î=”. The speed of light is 3 * 108 m/s.
A. 1.5 x 10-26
B. 6.7 x 1026 m
C. 1.5 x 10-10 m
D. 6.7 * 10-11 m
Answer:
Wavelength of electromagnetic wave = 6.7 × 10⁻¹¹
Explanation:
Given:
Frequency of electromagnetic wave = 4.5 × 10¹⁸ Hz
Speed of light = 3 × 10⁸ m/s
Find:
Wavelength of electromagnetic wave
Computation:
⇒ Wavelength = Speed of light / Frequency
⇒ Wavelength of electromagnetic wave = 3 × 10⁸ / 4.5 × 10¹⁸
⇒ Wavelength of electromagnetic wave = 0.67 × 10⁻¹⁰
Wavelength of electromagnetic wave = 6.7 × 10⁻¹¹
A deep-space satellite is sent to orbit a distant planet with unknown mass. On
arrival, the satellite begins its orbit and measures a gravitational pull from the
planet of 620 N. If the satellite has a mass of 450 kg and orbits the planet at a
radius of 4.0 x 10^6m, what is the approximate mass of the planet?(recall that G=6.7x10^-11 N•m2/kg^2.)
Answer:
The mass of the planet is [tex]3.29\times 10^{23}\ kg[/tex].
Explanation:
Given that,
The gravitational pull on the planet is 620 N
Mass of a satellite is, m₁ = 450 kg
Radius of a planet is [tex]4\times 10^6\ m[/tex]
We need to find the mass of the planet. Gravitational force is given by :
[tex]F=\dfrac{Gm_1m_2}{r^2}[/tex][tex]m_2[/tex] is the mass of the planet
[tex]m_2=\dfrac{Fr^2}{Gm_1}\\\\m_2=\dfrac{620\times (4\times 10^6)^2}{6.7\times 10^{-11}\times 450}\\\\m_2=3.29\times 10^{23}\ kg[/tex]
So, the mass of the planet is [tex]3.29\times 10^{23}\ kg[/tex].
Which option describes a phase change
Answer:
b. Gasloine evaporating into the air
I tryed to answer
Which shows a decrease in fluid pressure? A. Water in a creek slows down as it enters a slow-moving river. B. Oxygen is compressed as it is put into a pressurized tank. C. A river speeds up when it moves into a narrower channel. D. A fan is turned on high speed to low speed.
Answer:
Option D.
A fan is turned from high speed to low speed.
Explanation:
It is important to note that air is also a fluid.
In a system, static pressure of air increases with the speed of rotation of the fan. This is because when the speed of the fan is increased, the force with which it is pushing the air molecules is increased. Since pressure is a relationship between force and area, the pressure of the air molecules will be increased.
Conversely, when the speed of the fan is reduced, the priming force on the air molecules will be reduced, hence the pressure of the air will drop.
This makes option D the correct option
Answer:
A
Explanation
Becasue the water level is decreasing
Please help me in this question!! There is NO picture fo this question! In a physics lab, 0.30 kg puck A, moving at 5.0 m/s [W], undergoes a collision with 0.40 kg puck B, which is initially at rest. Puck A moves off at 4.2 m/s [W 30° N]. Find the final velocity of puck B.
I have a test tomorrow and I can't find the definitions in my book so can you pls help me study by answering the following question? thnx! I will also mark the brainliest.
Answer:
See explanation
Explanation:
An element is a substance that cannot be chemically converted to another substance or broken down chemically into other substances.
Elements are represented by symbols. The symbol of an element may be the first one or two letters from its English or Latin name. For instance, the symbol of nitrogen is N. This symbol was derived from the first letter of its English name. The symbol for sodium is Na. This was derived from the first two letters of its Latin name, Natrium.
The periodic table is divided into horizontal rows called periods and vertical columns called groups. All members of the same period have the same number of electron shells while all members of the same group have the same number of valence electrons.
Metals are found towards the left hand side of the periodic table while non metals are found towards the right hand side of the periodic table. Metals looses electrons easily while nonmetals accepts electrons easily. Metals are good conductors of heat and electricity while non metals are poor conductors of heat and electricity.Metalloids have properties intermediate between those of metals and non metals and are found at the boarder line between metals and non metals in the periodic table. Metalloids include; silicon, boron, germanium, etc. The electrical conductivity of metalloids increases with temperature while the electrical conductivity of metals decreases with temperature.
What do you feel when you hold your hand near a glowing fire or an electric heater?
Answer:
The heats radiation.
Explanation:
When placing your hand close to a fire or electric heater, you can feel the warmth of the object. Pull your hand away from it, it'll be cooler.
Answer:
The radiation of heat
Explanation:
At which point does the planet have the least gravitational force acting on it?
Answer:
At which point does the planet have the least gravitational force acting on it?
Explanation:
In an elliptical orbit, when a planet is at its furthest point from the Sun, it is under the least amount of gravity, meaning that the force of gravity is strongest when it is closest.
Answer:
Point A
Explanation:
Recall that gravitational force is inversely proportional to the square of the distance between the 2 objects.
This means that the farther away the objects are from each other, the lesser their gravitational interaction will be.
In this case we can see that Point A is furthest away from the star, hence this will be the location with the least gravitational force from the star.
Which of the following elements are in this chemical reaction: Zn (s) + HCl (9) → ZnCl2 (s) + H2 ?
Multiple answers
Α. Η
B. CI
C. Zn
D. nCI
Answer:
A, B and C
Explanation:
You are given the chemical equation.
The chemical reaction:
Zn (s) + HCl (9) → ZnCl2 (s) + H2
The elements involved are
Zinc, hydrogen and Chlorine.
That is, H, Cl and Zn
The Zinc is in solid form
While hydrochloric acid is in aqueous form.
The correct answers are A ,B and C
Ethan made a diagram to compare examples of the first and second laws of thermodynamics. What belongs in the areas marked X and Y?
X: The internal energy of a piston system increases
as heat is added and rises to a cool area
Y: As thermal energy is added to a container, some
of the energy is lost to the environment
X: As thermal energy is added to a container, some
of the energy is lost to the environment
Y: The internal energy of a piston system increases
as heat is added and rises to a cool area
X: A cold spoon placed in hot liquid gets warmer
Y: Thermal energy is converted to light energy
X: Thermal energy is converted to light energy
Y: A cold spoon placed in hot liquid gets warmer
Answer:
D: X: Thermal energy is converted to light energy
Y: A cold spoon placed in hot liquid gets warmer
Explanation:
j took the quiz
The first and second laws of thermodynamics are used to describe the process of heat transfer.
What are the laws of thermodynamics?The laws of thermodynamics are laws that show the transfer of heat energy there are three laws of thermodynamics that guide heat transfer.
From the statements of the first and second laws of thermodynamics, the statements that fit into the circles are;
X: Thermal energy is converted to light energy
Y: A cold spoon placed in hot liquid gets warmer
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What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m? What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
Answer:
a) What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m?
5m/s
b) What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
40Hz
Explanation:
a) What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m?
Wave speed(v) = Frequency(f) × Wavelength (λ)
= 50Hz × 0.10m
=5m/s
b) What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
The formula for Frequency when given wave speed and wave length = Wave speed/ wave length
f = v/λ
Frequency = 20m/s ÷ 0.50m
Frequency = 40Hz
Answer:
40 Hz
Explanation:
Which of the following is an example of a primary source?
A. A dictionary definition of a science term
B. An article written by a scientist
C. A textbook written by a scientist
D. An encyclopedia entry about an experiment
Answer:
i think its no c.
a textbook written by a scientist. because its a first hand data.
An article written by a scientist is an example of a primary source. The correct option is option (B).
A primary source refers to an original, firsthand account or direct evidence of an event, topic, or research. It is created by individuals who directly participated in or witnessed the subject matter. An article written by a scientist would be considered a primary source as it typically presents the researcher's own observations, experiments, methodology, and conclusions.
It provides direct access to the original research and findings, making it an important source for scholarly and scientific purposes. In contrast, options A, C, and D are secondary sources that provide interpretations or summaries of information from primary sources.
Therefore, The correct option is an option (B).
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plz help!!!
urgent!!
will give the brainliest!!!
Answer: Find the answer in the explanation.
Explanation:
I.) A piece of wire at room temperature.
The resistance of a piece of wire at room temperature is independent of both current and the voltage because it is an Ohmic component.
II.) Filament bulb
The filament wire in the filament bulb does not obey Ohms law.
For very small currents and voltage, the graph is roughly a straight line. At higher voltages, the line starts to curve.
III.) A diode is any component that allows electric current in only one direction. The resistance of a diode depends on the potential difference across it. Therefore, it does not obey Ohms law. It is a non-Ohmic component.
Find the attached files for the figures
Rosa records the distance that a toy car rolls and the time it takes to cover the distance. What scientific practice is this? collecting data asking a question providing explanations communicating results
Answer:
collecting data
Explanation:
Data collection refers to a systematic method for gathering and analyzing information from a number of sources in order to provide a complete and reliable image of a subject region. The collection of data helps an individual or organization to answer specific questions, determine outcomes, and predicting future possibilities and outcomes. As per the question, rosa is collecting data about the distance and time of her toy car intrigued by the scientific query.
Answer:
A : Data
Explanation:
I’m doing the exam
How is a voltmeter used in a circuit?
A. It is connected in series and measures current.
B. It is connected in parallel and measures potential difference.
C. It is connected in parallel and measures current.
D. It is connected in series and measures potential difference.
Answer:
Explanation:
A voltmeter is usually connected in parallel with a part of a complete circuit. The meter itself is connected in series to a very high resistance so that the amount of current drained is very tiny.
So you see, you could answer this in two ways, but since you are asking a question at a very beginning level, I think the answer should be
B
because voltmeters are made to measure potential difference and they are placed in parallel to the part measured. How it works is interesting but is not really part of the question.
Answer:
B. It is connected in parallel and measures potential difference.
Explanation:
A voltmeter is connected in parallel.
A voltmeter is used for measuring the electrical potential difference between two points in an electric circuit.
A 51-kg woman runs up a vertical flight of stairs in 5.0 s. Her net upward displacement is 5.0 m. Approximately, what average power did the woman exert while she was running?
Answer:
The average power the woman exerts is 0.5 kW
Explanation:
We note that power, P = The rate at which work is done = Work/Time
Work = Energy
The total work done is the potential energy gained which is the energy due to vertical displacement
Given that the vertical displacement = 5.0 m, we have
Total work done = Potential energy gained = Mass, m × Acceleration due to gravity, g × Vertical height, h
m = 51 kg
g = Constant = 9.81 m/s²
h = 5.0 m
Also, time, t = 5.0 s
Total work done = 51 kg × 9.81 m/s²× 5 m = 2501.55 kg·m²/s² = 2501.55 J
P = 2501.55 J/(5 s) = 500.31 J/s = 500.31 W ≈ 500 W = 0.5 kW.
Which explains the operation of a hydraulic lift system? A. Archimedes' principle B. Pascal's principle C. Newton's principle D. Bernoulli's principle
Answer: B. Pascal's principle
This is the idea where you compress a liquid on one end of a tube (more or less), and the liquid's pressure is transmitted to the other end to help lift a heavy object. Often the compressing force is downward to take advantage of gravity.
An object moving north with an initial velocity of 14 m/s accelerates 5 m/s2 for 20 seconds. What is the final velocity of the object? 39 m/s 90 m/s 114 m/s 414 m/s
Answer:
Final velocity of the object(v) = 114 m/s
Explanation:
Given:
Initial velocity (u) = 14 m/s
Accelerates (a) = 5 m/s²
Time taken = 20 seconds
Find:
Final velocity of the object(v) = ?
Computation:
According to 1st law of motion.
⇒ v = u +at
⇒ v = 14 + (5)(20)
⇒ v = 14 + 100
⇒ v = 114 m/s
Final velocity of the object(v) = 114 m/s
Priscilla is driving her car on a busy street and Harvey passes her on his motorcycle. What will happen to the sound from his motorcycle after it
passes her car?
Answer:
what will happen to the sound is the wavelength increases thus frequency decreases so the sound decreases as he move away from her car..
In general, the the string or air column of a musical instrument is, the more harmonics are generated.
Answer:
In general, the LONGER the string or air column of a musical instrument is, the more harmonics are generated.
What would be the mass of the ball described in the photo?
Answer:
- Mass of the ball = 45 Kg
Explanation:
velocity attained by the ball:
Distance/time= 54/9 = 6m/s (meter per sec)
As work done on ball = distance * force applied
= 54*15
= 810 J ----------------- (i)
acc. to the conservation of energy:
work done = kinetic energy + potential energy
= 1/2*m*[tex]v^{2}[/tex] + 0(as object is on ground)
= 1/2*m*[tex]6^{2}[/tex]
= 1/2*36*m
= 18*m ------------------- (ii)
∵,(i) =(ii)
18*m = 810
m=810/18
m= 45kg
A 15.0 cm object is 12.0 cm from a convex mirror that has a focal length of -6.0 cm. What is the height of the image produced by the mirror? A. –5.0 cm B. 7.5 cm C. -7.5 cm D. 5.0 cm
Answer: D. 5cm
Explanation:
Given the following :
Focal length (f) = - 6.0 cm
Height of object = 15.0cm
Distance of object from mirror (u) = 12.0cm
Height of image produced by the mirror =?
Firstly, we calculate the distance of the image from the mirror.
Using the mirror formula
1/f = 1/u + 1/v
1/v = 1/f - 1/u
1/v = 1/-6 - 1/12
1/v = - 1/6 - 1/12
1/v = (- 2 - 1) / 12
1/v = - 3 / 12
v = 12 / - 3
v = - 4
Using the relation :
(Image height / object height) = (- image distance / object distance)
Image height / 15 = - (-4) / 12
Image height / 15 = 4 / 12
Image height = (15 × 4) / 12
Image height = 60 / 12
Image height = 5cm
Answer:
D. 5 cm
Explanation:got it right
A lens is used to make an image of magnification -1.50. The image is 30.0 cm from the lens. What is the object’s distance (unit=cm)? PLS HELP
Answer: 20cm
Explanation:
Given the following data:
Magnification of image = - 1.50
Distance of image from the lens = 30.0cm
The Magnification of an image is the ratio of the image distance from the lens and the object distance from the lens.
Mathematically,
Magnification(M) = - (image distance (di) / object distance (do))
M = - (di/do)
-1.50 = - (30/do)
do = 30 / 1.5
do = 20 cm
Object is placed at a distance of 20cm from the lens.
A 24.8 cm tall object is placed in front of a lens, which creates a -3.09 cm tall image. If the object is 37.5 cm from the lens, what is the image distance? pls help
Answer:
v = 4.67 m
Explanation:
It is given that,
Height of the object is 24.8 cm
Height of the formed image is -3.09 cm
Object distance is 37.5 cm, it is negative always
We need to find the image distance. Let v is the image distance. Magnification of an object is given by the formula as follows :
[tex]\dfrac{h'}{h}=\dfrac{v}{u}\\\\v=\dfrac{uh'}{h}\\\\v=\dfrac{-37.5\times (-3.09)}{24.8}\\\\v=4.67\ m[/tex]
So, the image is formed at a distance of 4.67 m.