A 1234 kg freight car moving at 6 m/s runs into a 2468 kg freight car at rest. They stick together upon collision. What was the final combined speed?
Answer:
2 m/s
Explanation:
Applying,
The law of conservation of momentum
Total momentum before collision = Total momentum after collision
mu+m'u' = V(m+m')............... Equation 1
Where m = mass of the first freight car, m' = mass of the second freight car, u = initial velocity of the first freight car, u' = initial velocity of the second freight car, V = final combined velocity/ speed.
make V the subject of the equation
V = (mu+m'u')/(m+m')........... Equation 2
From the question,
Given: m = 1234 kg, m' = 2468 kg, u = 6 m/s, u' = 0 m/s (at rest)
Substitute these values into equation 2
V = [(1234×6)+(2468×0)]/(1234+2468)
V = 7404/3702
V = 2 m/s
what type of object is called object at rest ? Write with example.
Answer:
ln physics, Rest is the state at which an object is stationary or not moving with respect to its surroundings, and is said to be at rest. An example would be a book lying on a table.
Answer:
When an object does not change it's position with respect to time it is said to be at rest.
Explanation:
Example- A person sitting on a chair or a book lying on a table.
Please note there is no such thing as absolute rest.
Take the example of a person A sitting in a moving bus. If the observer is in the bus then to him person A is at rest. However if the observer is is outside the bus then person A is in motion as the bus is moving.
Please mark me as brainliest.
What is a frequency in physics ?
Answer:
Frequency, in physics, the number of waves that pass a fixed point in unit time; also, the number of cycles or vibrations undergone during one unit of time by a body in periodic motion.
Explanation:
our sun and any star far away in another galaxy are too distant to feel a gravitational force between them
Answer:
Hello There!!
Explanation:
The answer is False.
hope this helps,have a great day!!
~Pinky~
Answer:
ture.
Explanation:
the correct answer is true.
10. Inertia causes your books on the car seat to continue moving forward even after you brake. TrueFalse 11. Tires with little or no tread do not have good traction on a wet, snowy, or icy road. TrueFalse 12. When driving on ice and snow, traction is poorest when the temperature is near 32 degrees F. TrueFalse 13. The more energy of motion that a car has, the less time and distance it will take to stop. TrueFalse 14. To help slow a car using engine braking, just take your foot off the accelerator. TrueFalse
10. True
11. True
12. True
13. False
14. False
Hope this helps!!
when work is done on a body its energy
a boy throws a ball straight up into the air. it reaches its highest point after 4 seconds.how fast was the ball going when it left the boy's hand
Answer:
Explanation:
The most important thing to remember about parabolic motion in physics is that when an object reaches its max height, the velocity right there at the highest point is 0. Use this one-dimensional motion equation to solve this problem:
v = v₀ + at and filling in:
0 = v₀ + (-9.8)(4.0) **I put in 4.0 for time so we have more than just 1 sig fig here**
0 = v₀ - 39 and
-v₀ = -39 so
v₀ = 39 m/s
The angle at which the refracted light ray lies
along the boundary of the two mediums, this
is the definition of
Answer:
Critical angle
Explanation:
The angle of incidence when the refracted angle is 90°; we have the critical angle at this point. At this point, the refracted ray lies between the boundary between the two medium, this is the angle just before total internal reflection occurs, as the refracted angle exceeds 90°, all rays are reflected. Hence, we can conclude that it is the largest angle at which reflection can still occur.
If a machin
has a mechanical advantage of 4, and an ideal mechanical advantage of 5. What is the
efficiency of the machine?
Answer:
Efficiency = 80%
Explanation:
Given the following data;
Mechanical advantage (MA) = 4
Ideal mechanical advantage (IMA) = 5
To find the efficiency of the machine;
Mathematically, the efficiency of a machine is given by the formula;
[tex] Efficiency = \frac {MA}{IMA} * 100 [/tex]
Substituting into the formula, we have;
[tex] Efficiency = \frac {4}{5} * 100 [/tex]
[tex] Efficiency = 0.8 * 100 [/tex]
Efficiency = 80%
Which grouping describes only the living part of an ecosystem?
A. environment
B .niche
C. community
D. habitat
Desde un globo se deja caer un objeto ¿Que velocidad tendra y que distancia habra caido al cabo de 12 segundos?
Answer:
velocidad = -117.6 m/s
Al cabo de 12 segundos, la distancia que el objeto habra caido es 705.6 m
Explanation:
Sabemos que un objeto que está en el aire es atraído por la fuerza gravitatoria. Si ignoramos fuerzas como la fricción del aire, entonces la aceleración del objeto será solamente la aceleración gravitatoria, que sabemos que es 9.8m/s^2
Entonces la aceleración del objeto es:
A(t) = -9.8m/s^2
Donde el signo menos se debe a que esta aceleración es hacia abajo.
Para obtener la velocidad, integramos sobre el tiempo:
V(t) = ( -9.8m/s^2)*t + V0
Donde V0 es la velocidad inicial, como el objeto se deja caer, la velocidad inicial es cero, entonces tenemos:
V(t) = ( -9.8m/s^2)*t
Para la posición integramos nuevamente:
P(t) = (1/2)*( -9.8m/s^2)*t^2 + P0
donde P0 es la posición inicial, en este caso podemos definir la posición inicial como cero, solo por comodidad, entonces la posición se escribe como:
P(t) = (1/2)*( -9.8m/s^2)*t^2
Ahora queremos saber:
La velocidad del objeto al cabo de 12 segundos. Acá simplemente reemplazamos t por 12s en la ecuación de la velocidad, así obtenemos:
V(12s) = ( -9.8m/s^2)*12s = -117.6 m/s
También queremos saber la distancia que ha caído al cabo de 12 segundos.
Esto es igual a la diferencia entre la posición para t = 12s y la posición para t = 0s
P(12s) - P(0s) = (1/2)*( -9.8m/s^2)*(12s)^2 - (1/2)*( -9.8m/s^2)*(0s)^2
= -705.6 m
Esto significa que el objeto ha caído 705.6 metros al cabo de 12 segundos.
The relationship between the equilibrant and the resultant vector is *
the equilibrant is equal in magnitude and in diredction
the equilibrant is equal in magnitude but opposite in direction
the equilibrant is different in magnitude and in direction
the equilibrant is different in magnitude but opposite in direction
Answer:
the equilibrant is equal in magnitude but opposite in direction.
Explanation:
In vector algebra, a resultant vector is a single vector that have the same effect as the effect of the net or algebraic sum of two or more vectors.
A resultant vector arises from finding the adding multiple vectors together.
When a group of vectors is replaced by a resultant vector, in order to keep the system of vectors at equilibrium, there is another vector which has the same magnitude as the resultant vector but acting in opposite direction to the resultant vector. This vector is called the equilibrant.
In all of the following examples, the quantity of the resource
being used by humans is affected EXCEPT–
A petroleum taken from the ground and burned for fuel.
B fresh water used for agriculture, recreation, and
tourism.
C wind power used to provide energy for homes and
businesses.
D metal ores mined and used to create building
materials.
Answer:
C wind power to provide energy for homes and businesses.
A car is moving with a uniform speed of 12.0 m/s along a straight path . What is the distance covered by the car in 20 seconds ?
Answer:
Explanation:
This one-dimensional equation is just a fancy way of saying d = rt. Filling in:
d = 12.0(20) so
d = 240 m
Questions:
1. A piano is moved up a ramp that is 3 m long with a force of 5
N. What is the work done on the piano? What is the name of the
simple machine for "ramp”? (6)
Formula
Show your steps (with
units)
Answer (with units)
Sentence
Simple Machine
Answer:
Workdone = 15 Nm
Explanation:
Given the following data;
Length of ramp (distance) = 3 m
Force = 5 N
To find the work done on the piano;
Mathematically, work done is given by the formula;
Workdone = force * distance
Substituting into the formula, we have;
Workdone = 5 * 3
Workdone = 15 Nm
II. The name of the simple machine for "ramp” is an inclined plane.
Typically, an inclined plane has a flat supporting surface that is set at an angle with an end higher than the other and it can be used to lift or lower an object.
Convert 0.4 cm to km.
In which direction does the frictional force act on the cube? A) upwards B) downwards C)in all the directions D) side to side
Answer:
D) side to side
Explanation:
The frictional force act on the cube in the side to side direction. The friction force acts opposite to the direction of the motion of an object which reduces its speed or sometimes prevent it from moving from one place to another. In order to reduce the force of friction, the body has to move by rolling instead of sliding and use of lubrication on the surface on which the object moves.
How are the lenses of 3-D glasses polarized?
Both lenses are polarized horizontally.
Both lenses are polarized vertically.
They are not polarized.
One lens is polarized horizontally, and one is polarized vertically.
Answer:
I think the last one which one lens is polarized horizontally, and one is polarized vertically
How do sports play a role in American Culture? Is this different from how sports play a role in other cultures?
PLEASE ANSWER QUICKLY!!!
Answer: American sports culture has a much greater appreciation of and emphasis towards collegiate and high school sports. This may be the strongest difference between American sports culture and every other countries' sports culture.
If the charge q is placed at the centre of the line joining two equal charges Q such that the system is in equilibrium then the value of q is?
Really need it, with a good explanation, will appreciate such answer.
Answer:
q is 0
Explanation:
Now another charge q is placed at the middle point of the line and the system is in equilibrium, that means net force on charge q is 0
Let's just suppose this situation, so it's like this;
Q --------------- q --------------- Q
Now, acc. to the question, the system is equilibrium which means that possibly both the Q should be exerting some pressure on the middle charge q, so let's suppose Q be +ve and q be -ve
The charge that we have kept at a certain distance something like this;
+Q --------------- -q --------------- +Q
<––– d ––– > <––– d ––– >
Now, we +Q will be exerting some force on the another +Q that it should be acc. to columbs law like this;
F = k × Q1Q2/r²
F = k × QQ/(2d)²
F1 = k × Q²/4d²
Also, when this +Q will exert force on -q, it could be written as;
F = k × Q1Q2/r²
F2 = k × Qq/d²
From the question, we know that the system is a equilibrium which means that these two force F1 and F2 will be equal to each other;
= k × Q²/4d² = k × Qq/d²
Eliminate the common values= Q/4 = q
Wait wait! The answer had still not came! remember this q is actually -q?= Q/4 = -q
= -Q/4 = q
So, the charge on q is -Q/4. :)
what is the definition for speed?
Explanation:
the rate at which someone or something moves or operates or is able to move or operate.
The energy diagram shows the changes in energy during a chemical reaction.
Which statement best describes the total energy change of the system?
Potential energy
n
Reaction progress
O A. Energy is released, and the products have higher potential energy,
O B. Energy is absorbed, and the reactants have higher potential
energy
O C. Energy is released, and the reactants have higher potential energy.
O D. Energy is absorbed, and the products have higher potential energy.
Statement B best describes the total energy change of the system. Energy is absorbed, and the reactants have higher potential energy.
What is a chemical reaction?One or more compounds, known as reactants, are transformed into one or more distinct substances, known as products. Such a process is known as a chemical reaction.
The energy diagram depicts how energy fluctuates during a chemical process.
The statement that best characterizes the overall energy change of the system is, "energy is absorbed, and the reactants have greater potential energy".
Hence, statement B best describes the total energy change of the system.
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Answer: Energy is RELEASED and the REACTANTS have HIGHER potential energy.
Explanation: I took the test
Long hair in the laboratory setting must be
always neatly groomed and brushed.
1
held away from the experiment.
tied back.
2
cut short.
3
The most appropriate measure is to tie back long hair to ensure it is safely secured and kept away from the experiment. The best answer is 3) tied back.
In laboratory settings, long hair poses a potential safety hazard due to the risk of hair getting tangled in equipment, chemicals, or flames. Therefore, it is important to tie back long hair to prevent it from coming into contact with hazardous substances or interfering with experiments.
1) Always neatly groomed and brushed and
2) held away from the experiment are good practices for general hygiene and cleanliness but may not adequately address the safety concern related to long hair in a laboratory setting.
4) cut short is not necessary as long as the hair is properly tied back and secured to minimize the risk of interference or contact with hazardous materials.
Thus, the most appropriate measure is to tie back long hair to ensure it is safely secured and kept away from the experiment. The best answer is 3) tied back.
To know more about the experiment concern:
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There are 2 pans of water, one has 10 mL in it and one has 500 mL. You add 3000 joules of energy, which one has the bigger change in temperature?
Answer:
The change in temperature is bigger for the first pan which contains 10 mL of water.
Explanation:
in one pan
mass, m = 10 mL = 10 g
in another pan
mass, m' = 500 mL = 500 g
Heat, H = 3000 J
Specific heat of water, c = 4.2 J/gC
Let the change in temperature in first pan is T and in the second pan is T'.
Use the formula of heat
H = m c T
For the first pan
3000 = 10 x 4.2 x T
T = 71.42 C
For the second pan
3000 = 500 x 4.2 x T'
T' = 1.42 C
So, the change in temperature is bigger for the first pan.
Which of the following statements is false?
A. Scalar quantities have size or magnitude only
B. Vector quantities have both magnitude and direction
C. Mass, length and time are all scalar quantities
D. Distance, velocity and acceleration are all vector quantities
Answer:
I think it might be c.
Explanation:
Hope it's right :3
Answer in the proper number of significant figures
789.5/8.32
Answer:
94.89182692 is the answer but there is only 3 in 8.32 so it rounds to 94.9
so 94.9 is the answer
hope this helps
have a good day :)
Explanation:
Which would increase the speed of a sound wave?
- A wave passes from a solid to a liquid while remaining the same temperature.
- The medium increases in temperature while remaining in the same phase.
- The medium decreases in temperature while remaining in the same phase.
- A wave passes from a liquid to a gas while remaining the same temperature.
Answer:
B. The medium increases in temperature while remaining in the same phase
Explanation:
Good luck on all your tests and Exams!
The sound wave will increase when the medium increases in temperature while remaining in the same phase.
What is a sound waves?Sound waves are composed of compressions and rare factions. Sound is a mechanical wave hence it moves by the vibration of air particles.
As such, the sound wave will increase when the medium increases in temperature while remaining in the same phase.
Learn more about sound waves:https://brainly.com/question/11797560
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Describe the mathematical relationship between the gravitational
potential energy of an object and its height above a reference point.
Answer:
∆p.e = mg∆h
Explanation:
Take height reference be h1 while height final be h2.
∆h = (h2 - h1)
m = m
g = g
•°• ∆p.e = mg(h2 - h1)
=> ∆p.e = mg∆h
Which of the following does not use analog signals?
Am radio
VGA connected monitor
iPod
Clock with a second hand
Answer:
iPod does not use analog signals
Explanation:
The work done to lift a 3kg mass to a
height of 10 m is
Answer:
The answer is 300Joules