Answer:
Usual speed: [tex]500\; {\rm km \cdot h^{-1}}[/tex].
Explanation:
Let the usual duration of the trip be [tex]t[/tex] hours ([tex]t > 0[/tex].) The actual duration of this trip would be [tex](t - (1/2))[/tex] hours.
The usual speed would be:
[tex]\begin{aligned}\frac{1500}{t}\end{aligned}[/tex].
The actual speed would be:
[tex]\begin{aligned}\frac{1500}{t - (1/2)}\end{aligned}[/tex].
The actual speed is [tex]100\; {\rm km \cdot h^{-1}}[/tex] greater than the usual speed. In other words:
[tex]\begin{aligned}\frac{1500}{t - (1/2)} - \frac{1500}{t} = 100\end{aligned}[/tex].
Simplify this equation and solve for [tex]t[/tex] ([tex]t > 0[/tex]):
[tex]\begin{aligned}\frac{15}{t - (1/2)} - \frac{15}{t} = 1\end{aligned}[/tex].
[tex]\begin{aligned}15\, t - 15\, \left(t - \frac{1}{2}\right) = t^{2} - \frac{1}{2}\, t\end{aligned}[/tex].
[tex]\begin{aligned}t^{2} - \frac{1}{2}\, t - \frac{15}{2} = 0\end{aligned}[/tex].
[tex]2\, t^{2} - t - 15 = 0[/tex].
[tex](2\, t + 5)\, (t - 3) = 0[/tex].
Since [tex]t > 0[/tex], the only possible value for [tex]t[/tex] would be [tex]t = 3[/tex].
Thus, the usual duration of this trip would be [tex]3\; {\rm h}[/tex]. The usual speed of this trip would be:
[tex]\begin{aligned}v &= \frac{s}{t} = \frac{1500\; {\rm km}}{3\; {\rm h}} = 500\; {\rm km \cdot h^{-1}}\end{aligned}[/tex].
What is the ratio between the initial and final kinetic energies of a car, if its velocity is increased by four times?
1:8
1:7
1:16
Let initial velocity be v
So
initial kinetic energy
KE=1/2mv²Final velocity is four times v i.e 4v
Final kinetic energy
KE=1/2m(4v)²KE=1/2m(16v²)Find ratio
1/2m(16v²):1/2mv²16v²:v²16:1Or
1:16Option C
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Which nucleus completes the following equation?
212 86 Rn-> 4 2 He+?
Answer:
A
Explanation:
208+4=212
84+2=86
The correct answer is A
a 55kg skater is speeding towards a ramp. if the skater reaches a height of 0.8m before coming to a stop, how fast was the skater going in the beginning? ignore any friction.
Answer:
3.96 meters / sec
Explanation:
The skaters Kinetic Energy is converted to Potential Energy ( ignoring friction)
KE = PE
1/2 * 55 * v^2 = 55 * 9.81 * .8
solve for v = 3.96 m/s
A weight lifter does 586 J of work on a weight that he lifts in 3.5 seconds. What is the power with which he lifts the weight?
need help fast please
Answer:
Explanation:
The quantity of energy transferred by a force when it is applied to a body and causes that body to move in the direction of the force work.
12. What are the components of the vector with a magnitude of 65.0 and a direction of 101.7°?
O (13.2, -63.6)
O (63.6, -13.2)
O (-63.6, 13.2)
O (-13.2, 63.6)
Answer:
V = 65 at 101.7 deg
Vx = V cos θ = 65 cos 101.7 = -13.2
Vy = V sin θ = 65 sin 101.7 = 63.6
The last option is correct
PLEASE HELP:
Calculate the net force on the box shown in the picture:
Determine the DIRECTION that this box will move once the force is exerted on it.
Determine whether this is a balanced or unbalanced force and what direction the box moves.
ill give u brainliest :)
Answer:
17N
Explanation:
the side with most net force is going to be deducted by the side with the least net force.
When boarding an airplane you bring a bag of chips. While in flight the bag puffs up, because suction is occurring. air pressure is affected by the Bernoulli principle. air pressure in the air-tight bag is greater than cabin air pressure. all the above none of the above
Answer:
air pressure in the air-tight bag is greater than cabin air pressure
Explanation:
When friction occurs, which of the following types of energy is produced?
оооо
chemical energy
electromagnetic energy
heat energy
nuclear energy
Answer:
heat energy
Explanation:
Friction causes the molecules on rubbing surfaces to move faster, so they have more energy. This gives them a higher temperature, and they feel warmer.
How does the force of gravity
affect objects on Earth?
A. It pulls objects towards the center of Earth.
B. It pushes objects to Earth's surface.
C. It pushes objects away from Earth.
D. It causes objects to bounce off each other.
Answer:
A. It pulls objects towards the center of Earth.
Explanation:
Think about dropping something, where does it go? If you are on earth, this goes down towards the ground due to the attractive force of gravity on every object (to pull everything to center of earth). Like Newton's apple.
1 astronomical unit (A) is
149,597,871 kilometres
hope it helps...!!!
Please help me with those multiple choice
Answer:
11. Light waves are electromagnetic (created by electromagnetic impulse)
12. Light waves in a medium are slower V = C / Nm where Nm is the index of refraction of the medium
13. The frequency of the vibration remains the same
14. The wavelength of light in the medium is less
λ = V / f and it was determined in 12 that the velocity is less in the medium
What is the wavelength a wave if it has a frequency of 7,143 Hz and a velocity of 1,151 m/s?
Wavelength = 0.16m to 2.dp
Wavelength = wave speed / frequency
= 1,151 ÷ 7,143
= 0.1611367773
Hope this helps!
Ball 1, with a mass of 100 g and traveling at 10 m/s, collides head-on with ball 2, which has a mass of 300 g and is initially at rest. What are the final velocities of each ball if the collision is (a) perfectly elastic
Look at the diagram below. What will the reading on voltmeter 1 be?
Enter your answer as a number
1.5v 1.5v
HE
(A2
A3
10 Ω
V2
V
10 Ω
V1
A1 0.15A
Answer:
1.5v
Explanation:
This is a series circuit with identical components, so the potential difference will be shared equally between each component. (1.5V + 1.5V) / 2 = 1.5V
According to the diagram, voltmeter 1 will show 1.5 V. Because it is a series combination voltmeter 2 will also show 1.5 V.
What is a Voltmeter?The potential difference, or voltage, between two points in an electrical or electronic circuit is measured using a voltmeter, also referred to as a voltage meter. While some voltmeters are made for use in alternating current (AC) circuits, others are meant to be used in direct current (DC) courses. Voltage for radio frequency (RF) can be measured using specialized voltmeters.
A simple analog voltmeter is a high resistance connected in series with a sensitive galvanometer (current meter). A voltmeter needs to have high internal resistance. Otherwise, it will consume a sizable amount of current, interfering with the test circuit's performance. The range of voltages that the meter can display depends on the series resistance value and the sensitivity of the galvanometer.
Since all of the components in this series circuit are the same, any potential difference will be distributed equally i.e., (1.5V + 1.5V) / 2 = 1.5V
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When an ice pack is applied to an injury, thermal energy from the injured area transfers to the ice, causing the blood
vessels within the area to constrict, which reduces the swelling.
How is thermal energy transferred in this scenario?
a conduction
b convection
c radiation
Thermal energy from the injured area transfers to the ice and the thermal energy transferred in this scenario is conduction.
What is Heat transfer by conduction?
Conduction heat transfer is the transfer of heat through matter such as solids, liquids, or gases without bulk motion of the matter.
The ice pack absorbs the heat energy without the actual movement of the molecules of the ice pack.
Thus, thermal energy from the injured area transfers to the ice and the thermal energy transferred in this scenario is conduction.
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Answer:
1. What is the best description of thermal energy?
B) Thermal energy is the energy in matter due to the movement of its atoms and/or molecules.
2. An athlete hurts their wrist. They put an ice directly on the wrist. In which direction is the thermal energy moving?
B) The thermal energy is moving from the wrist to the ice pack.
3. What happens when two substances with different temperatures come into contact?
B) Thermal energy is transferred from the warmer substance to the cooler substance.
4. Which is the best description of what happens when thermal energy is removed from a substance?
B) Its particles lose kinetic energy and move more slowly.
5. Which of the following is typically part of the knowledge base of research and development scientists working on heating devices?
A) substances and their properties
Explanation:
i just finished the quick check
what is a ravine and why are they made
A ravine is a smaller version of a canyon that is typically formed by stream bank erosion. Ravines are greater in scale than gullies, but smaller than valleys.
What is ravine?A ravine is a slope landform with relatively steep sides,Ravines may or may not contain active streams running along the down slope channel that produced them.
Ravine are frequently characterized by intermittent streams, since their geographic size is too small to maintain a perennial watercourse.
Hence, a ravine is a smaller version of a canyon that is typically formed by stream bank erosion.
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PLEASE HELP ME!
For each equation, state the reaction type and then balance the equation.
___Na3PO4 + ___HCl → _ __H3PO4 + ___NaCl
___KClO3 → __O_KCl + ___O2
#1
Double displacement reaction
Balanced one
Na_3PO_4+3HCl—»H_3PO_4+3NaCl#2
Decomposition reaction
Balanced one
2KClO_3—»2KCl+3O_2Find the wavelength of a sound moving in air at 43.2 m/s and that has a frequency of
2.11 hz.
a. 20.47
b. 91.152
c. 0.0488
d. 177.35
please help!!
Answer:
a.) 20.47 mExplanation:
Here we are given sound moving in air at 43.2 m/s and that has a frequency of 2.11 hz and we need o calculate the Wavelength.
Using formula:
[tex] \\ \: \: \longrightarrow \: \: \:{ \underline{ \boxed{ \sf Frequency = \dfrac{Wave \: speed}{Wave \: length}}}} \\ [/tex]
Where,
Frequency = 2.11 HzWave speed = 43.2 m/sOn Substituting the values, we get:
[tex]\\ \sf \: \: \: \longrightarrow \: \: \: 2.11 = \dfrac{43.2}{Wave \: Length} \\ \\ \\ \sf \: \: \: \longrightarrow \: \: \:Wave\: Length = \frac{43.2}{2.11} \\ \\ \\ \sf \: \: \: \longrightarrow \: \: \:{ \pink{ \underline{Wave \:Length = 20.47 m}} }\\ \\ [/tex]
Hence,
Wavelength of a sound moving in air is 20.47 m[tex]\large\boxed{\bold{Formula: λ= \frac{v}{f}}}[/tex]
In this question all the values are given so we'll simply have to substitute the values and solve.
Let's solve!
We'll have to divide the velocity or speed by the frequency.
Substitute the values according to the formula.
[tex] λ= \frac{43.2}{2.11}[/tex]
Calculator answer:
[tex]\bold{λ= 20.47393365 \: m}[/tex]
Now, we can round off to the nearest hundredth.
The value in the thousandths place is smaller than 5 so we won't have to round up.
Final answer:
[tex]\large\boxed{\bold{λ= 20.47 \:m}}[/tex]
Therefore, the wavelength is 20.47 meter.
Answer: Option A
define scientific measurement
Answer:
Measurements are a basic necessity in science. Scientists have designed thousands of different tools to help in the vital process of measuring. In this image of the control panel of the space shuttle Atlantis, we see dozens of readouts from measuring systems.
PLEASE HELP ME!!!
predict the products of each of the following equations. Then explain how you made your predictions. Be sure to balance the equations.
___NaBr + ___Ca → _______ + _______
___Mg + ___O2 → _______
#1
Here
Calcium is less reactive than sodium so it can't displace Na .
Nothing will happen
#2
Mg+O_2—»MgOThis is oxidation
hellooooooooooo peopleeeee
If the half-life of iodine-131 is 8.10 days, how long will it take a 50.00 g sample to decay to 6.25 g?
The time it will take to decay 6.25 grams is 24.4684 days.
What is Half life period?A radioactive substance's half-life is often described as the amount of time it takes for one of its atoms to break apart or transform into another. Ernest Rutherford originally examined the theory in 1907. This is typically represented by the sign Ug or t1/2.
To make the concept clearer, let's use a radioactive element with an hour-long half-life.
Now according to the question the given values are :
T(1/2) for iodine-131 is 5.10 days,
[A]₀ for iodine-131 is 50 grams and,
[A] for iodine-131 is 6.25 grams.
T(1/2)=0.693/k
⇒8.10=0.693/k
⇒k=0.865 [tex]days^{-1}[/tex].
2.303 log [A]₀/[A]= kt
2.303 log(50.00/6.25)= 0.085×t
⇒t=1/0.085×2.303×log8
t=24.4684 days
Hence, the time it will take to decay is 24.4684 days.
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name any two instruments based on archimede's principle
Two instruments based on Archimedes' principle
LactometershydrometersExplanation:
Archimedes' principle states -
when a body is partially or completely immersed in a fluid , the fluid exerts an upward force on the body which is equal to the weight of the fluid displaced by the body.OR
when a body is immersed fully of partially in a fluid , it experiences an upward force that is equal to the weight of the fluid displaced by it.Applicatios : Lactometer , hydrometer.
True or false: when two objects are rubbed together they both will have either a positive charge or both be negatively charged. Causing them to then repel each other. (1 Point) True False not enough information Maybe
Answer:
true
Explanation:
because rubbing together they will both have friction
Hip hop dance translate feelings and emotions of human conditions, situations, or fantasies into movement and dramatic expressions? True or false?
Answer:
false .....................
Can someone please answer this, ill give you brainliest Would be very appreciated.
The order is followed as
photosynthesisDecompositionCombustionRespirationDiffusionAnswer:
See below ~
Explanation:
Done from left to right :
Box 1 : Photosynthesis
Box 2 : Respiration
Box 3 : Combustion
Box 4 : Decomposition
Box 5 : Diffusion
Ben created the table below to identify the roles of
different parts of the eye.
Part
Role
Cones
provide color visions through three
types of cells
Lens
focuses light to form an
upside-down, virtual image
Iris
adjusts the size of the pupil to
control the amount of light
receives image of the object and
contains cells that detect light
Retina
Which describes Ben's error?
There is a single type of cone cell.
The lens forms a real image.
The iris is a hole through which light passes.
The retina carries the signals to the brain.
Answer:
the answer is The lens forms a real image.
Explanation:
got it right on edge
The following diagram shows two meteors with masses of 1,000 kilograms and 3,000 kilograms spaced 10 meters apart. What is the magnitude of the gravitational force exerted by the 1,000 kg meteor on the 3,000 kg meteor? 2 × 10-9 N, 2 × 10-6 N, 7 × 10-10 N, 2 × 10-2 N
The attraction between masses as small as our bodies, or even objects the size of skyscrapers, is incredibly small. For example, two 1.0-kg masses located 1.0 meter apart exert a force of 6.7×10−11N 6.7 × 10 − 11 N on each other.Answer:
Explanation:
Even between objects the size of skyscrapers or masses as small as our bodies, there is incredibly little attraction. For instance, a force of 6.71011N is generated when two 1.0-kg masses are placed 1.0 meters apart. 6.7 10 11 N on top of one another.
What magnitude of gravitational force by the meteor?M/s2 is its SI unit. Its vector nature—which includes both magnitude and direction—makes it a quantity. The unit g stands for gravitational acceleration. At sea level, the standard value of g on earth's surface is 9.8 m/s2.
The magnitude of PQ is represented symbolically as | PQ |. The Distance Formula can be used to determine a vector's magnitude if its start and end points' coordinates are known.
Therefore, The distance between a vector's starting point P and ending point Q is its magnitude.
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Why is it important to assess flexibility both before and during a workout regimen? a. to assess flexibility progress b. to keep muscles warm c. to establish flexibility baselines d. none of the above please select the best answer from the choices provided. a b c d
It important to assess flexibility both before and during a workout regimen because to assess flexibility progress.
What is a flexibility exercise?Flexibility exercises, as the name implies, help to increase the stretch of the muscles, improving the range of motion. More flexibility is also important to help prevent possible post-workout soreness.
In this case we have that the reason to continue doing stretching before and during the exercises is about to assess flexibility progress.
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Answer:
A
Explanation:
Good evening! Can someone please answer this, ill give you brainliest and your earning 50 points. Would be very appreciated.
Answer:
Drinking water
Direct as we are achieving water directly by ourselvesOur foods
Indirect as foods contain water we are getting water indirectly from themWashing clothes
Direct as direct contact of water is here