Answer:
Explanation:
Conservation of momentum
Let's say the first child was headed north
North momentum
75(0) + 20(2) + 15(3sin45) = (75 + 20 + 15)vn
vn = 0.6529 m/s
East momentum
75(0) + 20(0) + 15(3cos45) = (75 + 20 + 15)ve
ve = 0.28927 m/s
θ = arctan(0.28927/0.6529)
θ = 23.896...
θ = 24° east of north
Give an example of intense aerobics activity. Prompt must be accurate.
Answer:
Explanation:
An example of an intense aerobic activity would be running/ sprinting sprinting targets six specific muscle groups: hamstrings, quadriceps, glutes, hips, abdominals and calves. Sprinting is a total body workout featuring short, high-intensity repetitions and long, easy recoveries.
A baseball player notices the ball when it is 3.4 m above the
ground, traveling at 4.4 m/s. He wants to make the catch when
the ball is 1.5 m above the ground, how long does it take to reach
his glove?
Find the distance the ball travels:
3.4 meters - 1.5 meters = 1.9 meters
Now divide the distance the ball travels by the speed:
1.9 meters / 4.4 m/s = 0.43 seconds
Answer:
Explanation:
s = s₀ + v₀t + ½at²
There are an infinite number of solutions to this question as posed because we are not told the direction of the initial velocity.
Assuming ground is level and origin and UP the positive direction
The shortest amount of time possible is when the initial velocity is straight down
1.5 = 3.4 - 4.4t + ½(-9.8)t²
0 = -4.9t² - 4.4t + 1.9
t = (4.4 ±√(4.4² - 4(-4.9)(1.9))) / (2(-4.9))
positive answer is
t = 0.32 s
The longest amount of time possible is when the initial velocity is straight up.
1.5 = 3.4 + 4.4t + ½(-9.8)t²
0 = -4.9t² + 4.4t + 1.9
t = (-4.4 ±√(4.4² - 4(-4.9)(1.9))) / (2(-4.9))
positive answer
t = 1.22 s
If the initial velocity is horizontal, meaning no vertical velocity
1.5 = 3.4 + 0t + ½(-9.8)t²
-4.9t² = -1.9
t² = 0.38775...
t = 0.62 s
Any angle between UP and Down will have a different initial vertical velocity and result in a different time to catch height.
It appears from the comments on the other answer, that I have shown you how to arrive at three of the four possible solutions. The initial direction is very important.
A car was traveling at 25 m/s when it slammed on the brakes and came to a complete stop in 3 seconds. What is the cars INITIAL/FINAL VELOCITY?
Answer:
Explanation:
Initial velocity 25 m/s
final velocity 0 m/s
The ratio of the two is undefined as dividing by zero is wonky.
A skater is spinning with his arms outstretched. He has a 2 lb weight in each hand. In an attempt to change his angular velocity he lets go of both weights (by just opening his grip). Does he succeed in changing his angular velocity
Answer:
No
Explanation:
Changing momentum of any kind requires work. Work is a force acting over a distance. While holding the weights at arms length and spinning will create a force (centripetal), there is no radial distance change incurred. Releasing the weights will reduce the force to zero, still no work done and no change in angular momentum.
If he was holding the weights at arms length while spinning and he pull his hands to his chest, there now exists both the centripetal force and a distance in the direction of that force (inward radial) this work will result in an increase in angular velocity as moment of inertia has decreased with the work done.
No, the skater doesn't succeed in changing his angular velocity.
Conservation of angular momentumThe final angular velocity of the skater is determined by applying the principle of conservation of angular momentum as shown below;
Li = Lf
[tex]Ii\omega _i = I_f \omega _f[/tex]
where;
Ii is the initial moment of inertia of the skaterIf is the final moment of inertia of the skaterωi is the initial angular speed of the skaterωf is the final angular speed of the skaterWhen the skater holds the weight, the momnet of inertia of both arms is the same. Also when the skater drops the weight, the moment of inertia of both arms is still the same. Thus, at any instant, the moment of inertia of the two arms is the same.
To change the angular speed, the initial and final moment of inertia of the two arms must be different. Thus, the skater doesn't succeed in changing his angular velocity.
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. A load of 250 kg is hung by a crane’s cable. The load is pulled by a horizontal force such that the cable makes a 300 angle to the vertical plane. If the load is in the equilibrium, calculate the magnitude of the tension in the cable.
If the load is in the equilibrium, the magnitude of the tension in the cable is equal to 1,414.5 Newton.
Given the following data:
Mass of load = 250 kgAngle of inclination = 30°Scientific data:
Acceleration due to gravity = 9.8 [tex]m/s^2[/tex]To calculate the magnitude of the tension in the cable, if the load is in the equilibrium:
First of all, we would determine the tension caused by the horizontal component of the force:
[tex]\sum F_y ; Tcos\theta - mg=0\\\\Tcos\theta = mg\\\\T=\frac{mg}{cos\theta} \\\\T=\frac{250 \times 9.8}{cos30} \\\\T= \frac{2450}{0.8660}[/tex]
T = 2,829.1 Newton
The magnitude of the tension in the cable is given by:
[tex]\sum F_x ; F - Tsin\theta = 0\\\\F = Tsin\theta\\\\F = 2829.1sin30\\\\F = 2829.1 \times 0.5[/tex]
F = 1,414.5 Newton.
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a convex mirror and a plane mirror both give virtual and erect images still a convex mirror is used in vehicles. why?
Pls answer thiss
Answer:Convex mirrors are used because these mirrors provide a wider viewing angle than a plane mirror. This wide angle will help you getting more information/overview than what is happening at a narrow spot right behind the car if you use a plane mirror.
With a convex mirror you are for example able to detect an overtake (by the car behind you) early, if you for some reason wanted to turn left into another lane at the same moment the overtake took place - so you then can prevent a collision. Convex mirrors are simply covering a much larger area behind the car than plane mirrors do. And in the US, on the mirrors there is a text explaining that the vehicle behind you is closer than it appears - some kind of an idiot explanation in case some driver took the mirror image literally….because in the mirror image of a convex mirror, everything looks smaller and further away than they actually are.
Explanation: mark me as brainliest this is my best answer till now
Why Amphibians are Vanishing
Answer:Climate change, emerging diseases, and increased exposure to ultraviolet radiation (due to ozone depletion) are all additional factors that could be contributing to falling amphibian populations. ... Instead, amphibians are disappearing thanks to a complex mixture of factors, including: Alien Specie
Explanation:
just look it up........
The angle of incidence (5 points)
must equal the angle of reflection
is always less than the angle of reflection
is always greater than the angle of reflection
may be greater than, less than, or equal to the angle of reflection
Answer:
D.) the same.
They are traveling in the same vacuum so there is no resistance and no outside influences. They will travel at the same speed as each other will little to no variance in their speed.
Explanation:
hope this helps. . . <3
good luck! uωu
What conclusion can you draw from the information shown in this figure?
The speed of sound varies with the material in which the waves travel.
Sound waves can move more quickly through liquids than through solids.
Sound intensity is greater in water than in air.
The frequency of sound increases with wave speed.
Answer:
The speed of sound varies with the material in which the waves travel.
Explanation:
knowledge and research
It can be concluded as per the given table that the speed of sound varies with the material in which the waves travel. The correct option is A.
What is speed?Speed is the pace at which an object's position changes in any direction. The distance travelled in relation to the time it took to travel that distance is how speed is defined. Since speed simply has a direction and no magnitude, it is a scalar quantity.
It has a dimension of time-distance. As a result, the fundamental unit of time and the basic unit of distance are combined to form the SI unit of speed. Thus, the metre per second (m/s) is the SI unit of speed.
According to the given table, it can be inferred that the material in which the waves travel affects the speed of sound.
Thus, the correct option is A.
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PLEASE HELP!
A 2457 kg car moves with initial speed of 18 ms-?. It is stopped in 62 m by its brakes.
How much work is done by the brakes?
Answer:
Explanation:
The work of the brakes will equal the initial kinetic energy of the car
Fd = ½mv²
F = mv²/2d
F = 2457(18²) / (2(62))
F = 6,419.903...
F = 6.4 kN
what is photosynthesis
: [tex] \implies[/tex] The Photosynthesis is the process of capturing light energy and transforming it into chemical energy. Green plants and several other organisms use light energy and convert carbon dioxide and water into glucose. In this process, oxygen is produced as a by-product
→ We also who how it's process occur
In plants and blue-green algae, the photosynthesis process takes place in chloroplasts. The chloroplast is present in all green parts of a plant – the leaves, green stems, sepals, and even in the flowers, in the form of green colour plastids. The chloroplast is found only in plant cells and is essential for photosynthesis reaction.Photosynthesis Equation
Carbon dioxide and water are the two major factors involved in the photosynthesis reaction. It’s an endothermic reaction, and the products resulting from it are oxygen and glucose. The formula is:6CO2 + 6H2O = C6H12O6 + 6O2
However, some bacteria don’t produce oxygen as a by-product of photosynthesis. They are called anoxygenic photosynthetic bacteria, and those who do it are called oxygenic photosynthetic bacteria.Importance of Photosynthesis
The photosynthesis process is very important for the survival of living beings, and to continue the food chain. It also produces oxygen, which is required for breathing.Photosynthetic Pigments
Four types of photosynthetic pigments are present in the leaves of the plants. They are: Chlorophyll a chlorophyll b xanthophylls CarotenoidsThe Factors Affecting Photosynthesis
Various factors influence/affect the photosynthesis process. These are:
Light Intensity: More the light, the more will be the rate of photosynthesis. Similarly, low light will lead to a low rate of photosynthesis.The Concentration of CO2: A higher CO2 concentration rate in a plant also accelerates the photosynthesis process. The required amount of CO2 is 300-400 PPM.Temperature: If the temperature is between the range of 25 to 35 degrees Celsius, the photosynthesis takes place effectively.Water: An essential amount of water is required for stomatal opening, and it’s a key factor in the process of photosynthesis.Pollution: The increasing rate of polluting particles in the atmosphere block the pores of somatic cells, and the intake of carbon dioxide becomes difficult.▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Hope it's helps !!
How do humans obtain the carbon and energy they use in their bodies?
A. by breathing in carbon dioxide from the atmosphere
B. by consuming plants or other animals
C. by absorbing energy from sunlight
D. by absorbing carbon found in the soil
Answer:
B. . by consuming plants or other animals
For an object spinning around a central point, what will happen if its distance from the center is decreased?
A. Nothing will change.
B. Its acceleration will decrease.
C. Its acceleration will increase.
D. The centripetal force will decrease.
Answer:
Its acceleration will increase.
Explanation:
For an object spinning around a central point, Its acceleration will increase if its distance from the centre is decreased.
What is acceleration?The rate at which an item changes its velocity is known as acceleration, a vector quantity. If an object's velocity is changing, it is acceleration. The net acceleration that objects get as a result of the combined action of gravity and centrifugal force is known as the Earth's gravity
This is the acceleration of an object in a circle of radius r at a speed v. So, centripetal acceleration is greater at high speeds and in sharp curves smaller radii and for lager radii acceleration will be less.
acceleration, a = v²/r
For an object spinning around a central point, Its acceleration will increase if its distance from the centre is decreased.
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A truck moves 60 km West, and then 80 km North, and then
travels in a straight line back to its starting point. The distance
travelled by the truck is ____km and its displacement is _____km
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Distance travelled by the truck is ~
[tex] \boxed{240 \: \: km}[/tex]And it's displacement is ~
[tex] \boxed{0 \: \: km}[/tex][tex] \large \boxed{ \mathfrak{Step\:\: By\:\:Step\:\:Explanation}}[/tex]
See the diagram in attachment for reference ~
Let O be the initial point, It travels 60 km towards west till point B and then 80 km towards north till point P and returns to initial point O in a straight line, now as we can observe here, it forms a right angled Triangle.
The measure of two legs is 60 km and 80 km, let's find the hypotenuse ~
According to Pythagoras theorem ~
hypotenuse² = sum of squares of other two legs
that is ~
[tex]h {}^{2} = 60 {}^{2} + 80 {}^{2} [/tex][tex] {h}^{2} = 3600 + 640 0[/tex][tex]h {}^{2} = 10000[/tex][tex]h = \sqrt{10000} [/tex][tex]h = \sqrt{100 \times 100}{}[/tex][tex]h = 100 \: \: km[/tex]So, the distance between the point A and O is 100 km
Now, The total distance is equal to the distance covered through actual path that is ~
60 km + 80 km + 100 km 240 kmAnd displacement is the distance between the final point and initial point, but since the truck returns to the point from where it started the journey, so the final and initial point is same therefore displacement is equal to 0.
this is electricity in physics please help
Explanation:
a. (i) When the variable resistor is set at zero, the only resistance in the circuit is due to the lamp. So the current flowing through the circuit is
[tex]I = \dfrac{V}{R} = \dfrac{220\:\text{V}}{440\:Ω} = 0.5\:\text{A}[/tex]
(ii) The power output P of the lamp is given by
[tex]P = I^2R = (0.5\:\text{A})^2(440\:Ω) = 110\:\text{W}[/tex]
b. (i) The variable resistor is in a series connection to the lamp so when its value is set to its maximum value of 660 Ω, the total resistance of the circuit is simply the sum of the two resistances:
[tex]R_T = R_{vr} + R_L = 660\:Ω + 440\:Ω = 1100\:Ω[/tex]
Therefore, the current through the circuit is
[tex]I = \dfrac{V}{R_T} = \dfrac{220\:\text{V}}{1100\:Ω} = 0.20\:\text{A}[/tex]
(ii) Using the result in Part (ii), we can solve for the potential difference across the lamp as follows:
[tex]V_L = IR_L = (0.20\:\text{A})(440\:Ω) = 88\:\text{V}[/tex]
(iii) The power output of the lamp is
[tex]P = I^2R_L = (0.20\:\text{A})^2(440\:Ω) = 17.6\:\text{W}[/tex]
(iv) The rate at which electrical energy is supplied, i.e., the power output of the circuit is equal to the square of the current multiplied by the total resistance of the circuit:
[tex]P = I^2R_T = (0.20\:\text{A})^2(1100\:Ω) = 44\:\text{W}[/tex]
A ball is thrown vertically down from the edge of a cliff with a speed of 4 m/s, how high is the cliff, if it took 12 s for the ball to reach the ground?
I need the Formula
Hi there!
We can use the equation:
d = v₀t + 1/2at²
Where:
v₀ = initial velocity downward
a = acceleration due to gravity
t = time
Plug in given values:
d = 4(12) + 1/2(9.8)(12²)
d = 48 + 705.6 = 753.6 m
A 0.50-kg mass is attached to a spring of spring constant 20 N/m along a horizontal, frictionless surface. The object oscillates in simple harmonic motion and has a speed of 1.5 m/s at the equilibrium position. What is the total energy of the system?
Hi there!
With the work-energy theorem for oscillating springs:
ME = KE + PE
[tex]ME = \frac{1}{2}mv^2 + \frac{1}{2}kx^2[/tex]
Where:
m = mass (kg)
v = velocity (m/s)
k = Spring Constant (N/m)
x = displacement from equilibrium (m)
If the object is at the equilibrium position, there is NO potential energy since:
[tex]\frac{1}{2}k(0^2) = 0 J[/tex]
Thus:
[tex]ME = \frac{1}{2}mv^2[/tex]
Plug in the given values:
[tex]ME = \frac{1}{2}(0.50)(1.5^2) = \boxed{0.5625 \text{ J}}[/tex]
Find the dimension of the gravitational constant in this equation F=Gm1m2/r¹r²
The gravitational force acting between the two bodies is given by:
F=G
r
2
m
1
m
2
G=
m
1
m
2
Fr
2
The dimension of the force is [MLT
−2
]
=
[M][M]
[MLT
−2
][L
2
]
=M
−1
L
3
T
−2
Carbon tetrachloride (CCl4) is diffusing through benzene (C6H6), as the drawing illustrates. The concentration of CCl4 at the left end of the tube is maintained at 1.71 x 10-2 kg/m3, and the diffusion constant is 21.9 x 10-10 m2/s. The CCl4 enters the tube at a mass rate of 5.86 x 10-13 kg/s. Using these data and those shown in the drawing, find (a) the mass of CCl4 per second that passes point A and (b) the concentration of CCl4 at point A.
We have that for the Question "find (a) the mass of CCl4 per second that passes point A and (b) the concentration of CCl4 at point A."
Answers:
Mass of CCI_4 per second = [tex]5.86*10^{-13} kg/s[/tex] Concentration of CCI_4 = [tex]12.6*10^{-3}kg/m^3[/tex]
From the question we are told
The concentration of [tex]CCl_4[/tex] at the left end of the tube is maintained at 1.71 x 10-2 kg/m3, and the diffusion constant is 21.9 x 10-10 m2/s. The CCl4 enters the tube at a mass rate of 5.86 x 10-13 kg/s
A) the mass flow rate of CCI_4 as it passes point A is the same as the mass flow rate at which CCI_4 enters the left end of the tube
Therefore, the mass flow rate of CCI_4 at point A
= [tex]5.86*10^{-13} kg/s[/tex]
B) From Fick's law
[tex]\deltaC = \frac{mL}{DAt}\\\\ Assume L = 5*10^{-3}, A = 3*10^{-4}\\\\\deltaC = \frac{5.86*10^{-13} * 5*10^{-3}}{21.9*10^{-10} * 3*10^{-4}}\\\\\deltaC = 4.46*10^{-3}kg/m^3[/tex]
Then,
[tex]Concentration = 1.71*10^{-2} - 4.46*10^{-3}\\\\= 12.6*10^{-3}kg/m^3[/tex]
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plz answer the question.
Answer:
A. Determine the equation of constraints
6. How are the temperature of the universe and Cosmic Microwave Background (CMB) related?
A. Astronomers use the temperature of CMB as the warmest temperature in the universe
B. Astronomers calculate the temperature of the universe based on the coldest part of the CMB
C. Astronomers consider the temperature of the universe to be the temperature of CMB
D. Astronomers never consider the temperature of CMB when looking at the temperature of the universe
Answer:
I think the answer is (A)...
Hope this helps!
F=mass x what does this equal?
Answer:
Force = mass × acceleration.
I need the answer fast for c pleaseeee
Answer:
F = - K x for spring (note that that F here is given in grams, F = m g is correct)
K here is 100 g / cm for the spring constant
x = -420 g / 100 g/cm = -4.2 cm
The spring would compress 4.2 cm for a total length of 20 - 4.2 = 15.8
d) to compress the spring 6.8 cm one can see that the load would be 680 g
Water has higher specific heat than aluminum. This is all what you should know to answer following questions. An aluminum rod of mass 1 kg at temperature of 80^0C is placed into 1l of water of temperature 10^0C . there is no heat exchange with surroundings. Which material experiences greater change in temperature while system is reaching the thermal equilibrium
Answer:
The Aluminum
Explanation:
With a larger specific heat, water requires more heat to raise its temperature by a temperature degree.
In this system, with equal masses of water and aluminum, the heat moving from the aluminum lowering its temperature by one degree is not sufficient to raise the water temperature by one degree.
A train slows its speed from 52 kilometers per hour to 46 kilometers per hour in 0.04 hour. What is the acceleration o the train during this time?
Answer: here you go i have to put 20 letters in so just ignore this and look at the link.
If m1 is 24 kilograms, m2 is 12 kilograms, and mbar is 10 kilograms, what is the direction of rotation and the sign of the angular acceleration
From the diagram, the angular speed will increase clockwise, the sign of the angular acceleration will be negative and the direction of rotation will be clockwise direction and the sign of the angular acceleration is negative. The correct answer is option B
Given that two objects of masses m1 and m2 are attached to a seesaw. The seesaw is made of a bar that has length l and is pivoted so that it is free to rotate in the vertical plane without friction. Counterclockwise is considered the positive rotational direction.
If m1 is 24 kilograms, m2 is 12 kilograms, and mbar is 10 kilograms, The moment of object m1 will be equal to the moment of object m2 without the Mbar
Let assume that the length L of the seesaw is 9 cm.
Anticlockwise moment = 24 x 9/3 = 72Nm
Clockwise moment = 12 x 2(9/3) = 72 Nm
With the consideration of mass of the bar Mbar, this will add to clockwise moment of the seesaw.
Therefore, the direction of rotation will be clockwise direction.
Angular acceleration is positive when object is speeding up and negative when slowing down. Also, angular acceleration is positive when speed increases in an anticlockwise direction and negative when speed increases in the clockwise direction.
From the diagram, since the angular speed increase clockwise, the sign of the angular acceleration will be negative.
We can conclude that the direction of rotation will be clockwise direction and the sign of the angular acceleration is negative.
The correct answer is option B
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The thermometer bulb should have____
a) high heat capacity
b) No heat capacity
c) Small heat capacity
d) Varying heat capacity
Explain why a tiny 1.5 V cell can operate a calculator for a year, while a much larger 1.5 V cell burns out in a few hours in a tiny robot. I WILL CHOOSE BRAINIEST!! PLEASE HELP
The reason why a tiny 1.5 V cell can operate a calculator for a year, but would burn out in a few hours in a tiny robot is because the power demands of the calculator are way less than that of the tiny robot.
What controls how long a cell lasts ?Cell capacity is measured by the amount of Amps and Amp Hour (A.H.) capacity for how long a battery can endure.
On the label or in the user's manual, batteries mention their reserve capability, which specifies the approximate amount of time they can operate between charges. You might notice a shorter or longer battery life if your circuit uses more or less power than this hypothetical circuit. Calculate the battery's entire capacity and divide it by the power of your circuit to see how long it can survive.
Load current, which is influenced by the power of the linked item, influences how quickly the battery's electrical capacity will be used up.
The reason the 1.5 V cell would operate the calculator for a year and yet die in a few hours with the robot is that the robot has a much higher load current than the calculator.
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What is discordant characteristic ?
[tex] \: \: \: \: [/tex]
being at variance; disagreeingor incongruous: discordant opinions. disagreeable to the ear; dissonant; harsh.hope it helps[tex] \: \: \: \: \: [/tex]
dissimilar with respect to one or more particular characters
A small 1240-kg SUV has a wheelbase of 3.2 m. If 67% of its weight rests on the front wheels, how far behind the front wheels is the wagon's center of mass
Answer:
Explanation:
Let d be the distance to the center of mass from the front wheels
Sum moments about the front wheel contact point to zero
1240(9.8)[d] - 1240(9.8)(1 - 0.67)[3.2] = 0
1240(9.8)[d] = 1240(9.8)(1 - 0.67)[3.2]
d = (1 - 0.67)[3.2]
d = 1.056 m