Answer:
friction. or gravity both ofbthem .....................
..
Which are examples of perfectly inelastic collisions? Check all that apply.
a baseball bouncing off a bat
bumper cars bumping off of each other
a cue ball hitting an eight ball and stopping
a plane landing on an aircraft carrier
rain sticking to a window
two train cars coupling together
Answer:
D. a plane landing on an aircraft carrier
E. rain sticking to a window
F. two train cars coupling together
Explanation:
45. 3. (III) A 7.26 kg bowling ball hangs from the end of a 2.5 m rope. The ball is pulled back until the rope makes an angle of 45 with the vertical. a. What is the increase in the ball’s potential energy when it is lifted? b. If the ball is released from rest and swings downward like a pendulum, how much kinetic energy will the ball have at the bottom of its swing? c. How fast will the ball be moving at the bottom of its swing?
Explanation:
For the first question look at the picture. It should be pretty clear. Remember that cos45° = sqrt2 / 2.
2) We calculate it thanks to the conservation of mechanical energy:
Em1 = Em2
U1 + K1 = U2 + K2
K1 = 0J
U2 = 0j
U1 = K2
3) mgh = 1/2mv^2
v = sqrt(2gh)
What is the half-life of an isotope if after 30 days you have 31.25 g remaining from a 250 g beginning sample size?
The half-life of the given isotope will be 10 days, if after 30 days only 31.25 grams are remaining from a sample of 250 grams of the sample size taken in the beginning.
What is Half-life of an element?
The Half-life is the time which is required for a quantity to reduce the content to half of the amount present as its initial value. The term is used in nuclear physics to describe how quickly an unstable atom undergo radioactive decay or how long does stable atoms survive. The term is also used generally to characterize any type of exponential decay.
The half-life of the isotope can be calculated by the formula:
FR = 0.5n
FR = Fraction Remaining = 31.25 g / 250.0 g = 0.1250
n = number of half lives elapsed = ?
0.125 = 0.5n
log 0.125 = n log 0.5
-0.9031 = -0.3010 n
n = 3.000 half lives have elapsed
3 half lives = 30 days
1 half live = 10 days
Therefore, the half-life of the isotope will be 10 days.
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why is water soaked cloth used on forehead during fever?please can you tell me answer
This is because the cloth soaked in water can absorb and evaporate the heat from your forehead.
Explanation:This technique is used to cool down your fever, and to help you feel better.
Learning Task 1: Define or describe the following words relat are not familiar with the word, you may ask assistance from y your answer in your notebook. 1. table 2. tennis C 3. ping-pong 4. net 5. ball 6. racket
Answer:
1.) TABLE = The table is 2.74 m (9.0 ft) long, 1.525 m (5.0 ft) wide, and 76 cm (2.5 ft) high with any continuous material so long as the table yields a uniform bounce of about 23 cm (9.1 in) when a standard ball is dropped onto it from a height of 30 cm (11.8 in), or about 77%.
2.) TENNIS = Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court.
3.) PING-PONG = Table tennis, also known as ping-pong and whiff-whaff, is a sport in which two or four players hit a lightweight ball, also known as the ping-pong ball, back and forth across a table using small rackets. ... Spinning the ball alters its trajectory and limits an opponent's options, giving the hitter a great advantage.
4.) NET = This is stretched across the centter of the table by a cord attached to a post at either end. It measures 6ft long and the ball must pass over it for a rally to continue.
5.) BALL = The ball, which is spherical and hollow, was once made of white celluloid. Since 1969 a plastic similar to celluloid has been used. The ball, which may be coloured white, yellow, or orange, weighs about 0.09 ounce (2.7 grams) and has a diameter of about 1.6 inches (4 cm).
6.) RACKET = A table tennis racket is made up of two distinct parts - a wooden blade which incorporates the handle together with table tennis rubbers affixed to each side of the blade using water-based glue.
Explanation:
All my answers are
about the tools of the
game of tennis
how does gravitational lensing tell us about the mass of a galaxy cluster?
Answer:
Newton's universal law of gravitation predicts how mass can distort light, so we can apply Newton's law to determine the mass of the cluster. ... The lensing allows us to determine the orbital speeds of galaxies in the cluster, so that we can determine the mass of the cluster from the orbital velocity law.
Explanation:
Define "one solar day".
Answer:
the interval between transits of the apparent or mean sun across the meridian at any place.
A 7.5 kg beaver dives horizontally off a 50 kg log at a speed of 4 m/s. What is the speed of the log?
Answer:
[tex]0.6\; \rm m\cdot s^{-1}[/tex], assuming that drag of the water on the log is negligible.
Explanation:
The momentum [tex]p[/tex] of an object is equal to the product of mass [tex]m[/tex] and velocity [tex]v[/tex]. That is, [tex]p = m\, v[/tex].
If the drag of water on the log is negligible, momentum of the beaver and the log, combined, would be preserved.
The momentum of the beaver and the log, combined, was initially [tex]0\; \rm kg\cdot m \cdot s^{-1}[/tex].
The momentum of the beaver right after the dive would be [tex]7.5 \; {\rm kg} \times 4\; {\rm m \cdot s^{-1}} = 30\; {\rm kg \cdot m \cdot s^{-1}}[/tex].
The sum of the momentum of the beaver and the log is conserved and should continue to be [tex]0\; {\rm kg\cdot m \cdot s^{-1}}[/tex] even after the dive. Since the momentum of the beaver is [tex]30\; {\rm kg \cdot m \cdot s^{-1}[/tex] after the dive, the momentum of the log should become [tex](-30)\; {\rm kg \cdot m \cdot s^{-1}}[/tex].
Since the mass of the log is [tex]50\; {\rm kg}[/tex], the new velocity of this log would be:
[tex]\begin{aligned}v &= \frac{p}{m} \\ &= \frac{(-30)\; {\rm kg \cdot m \cdot s^{-1}}}{50\; {\rm kg}} \\ &= (-0.6)\; {\rm m \cdot s^{-1}}\end{aligned}[/tex].
(The new velocity of the log is negative because the log would be moving away from the beaver.)
The speed of an object is the magnitude of velocity. For this log, a velocity of [tex](-0.6)\; {\rm m \cdot s^{-1}}[/tex] would correspond to a speed of [tex]|(-0.6)\; {\rm m \cdot s^{-1}| = 0.6\; {\rm m \cdot s^{-1}[/tex].
You are pulling a friend on a sled with a constant velocity using a rope held
horizontally in the snow. Using a spring scale attached to the rope, you
measure the tension to be 112 N. The combined mass of the sled and your
friend is 57.4 kg. Write the surface force the ground exerts on the sled in
component form, and determine its magnitude.
Here are all the steps.
When you are pulling a sled with constant velocity with a rope then the ground exerts a surface force on the sled will be equal to 573.56 N.
What is tension?The pulling force delivered axially by a cable, string, chain, or by either end of a rod, truss member, or another such 3-D object is known as tension in physics. Tension can be described as the action-reaction pair of forces acting at each end while tension is a polar opposite of compression.
A restoring force causes tension when atoms or molecules are torn apart at the atomic level and build up potential energy.
When you are trying to move upward and push in a positive way,
F = - 112 i + 57.4 (9.8) j
F = -112 i + 562.52 j
[tex]F = \sqrt{(-112)^2+ (562.52)^2}[/tex]
[tex]F =\sqrt{12544 + 316428.7}[/tex]
F = 573.56 N
Therefore, the surface force the ground exerts on the sled is 572.52 N.
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Help plz I don’t know it
Answer:
2. thermal insulator. 3. convection current. 4. conduction. 5. thermal conductor. 6. radiation.
Explanation:hope this helps you.
what are the main component of network
Answer:
A network has 5 basic components viz. clients, servers, channels, interface devices and operating systems.
7. a heater heating up the inside of the car
Convection conduction and radiation
why is creavity important inn constructing scientific methods
1) A creative method can save money when you have limited resources
2) A scientific experiment is always very boring
3) There is only one experiment that can test each hypothesis
4) There is no creativity in the scientific community.
Answer:
The answer is C
Explanation:
Scientists use creativity to determine which smaller questions are likely to yield results, imagine possible answers to their questions, and devise ways to test those answers.
Creativity is the key to make the scientific experiments more efficient and and economic and hence, a creative method can save money when you have limited resources.
What is a scientific method?A scientific method is constituted by a set of stages and instructions to conduct a scientific experiment to attain a possible solution for a problem. Scientific methods have to be reproducible and effective to bring a valid solution for a hypothesis based on an observation.
Creative thinking is always paramount significance because it leads more ways and identifies the pitfalls in the available scientific methods. Creativity improves the way of designing a scientific experiments and to gather informations also.
Therefore, creative method can save money when you have limited resources is a true statement regarding a scientific method.
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You want to replace the resistor in your
boiler with a more efficient one during win-
tertime. Would you replace it with another
one double the length or half the length?
To make the boiler more efficient, we would replace the resistor with another double the length.
We know that the resistance of the resistor in the boiler is given by R = ρl/A where
ρ = resistivity, l = length of resistor and,A = cross-sectional area of resistor.Also, the power generated by the resistor is P = i²R where
i = current and R = resistance.If i is constant, we see that P ∝ R.
So, to increase the efficiency, the value of the resistance has to increase.
Also, since R = ρl/A and ρ and A are constant, we see that R ∝ l.
Since P ∝ R and R ∝ l ⇒ P ∝ l.
So, to increase the efficiency, we would double the length of the resistor.
So, to make the boiler more efficient, we would replace the resistor with another double the length.
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does a perfectly elastic colission conserve momentum and impulse
Answer:
A perfectly elastic collision conserves momentum and kinetic energy..
In the United States, radioactive waste is divided into three main categories based on their activity, their heat generation potential, and what they physically contain.
Low level radioactive waste is the least dangerous type of nuclear waste. It contains relatively small amounts of radioactive substances with short half-lives.
Which of the following methods is most commonly used to dispose of low level radioactive wastes?
A.
activating reactions so the material is no longer radioactive
B.
sealing the waste into steel tanks and burying the tanks deep into the ground
C.
compacting the waste and burying it in a shallow landfill
D.
sealing in a biohazard bag and disposing the bag with ordinary trash
Answer:
C.Compacting the waste and burying it in a shallow landfill.
Explanation:
It is buried in a shallow landfill because it is less reactive.
The length of daylight changes as the seasons change during the year. what causes these changes in the number of daylight hours?
Answer:
The earth travels around the sun in a (parabolic) path known as the ecliptic.
The axis of the earth's rotation is tilted about 23 deg to the ecliptic.
At the winter solstice (around Dec. 21), the sun will appear to be at its farthest south in its orbit. (This marks the beginning of winter for observers in the northern hemisphere and the beginning of summer for an observer in the southern hemisphere)
The tilt of the axis of the earth's rotation causes the change in the daylight hours.
a car dealer sells 4 makes of cars in 5 colors with either standard or automatic transmissions. how many variations does the dealership offer?
The number of variations the dealership have is 40 cars.
Data given;
The number of different product = 4The number of transmission = 2 (standard or automatic)The numbers of colors available = 5Dealership variationThis is the total numbers of cars available in the dealer shop at the moment.
To get that, we simply multiply the numbers of colors available, the number of transmission and the makes of car available.
This is equal to
[tex]4*2*5=40[/tex]
From the above calculation, we can say that the variations the dealership offers is 40
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how to calculate kinetic energy given mass and velocity
In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.
You are pulling a child in a wagon. The rope handle is inclined upward at a 60∘ angle. The tension in the handle is 20 N.
Part A
How much work does the rope do on the wagon if you pull the wagon 200 m at a constant speed?
Answer:
2000 J
Hope you could get an idea from here.
Doubt clarification - use comment section.
S O L U T I O N:
Here we've been provided with the information i.e
Force (F) = 20N Distance (s) = 200m Angle (θ) = 60°Ans we have given to find out what is work done (W) = ?
The standard formula to calculate work done is given by,
[tex]:\implies\sf{w = f \times s \times cos \theta}[/tex]
[tex]:\implies\sf{w = 20 \times 200 \times cos60}[/tex]
[tex]:\implies\sf{w = 20 \times 200 \times \frac{1}{2} }[/tex]
[tex]:\implies\sf{w = 20 \times 100 \times 1}[/tex]
[tex]:\implies\sf{w = 2000J}[/tex]
Total work done done by rope is 2000J.A bus accelerates away from the bus stop at 2.5 m/s2
.
The total mass of the bus and passengers is 14 000 kg.
Calculate the resultant force needed to accelerate the bus and passengers.
help pls my brain is not working
Explanation:
F=k.g m\s2
=2.5 m\s2 14000k.g
= 35000N
A wave completes one vibration as it moves a distance of 2 meters at a speed of 20 meters per second. What is the frequency of the wave?
I need the Formula,Known,Substitute & Solve Answer with Units
Answer:
I put the answer
Explanation:
Can you see it
10Hz is the frequency of the wave.
How to find the frequency of the wave?
To calculate the frequency of a wave, divide the velocity of the wave by the wavelength. Write your answer in Hertz or Hz
Given,
F = 2
λ=2m
v=20m/s
By applying the formula, we get
V = Fλ
F = V / λ
F = 20 / 2
=10Hz
Wave frequency is the number of waves that pass a fixed point in a given amount of time.
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what is the necessary condition for the conservation of angular momentum
Answer:
The conservation of momentum of a system is a fundamental principle in classical mechanics. The only condition for this principle being valid is that the system should be an isolated one, i.e. It should not be acted upon by any external force.
When Magnesium and Fluorine react what type of bond is formed
A) Metallic
B) Ionic
C) Covalent
D) Diatomic
Answer:
hi your answer should be B
Explanation:
Hope this helps!
Answer:
ionic
Explanation:
two metals that bond are considered ionic bonds
Question 17 (Essay Worth 5 points)
(02.06 HC)
Choose two spheres of Earth which interact when hot springs are formed. Use complete sentences to explain how they interact during this process
X2
= 12 Source
ус
cM
В І
U S XX T
.
Styles
Format
Font
Size
A- A -
Increase Indent
Answer:
geosphere and hydrosphere
Explanation:
which is the correct relationship among pressure, flow, and resistance?
Answer:
Flow is proportional to change in pressure and inversely proportional to resistance.
A heavy crate is pushed across a floor at a constant velocity. Friction is present between the crate and floor. During this motion, the force of friction is _?_ the force pushing the crate forward.
Question 3 options:
less than
greater than
equal to
Answer:
less than.
Explanation: because Friction is the resistance to motion of one object moving relative to another. which means it cant be greater because how would it be greater if its pushing forward when friction is the resistance.
THANKS FOR THE POINTS :D
when an individual charge flies through a *blank* field, a force is exerted on the charge and the path of the charge bends.
Answer:
"electric or magnetic"
F = q E force on charge q due to electric field E
F = q v x B force on charge q due to magnetic field B
A hair dryer transforms 10,000J of energy in 4s. What is its power?
Answer:
2500 WExplanation:
Power is the rate at which work is done and can be found by using the formula
[tex]p = \frac{w}{t} \\ [/tex]
p is power in Watts ( W)
w is the workdone in J
t is time in s
From the question
w = 10,000 J
t = 4 s
We have
[tex]p = \frac{10000}{4} = 2500 \\ [/tex]
We have the final answer as
2500 WHope this helps you
Which metals can be extracted from following ores (i) Argentite (ii) Haematite (iii) Chalcopyrite (iv) Bauxite
I hope it's helpful for you ☺️
1) iron
2) aluminium
3) silver
4) copper