A 12 kg object speeds up from an initial velocity of 10 m:s-1
north to a final velocity of 15 m.s-north. Calculate the
change in momentum.
Select one:
a. -60 kg.m/s
b. 60 kg.m/s
C. -80 kg.m/s
d. 300 kg.m/s
Momentum = m • v
Original momentum = m • 10 m/s north
Final momentum = m • 15 m/s north
Change = m • (15 - 10) m/s north
Change = m • +5 m/s north
Change = +60 kg-m/s north
1) An object is dropped from the top of tower of hight 156.8m and at the same time another object is thrown vertically upward with the velocity of 77.1 m/s from the feetof tower,when and where the object meet
Answer:
The objects meet after 2.033722438s, at a height 136.5334679m from the ground.
Explanation:
Call the object being dropped A and the object being thrown B.
When the objects meet, the time ('t') for both objects will be equal, and the sum of their distances will be equal to 156.8m.
Figure out the distance for A in terms of time, t:
s = ut + (1/2)at²
= 0t +(1/2)(9.8)t²
=4.9t²
Figure out the distance for B in terms of time, t:
s = ut + (1/2)at²
=(77.1)t + (1/2)(-9.8)t²
=77.1t - 4.9t²
We now adding the distances gives us 156.8, so can write:
(4.9t²) + (77.1t - 4.9t²) = 156.8
77.1t = 156.8
∴ t = 2.033722438s
To find the distances, plug in this value for t:
For A: 4.9t² → 20.26653209m
For B: 77.1t - 4.9t² → 136.5334679m
The objects will meet 155.2 meters below the top of the tower after 15.7 seconds.
What is the height?The formula to calculate the time it takes for the object thrown upwards to return to the ground:
Time = 2 * Initial velocity / gravitational acceleration
Plugging in the values given in the question, you can calculate the time as follows:
Time = 2 * 77.1 m/s / 9.8 m/s^2 = 15.7 seconds
To determine when and where the objects meet, you can use the following formula to calculate the height of the object thrown upwards at any given time:
[tex]Height = Initial velocity * time - (1/2) * gravitational acceleration * time^2[/tex]
Plugging in the time calculated above and the initial velocity and gravitational acceleration given in the question, you can calculate the height of the object at the time it returns to the ground as follows:
Height = 77.1 m/s * 15.7 s - (1/2) * 9.8 m/s^2 * (15.7 s)^2 = -1.6 meters
This means that the object thrown upwards returns to the ground 1.6 meters below the point where it was launched. The object dropped from the top of the tower will also have fallen a distance of 156.8 meters in the same amount of time, so the two objects will meet at a point 156.8 meters - 1.6 meters = 155.2 meters below the top of the tower
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There are screws all around you. Name five examples of screws that you see in everyday life? Think broadly!
Screw pump, Drill Machine, Bottle Caps, Faucets and Car Jack are the five examples of screws that we see in everyday life.
What is screw?Screw is defined as a short, sharp-pointed metal pin with a raised helical thread present round it. It has a slotted head that is used to join things together by rotating it so that it pierces wood and is held tightly on its place. Screw is used in many materials in order to join two frames or bodies with each other. Without this screw, we can't imagine many materials to work together so screw has very high importance.
So we can conclude that Screw pump, Drill Machine, Bottle Caps, Faucets and Car Jack are the five examples of screws that we see in everyday life.
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From Smallest to Largest
Moon
asteroid
meteorite
meteoroid
A person weighing 600N runs up a flight of stairs. It takes the person 10s to get to the top. They are 6m higher at the top of the stairs. How much power was used?
Answer:
[tex]Power = 360W[/tex]
Explanation:
Given
[tex]Force = 600N[/tex]
[tex]Time = 10s[/tex]
[tex]Height = 6m[/tex]
Required
Determine the power used
First, we need to calculate the work done to climb the stairs.
[tex]Word = Force * Distance[/tex]
In this case, the distance represents the height of the stairs.
So:
[tex]Work = 600N * 6m[/tex]
[tex]Work = 3600J[/tex]
Next, we calculate the power using:
[tex]Power = \frac{Work}{Time}[/tex]
Substitute values for Work and Time
[tex]Power = \frac{3600J}{10s}[/tex]
[tex]Power = 360W[/tex]
Hence, the power used by the person is 360 watts
A circular track has an inside cirumference of 220m. If the width of track is 3.5m, find its outer circumference.
Answer:
Lc = 242 [m]
Explanation:
The circumference is defined as the circumference length of a circle, this length can be calculated by means of the following equation.
[tex]L_{c}=2*\pi *r[/tex]
where:
Lc = circumference length = 220 [m]
r = radius [m]
Now we can clear r
[tex]r=\frac{L_{c}}{2*\pi } \\\\r = \frac{220}{2*\pi }\\\\r = 35.01 [m][/tex]
Now we can determine the outer radius with the inner diameter plus the width of the track.
R = r + 3.5
R = 35.01 + 3.5 = 38.51 [m]
The outer circumference is:
[tex]L_{c} = 2*\pi *38.51 \\L_{c} = 242 [m][/tex]
i really need help with this
Answer:
The Moon
Explanation:
F=MA
160=98a
a=1.632563061m/s²
This value is closest to the Moon's value
A baseball is thrown horizontally at a rate of 40m/s toward a home plate 18.4 m away. How far below the launch height is the ball when it reaches home plate
Answer:
1.03684mExplanation:
Using the formula for calculating range expressed as;
R = U√2H/g where
R is the distance moves in horizontal direction = 18.4m
H is the height
U is the velocity of the baseball = 40m/s
g is the acceleration due to gravity = 9.8m/s²
Substitute the given parameters into the formula and calculate H as shown;
18.4 = 40√2H/9.8
18.4/40 = √2H/9.8
0.46 = √2H/9.8
square both sides;
(0.46)² = (√2H/9.8)²
0.2116 = 2H/9.8
2H = 9.8*0.2116
2H = 2.07368
H = 2.07368/2
H = 1.03684m
Hence the ball is 1.03684m below the launch height when it reached home plate.
You run
completely around a 400m track in
100s. What was your average velocity?
Answer:
About 410
Explanation:
Answer:
4 m/s
Explanation:
Divide 400 m by 100 s to get 4 m/s. It also equals about 8.95 mph, 8.94775 mph to be exact.
Which option is the smallest particle that represents the compound carbon
dioxide?
A. A carbon dioxide molecule B. A carbon dioxide atom
C. A carbon atom and an oxygen atom
D. A carbon ion and an oxygen ion
HELPPPPP
PLEASE I NEED THIS ANSWER FASTTTT
Answer:The answer is A
Explanation: You can instantly eliminate b and d because an ion isn't mentioned, and it is impossible to have a carbon dioxide atom. C is incorrect because there has to be two oxygen's to create a carbon dioxide molecule.
Answer:
D. A carbon dioxide molecule
Explanation:
The U-tube contains a coloured liquid of density 9.6 x102 kg/m3. If the difference in height between the liquid levels in the two arms of the U-tube is 0.16m, calculate the excess pressure (above air pressure) in the cylinder. (Take g = 10 N/kg)
Explanation:
P = ρgh
P = (9.6×10² kg/m³) (10 N/kg) (0.16 m)
P = 1536 Pa
Rounded to two significant figures, the pressure is 1500 Pa, or 1.5 kPa.
Explain why the focal point of a diverging lens is called a virtual focal point.
Which reaction is an acid-base neutralization reaction?
A. Mg + 2HCl → MgCl2 + H2
B. HCl + NaOH → NaCl2 + H2O
C. SiCl4 → Si2 + 2Cl2
D. N2 + 3H2 → 2NH3
Answer:
option B is correct
Explanation:
neutralization is the reaction between acid and base to produce water and salt therefore option B is correct
carbon has six protons. which model shows a neutral atom of carbon?
Answer:
It should have 6 electrons to be a neutral carbon atom
Calculate the average induced voltage between the tips of the wings of an airplane flying above East Lansing at a speed of 885 km/h. The wingspan of the airplane is 50.4 m, the vertical component of the Earth's magnetic field is 6.90×10-5 T.
Answer:
=0.855V
Explanation:
The induced voltage can be calculated using below expression
E =B x dA/dt
Where dA/dt = area
B= magnetic field = 6.90×10-5 T.
We were given speed of 885 km/h but we will need to convert to m/s for consistency of unit
speed = 885 km/h
speed = 885 x 10^3 m/hr
speed = 885 x 10^3/60 x60 m/s
speed = 245.8 m/s
If The aircraft wing sweep out" an area
at t= 50.4seconds then we have;
dA/dt = 50.4 x 245.8
= 123388.32m^2/s
Then from the expression above
E =B x dA/dt substitute the values of each parameters, we have
E = 6.90 x 10^-5 x 12388.32 V
E =0.855V
Hence, the average induced voltage between the tips of the wings is =0.855V
how does the electric current of an AC generator differ from that of a DC generator ?
A- it flows through the permanent magnets
B- it is much stronger
C- it is much weaker
D- it constantly reverses direction
The difference between the AC and the DC is that the AC current is always reversing. Option D
What is a generator?We have to know that the term generator has to do with a device that can be used in the production of electricity. The principle upon which the generator works is the principle of the electromagnetic induction.
Now we know that when we have a DC generator, the current that it is able to supply can be found to be constant but in the case of the AC generator, there is a constant change since the direction is reversing.
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The electric current of an AC generator differs from that of a DC generator in that it constantly reverses direction.
The correct option is D.
What are AC and DC generators?A mechanical device known as an AC generator transforms mechanical energy into AC or alternating current electrical power. Periodically, the electrical current in an AC generator changes direction.
A mechanical device known as a DC generator transforms mechanical energy into DC or direct current electrical power. The electrical current in a DC generator flows in one direction.
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An electric heater takes 1.2kwh in 30min at 120V having an efficiency of 99%.The heat energy required boil a certain amount of water is 99KJ.If the current taken by heater is 20 amp at 120V.Find the time required to boil water?
Answer:
Explanation:
Power of the heater = P watt .
P x .5 = 1200
P = 2400 W
If resistance of heater R
V² / R = 2400
120²/ R = 2400
R = 6 ohm .
heat to be produced = 99000 J
Current be I
I²R t x .99 = 99000
20² x 6 x t x .99 = 99000
t = 41.67 s
FOR 45 POINTS PLS ANSWER FAST
1. coefficient of friction
force that opposes a sliding object
2. drag
a force that resists motion
3. friction
friction between a solid and a liquid or gas
4. rolling friction
a force that develops when a mass is accelerated by gravity; stated as Fw = mg
5. sliding or kinetic friction
force that opposes a rolling object
6. starting or static friction
force that opposes the start of motion
7. weight
the ratio of the force necessary to move an object (or keep it moving) and the normal force
Answer:
Other than gravity, the most commonly encountered force is what or the force that resists motion.
friction
the ratio of the force necessary to move an object (or keep it moving) and the normal force
coefficient of friction
friction between a solid and a liquid or gas
drag
a force that resists motion
friction
the force that presses two surfaces together and is directed perpendicular to the contact surface; on a level surface, its magnitude is equal to the force of the object's weight but in the opposite direction
normal force
force that opposes a rolling object
rolling friction
force that opposes a sliding object
sliding or kinetic friction
force that opposes the start of motion
starting or static friction
a force that develops when a mass is accelerated by gravity; stated as Fw = mg
weight
Friction is a force that resists what
motion
It occurs when a surface in motion rubs against another what
surface
What acts parallel to the surfaces that are moving against one another and in the direction opposite to the direction of the motion (represented by F).
Friction
riction is caused by the interaction of the what or what of each object sliding over each other.
atom or molecules
he more contact the atoms are able to make, the greater the what
frictional effect
A what surface will produce more friction (resistance) than a smooth surface
rough surface
The high points on one surface interact with the high points on the other surface allowing atoms and molecules to form temporary what
intermolecular bonds
The more bonds that are allowed to form, the greater the what
friction
he force that opposes the start of motion is referred to as what
starting or static friction
This force is caused by the what that form between two surfaces
tiny bonds
The pull required to keep the block moving at a constant speed in the example above is due to what
sliding or kinetic friction
What occurs as tiny intermolecular bonds are constantly being formed and broken.
Sliding friction
Sliding friction is also affected by the weight of the object and another force called the what
normal force
What is the force of the contact surface pressing opposite the weight of the object, as seen in the diagram below.
normal force
The normal force is always perpendicular to the what
contact surface
The ratio between the sliding friction and the perpendicular normal force is called the what of sliding friction
coefficient
What is represented by the Greek letter mu, μ,
coefficient
he third type of friction that can exist between solid surfaces is what or the force that opposes a rolling object
rolling friction
Friction can also exist between what
solids liquids and gases
Gases and liquids, such as air and water, offer what
resistance to motion
the opposing force between a solid and a liquid or gas
drag
5. Suppose you have three identical drinking cups: one made of plastic, one foam, and one paper.
You want to find out which cup will keep your hot cocoa hot for the longest time.
a. Phrase a formal question for this experiment.
b. What is your hypothesis?
c. What is the experimental variable?
d. What are three important control variables?
e. What type of evidence will you collect to test your hypothesis?
f. Challenge: Conduct your experiment and summarize your findings.
Answer:
a) How the cooling speed changes with glasses of different materials?
b) The glass material influences the cooling rate
c) temperatures initial, final and the time
d) the control variable is time
e)temperature of the beverage heated in a given time
f) best material for insulation was expanded
Explanation:
This is a problem of how to formulate an experiment using the scientific method
a) a question for this problem to follow.
How the cooling speed changes with glasses of different materials?
b) the hypothesis of the experiment is:
The glass material influences the cooling rate
c) we have the independent variable that the experimenter controls
the material of the glass, the initial temperature of the drink and the cooling time
the dependent variable is the one that is measured
the temperature of the drink and the time
d) the control variable is time
e) the evidence would be the temperature of the beverage heated in a given time
f) When conducting the experiment, the thermal conductivity of the material is the most important factor, the one with the lowest thermal conductivity is the one that keeps the drinks longer
in general, the conductivity ends of paper 0.24 W/m K and that of plastic is 0.06 W / m K, of expanded 0.03 W / m K
From these values it is experienced that the best material for insulation was expanded
What is the final speed of an object that starts from rest and accelerates uniformly at 3.0 meters per second2 over a distance of 6.0 meters? (1) 8.0 m/s (2) 6 m/s (3) 16 m/s (4) 64 m/s
Answer:
16 m/s sir
Explanation:
because i am in collage
If the weight of an object on the moon is 1/6 of the weight of an object on earth. What
would be the weight of an object on the moon who has the weight of 4800 N on earth?
Answer:
1200 N
Explanation:
Answer:
1200N
Explanation:
Suppose a body of mass "m" and its weight on the moon is Wm (where W is the weight and "m" is the moon ;which means weight on the moon).Mass of the moon is "M"
and its radius is "R"
Weight of an object on the moon = "F"(Force)with which the moon pulls.
Wm = GM*m/r2
Weight of the same object on the earth is We(where W is the weight and "e" is the earth; which means weight on the earth).
Mass of the earth is 100 times of that of the moon.
Radius of the moon = R
Radius of the Earth = 4R
Weight of the object on the moon =
We = G100M*m/(4R)2(Pronounced 4 R square)
We = G100M*m/(16R)2(Pronounced 16 R square)
Wm/We = G * M * m * 16R2/R2 * g * 100M * m
=16/100
Therefore, 4800N on earth= 1200N on moon
a librarian pushes a 35kg box of books across the library floor. if the carpet resists with a friction force of 91N, what force must be applied by the librarian to accelerate the box at a rate of 0.50m/s
Answer:
F = 108.5 [N]
Explanation:
To solve this type of problem we must use Newton's second law, which tells us that the sum of forces must be equal to the product of mass by acceleration.
ΣF = m*a
where:
ΣF = sum of forces [N]
m = mass = 35 [kg]
a = acceleration = 0.5 [m/s²]
f = friction force [N]
F - f = m*a
F - 91 = (35*.5)
F = 91 + 17.5
F = 108.5 [N]
Why is it important to lean forward and listen
Gregory's apartment catches fire, and he has to replace his sofa. Which policy will most likely cover the cost of replacing the sofa?
Answer:
Gregory's apartment catches fire, and he has to replace his sofa. Which policy will most likely cover the cost of replacing the sofa
Skin cells have the function of protecting the body. What is the function of muscle cells?
Answer:
Skin serves as a protective barrier, a way to sense the world, and a layer that keeps nutrients and water inside the body. Four types of cells make up the skin, and they are produced mainly in the epidermis near the basement membrane. Keratinocytes contain structural keratin and make up the bulk of the epidermis.
Explanation:
Please help with this!
On the way down the ball's velocity is Positive 9.8.
Option A) is the correct answer.
What is velocity:?
This refers to the speed at which an object moves in a given direction. It unit is meters per secocond, m/s.
What is acceleration?
This is the rate of change of velocity with respect to time. The speed and direction of the accelerating object are also very important. It unit is meters per second square, m/s².
What is Gravity?
This is the force that pulls a body toward the center of the earth. This force causes objects to fall freely. This free-falling object has an acceleration of 9.8m/s downward the earth. This is called acceleration gravity.
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While rowing in a race, John uses his arms to exert a force of 155 N per stroke
while pulling the oar 0.7500 m. How much work does he do in 25 strokes?
Answer:
Workdone = 2906.25J
Explanation:
Given the following data;
Force, F = 155
Distance, d = 0.75
Stroke, s = 25
Mathematically, work done is given by the formula;
Work done = force * distance * stroke
[tex] W = F * d * s[/tex]
Where,
W is the work done
F represents the force acting on a body.
d represents the distance covered by the body.
s is the number of strokes.
Substituting into the equation, we have;
[tex] Workdone = 155*0.75*25[/tex]
Workdone = 2906.25J
Iron filings were sprinkled around these two magnets. What do the iron filings
show?
O A. They show that magnetic field lines point away from the north
pole of magnets.
B. They show the pattern made by the magnetic field lines around the
magnets
C. they show that magnetic field lines often cross over each other when magnets repel
D. they show the locations of the magnetic domains in the magnets
please help no ones questions match mine!!!
Answer:
B. They show the pattern made by the magnetic field lines around the
magnets
Explanation:
Using iron fillings, the pattern of the magnetic field lines around a bar magnet can be known.
Magnetic field lines are the line of force around a bar magnet.
These iron fillings will trace the pattern of the magnetic field around the magnet. The domains of the iron fillings begins to align and orient with that of the prevailing magnetic field around. Those areas with the strongest force will attract more fillings and those far away will attract lesser fillings.Answer:
B
Explanation: E Z
what can i do to recycle?
Answer:
You could throw away the following items:
Mixed paper: Newspaper, magazine, junk mail, cardboard, frozen food packaging, wrapping paper, paper bags, etc.
Cans: aluminum, foil, tin, steal, aerosol (empty without pressure) and metal food trays. ...
Unbroken glass: Wine bottles, bottles and jars.
Plastic: Rigid containers like milk jugs, shampoo or water bottles.
Hope this helped
does anyone know the answer ?
Answer:
it is 2 and 3 trust me I gotcha