A 1.0-kg object moving in a certain direction has a kinetic energy of 2.0 J. It hits a wall and comes back with half its original speed. What is the kinetic energy of this object at this point?
Lets calculate the initial speed of the block. We know that kinetic energy is given by:
[tex]K_0 =\dfrac{mv_0^2}{2}[/tex]
Solving for v₀:
[tex]v_0 = \sqrt{ \dfrac{2K_0}{m}} = \sqrt{ \dfrac{2(2\;J)}{1\;kg}} = 2\;m/s[/tex]
If the speed after it hits a wall is half its original speed then:
v = v₀/2 = 2 m/s / 2 = 1 m/s
Then the kinetic energy at this point is:
[tex]K =\dfrac{mv^2}{2} = \dfrac{(1\;kg)(1\;m/s)^2}{2} = \dfrac{1}{2}\;J = 0.5\;J[/tex]
The inetic energy of this object at this point is 0.5 J.
4. An isotope has 46 electrons, 60 neutrons, and 46 protons. Name the isotope.
14. It takes an airplane nearly ¾ of a mile to stop. Which law of motion is being used?
A) Newton's 1st Law
B) Newton's 2nd Law
C) Newton's 3rd Law
A golf ball starts with an initial velocity of 100m/s and slows at a constant rate of -8m/s2, what is its final velocity after 2s?
Vf = Vi+at
A. 20 m/s
B. 84 m/s
C. 16 m/s
Answer:
Answer: B. 84 m/s
Explanation:
Uniform Speed Motion
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time thus, the acceleration is constant.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the final speed is calculated as follows:
[tex]v_f=v_o+at[/tex]
The golf ball starts with an initial speed of 100 m/s and slows down at a=-8\ m/s^2. We are required to find the final speed at t=2 s:
[tex]v_f=100-8*2=100-16[/tex]
[tex]v_f=84\ m/s[/tex]
Answer: B. 84 m/s
An owl weighing 40N is sitting in a tree waiting to dive down to catch a mouse. If the owl's potential energy is 800 J with respect to the ground below, at what height above the ground is the owl?
h=PE/m
A. 81.63 m
B. 20 m
C. 2.04 m
Answer:
h = 20 m
Explanation:
Gravitational Potential Energy
Gravitational potential energy (GPE) is the energy stored in an object due to its vertical position or height in a gravitational field.
It can be calculated with the equation:
U=m.g.h
Where m is the mass of the object, h is the height with respect to a fixed reference, and g is the acceleration of gravity or [tex]9.8 m/s^2[/tex].
The weight of an object of mass m is:
W = m.g
Thus, the GPE is:
U=W.h
Solving for h:
[tex]\displaystyle h=\frac{U}{W}[/tex]
The weight of the owl is W=40 N and its GPE is U=800 J.
[tex]\displaystyle h=\frac{800}{40}=20[/tex]
h = 20 m
define temperature
Answer:
temperature is the degree or intensity of heat present in a substance or object.
Please mark me as Brainliest ........
In which direction does the gravity of the earth act?
why do the satellite not fall while revolving around the earth.
Answer:
Satellites don't fall from the sky because they are orbiting Earth. Even when satellites are thousands of miles away, Earth's gravity still tugs on them. Gravity--combined with the satellite's momentum from its launch into space--cause the satellite go into orbit above Earth, instead of falling back down to the groundv
Explanation:
What are the factors that influence the amount of elastic energy in an object
Anna got fed up and decided to put some of her classmates in a big box. She shoved Riley, Justin,
and Paul into the box and taped it shut. Anna couldn’t overcome the force of friction by herself, so she
asked some classmates to help push the box out the door. The force of friction of the floor on the box
was 450 N. If Anna and her classmates can each shove with a force of 34 N, how many students would it
take to make the box start moving out the door?
Answer:
like 14 students?
Explanation:
14x34= 476 and the force from them would have to go over 450N to overcome the force of friction and get the box moving
Mass of 80kg , velocity of 3 m/s , what is the momentum
Answer:
m times v =p
so 240 kg m/s that's the answer
4. Why do you think people in south Louisiana specialize in seafood?
Answer:
gang
Explanation:
yupppp
According to the law of conservation of mass, what is the mass of aluminum
oxide (Al2O3) formed in this reaction?
-
2A1 +
53.96 g
302
96.00 g
2A1203
?
A. 84.08 grams
B. 117.96 grams
C. 203.92 grams
D. 101.96 grams
D. 101.96 grams. Molar mass of Al2O3=2× Atomic mass of aluminium + 3× atomic mass of oxygen. =2×27+3×16=54+48=102g.
What happens when Al2O3 reacts?Sodium aluminate and water are produced when aluminum oxide Al 2 O 3 interacts with sodium hydroxide solution.Between 900 and 1100 ° C is the temperature at which this reaction occurs.Aluminum oxide functions as just an acid in this reaction.
How is Al2O3 produced from aluminum?Bauxite is the name of the aluminum ore (Al 2O 3).Bauxite is refined to create aluminum oxide, commonly known as alumina, which can be used to extract aluminum.Electrolysis is used to remove the metal, but first the aluminum oxide must be heated in order for electricity to flow through it.
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Answer: The CORRECT Answer is : 203.92 grams
Explanation: I took the test
If a charge at 60c flow in a conductor for 30 second then the current that flow in a conductor is
Answer:
Given - Charge = 60c
time = 30 sec
To find - current
Solution
Current = Charge/time
I = V/T
I = 60/30
I = 2 ampere
More to know -
I = Current
V = Charge
T = Time
Which vector is the sum of vectors a and ?
b
а
O
A.
B.
C.
Answer:
i would say D.
Explanation:
The sum of the given vector is option B as it is showing proper magnitude and direction.
What is a vector?A Euclidean vector, also known as a geometric vector or spatial vector, is a geometric entity with magnitude (or length) as well as direction in arithmetic, physics, and engineering.
Vector algebra allows vectors to be added to other vectors.
Physical concentrations can be represented using vectors. Vectors are most frequently used in physics to represent displacement, velocity, and acceleration.
Vectors are arrows that represent an amalgamation of magnitude and direction.
The operation of combining two or more vectors into a vector sum is known as vector addition.
The rule for vector addition of two or more vectors is given by the so-called parallelogram law.
Thus, the correct option is B as it is having magnitude and direction.
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A heat engine operating between the
temperatures T1 and T2 takes in Qı calories at
temperature T1 and gives up Q2 calories at
temperature T2. The efficiency of this heat
engine is
(Q1 - Q2)/Q2.
(Q1 - Q2)/Q1.
(T2 - T1/T2.
Q2/(Q1 - Q2).
O T1/(T1-T2).
Answer:
(Q1 - Q2)/Q1
Explanation:
The efficiency of any device can be given by the following formula:
[tex]Efficiency = \eta[/tex] = Output/Input
Now, for engine the output is the mechanical work that it does and the input is the heat that it absorbs. Let:
W = Work Done by the engine
Q₁ = Heat Absorbed by the System
Q₂ = Heat Rejected by the System (Because According to 2nd Law of Thermodynamics, engine can not convert the entire heat into work without rejection of some heat)
Therefore, the equation becomes:
[tex]\eta = \frac{W}{Q_{1}}[/tex]
but, the work can be written as the difference between the absorbed heat and the rejected heat. Hence,
[tex]\eta = \frac{Q_{1} - Q_{2}}{Q_{1}}[/tex]
Therefore, the correct option is:
(Q1 - Q2)/Q1
What compound is a product of photosynthesis?
Group of answer choices
Water
Carbon Dioxide
Glucose
Sunlight
Answer: Glucose
Explanation:
The Milky Way is our home galaxy. Which of the following are the main components of a galaxy?
A.
gravity, sedimentary rocks, and water
B.
ice, meteoroids, and minerals
C.
orbits, cores, and eclipses
D.
gas, dust, and stars
Answer:
D
Explanation:
most probable answers. I miss however here few things like eg. dark matter
please tell fast plzzzzzzz
Answer:
quartz watch wasn't in ancient times
Scuba divers use compressed oxygen gas to go diving. The oxygen's volume decreases as pressure is increased to fit more in an oxygen tank. What Gas Law is being applied in this situation?
Charles Law
Gay-Luassac's Law
Boyle's Law
Newton's Law
The electric force is a universal force that exists between any two charged objects What type of electric force exists between a
positively charged proton and a negatively charged electron?
A
an attractive force
B.
a repulsive force
C.
an attractive and a repulsive force
D
neither an attractive nor a repulsive force
Your friend writes you a postcard describing a bird she saw while on vacation.
You start creating a picture in your mind of what the bird looks like. What
active reading strategy are you using?
A. Monitoring and applying fix-up strategies
B. Using visual cues and text features
C. Making mental images
D. Summarizing
Answer:
it should be C.
Explanation:
Visualizing refers to the ability to create mental pictures in our mind based on the text we read or words we hear. When we visualize, we are tapping into our prior knowledge, making connections, gathering information and paying attention to detail. It is one of many skills that make reading comprehension possible.
how does the vertical component of a projectiles compare to the motion of vertical free fall when air resistance is neglected?
ANSEWR FOR BRAINLIEST
When lifting weights, technique and posture are less importance the than amount of weight you lift?
A. true
B. false
Answer:
B. False
Explanation:
Without good technique and posture you can end up getting injured.
Question 9 of 20
Which sentence best describes the function of an electric motor?
A. An electric motor uses electrical energy to produce magnetic
force.
B. An electric motor uses electrical energy to produce mechanical
energy
C. An electric motor uses mechanical energy to produce electrical
energy
D. An electric motor uses magnetic force to produce electrical
energy
Option B. An electric motor uses electrical energy to produce mechanical energy.
An electric motor is used to transform electric electricity into mechanical power. An electric-powered motor is an electrical device that converts electric energy into mechanical electricity.
Maximum electric-powered motors operate thru the interaction among the motor's magnetic field and electric-powered contemporary in a wire winding to generate force inside the form of torque implemented on the motor's shaft.
Electric motors are devices that convert electrical strength into mechanical power, commonly in the form of rotational motion. In easy terms, they may be devices that use electric powered power to generate reason strength.
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A car and driver weighing 5060N passes a sign stating "Bridge out 27.5 meters ahead." She slams on the brakes and the car decelerates at a constant rate of 14 m/s^2. The acceleration of gravity is 9.8 m/s^2. What is the magnitude of the work done stopping the car if the car just stops in time to avoid diving into the water?
Answer in units of J.
Answer:
198785.714286 Joules
Explanation:
[tex]W=f*d[/tex]
[tex]F=ma\\F=516.326530612*-14\\F=-7228.57142857 N\\[/tex]
To find work:
Now that the force and the distance are known, plug and chug:
[tex]W=f*d\\W=-7228.57142857*27.5\\W=-198785.714286J[/tex]
Note that the question is asking for the magnitude of work, so the negative can be discarded as it is a directional component.
So, your answer is
198785.714286 Joules
Based on the law of conservation of energy, which statement is correct?
Answer:
D. Energy in an isolated system remains constant
General Formulas and Concepts:
Physics
Law of Conservation of Energy - Energy is neither created or destroyedExplanation:
According to the Law of Conservation of Energy, it cannot be created or destroyed.
Therefore, we can eliminate choices A and B right off the bat.
We need to choose between C and D. We know that even though energy cannot be created or destroyed, it can be changed into a different form. Therefore, the correct answer is D.
Which of the following is an example of a double replacement reaction?
A. 3Fe + 2O2 → Fe3O4
B. BaCl2 + K2CO3 → BaCO3 + 2KCl
C. NiCO3 → NiO + CO2
D. Cl2 + 2NaBr → 2NaCl + Br2
Answer:B
Explanation:please like this bc I just did it and got it right
Four different objects are placed on a number line at 0. The chart describes the motion of each object.
Object
Motion
W
3 units left, then 3 units right
Х
6 units right, then 18 units right
Y
8 units left, then 24 units right
Z
16 units right, then 8 units left
Using the information in the chart, the distance and displacement of each object can be determined. Which object has
a distance that is three times as great as its displacement?
W
Х
Z
Answer:
Z
Explanation:
Answer:
Z
Explanation:
I took the test on edge and got it right. Good luck :)
a boy claps his hand when he is 420m from the bottom of the cliff. he heard the eco after 2.4 second. what is the speed of sound
Answer:
350 m/s
Explanation:
In order for Boy to hear the sound, the sound has to travel from his hands to the cliff, and then BACK to him from the cliff to his ears.
So the sound has to travel (2 x 420m) = 840 m.
Speed = (distance) / (time)
Speed = (840 m) / (2.4 sec)
Speed = 350 m/s
Answer:
350 m/s
Explanation:
lily can travel 60 miles in 1.5 hours. if her speed is reduced by 5 mph. how far can she travel in 3 hours?
Answer:
3 hours.
Explanation:
If speed is reduce of 5, then she drive at 35 mph.
so 35*3 = 105 miles in 3 hours.
Therefore, we get 3 hours.