Dimentional analysis is very important in physics, because it allows finding errors in equations. We find that the following true equations
a) F= m a
b) x = 2 a t²
c) E = [tex]\frac{1}{2} }\ m \ a \ x[/tex]
d) E = m a x
The fundamental units in mechanics are;
the length [L] whose unit is the meter
The time [T] that has the second as a unit
The mass [M] with fundamental unit the kilogram (kg)
all other quantities are derived from these three fundamental units, for example velocity is
v = x / t
we replace the units
[v] = [L] / [T]
so the units of velocity are the distance between time.
This exercise uses the units of various quantities and asks to find if the equations are dimensionally correct.
Let's substitute the units in each expression
a) F = m a
[M] [L] / [[T] ² = [M] [L] / [T] ²
the two sides of the expression are equal therefore the equation is correct
b) x = 2 a t²
scalar quantities have no units
[L] = [L] / [T] ² [T] ²
[L] = [L]
the two sides are equal, therefore the equation is correct
c) E = ½ m a x
[M] [L] ² [T] ² = [M] [L] [T] ² [L]
[M] [L] ² [T] ² = [M] [L] ² [T] ²
the two sides are equal the equation is correct
d) E = m a x
since scalar quantities have no units, this expression is equivalent to the expression in part c, therefore it is correct
e) F = F x / m
[M] [L] / [T] ² = [M] [L] / [T] ² [L] / [M]
[M] [L] / [T] ² = [L] ² / [T] ²
the two sides are different so the equation is false
In the dimensional analysis we find that expressions are true a, b, c, d and we see that the expression e is false
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a car is traveling north. can its acceleration vector ever Point South? explain
When a car is traveling north, its acceleration vector can point south when it is slowing down.
A vector quantity has both magnitude and direction. The direction of a vector is always shown by the direction to which the arrow points.
If the car is travelling north, the direction of the acceleration vector will continue to point northwards.
However, when the car slows down, the direction of the accelerating vector will now point southwards.
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If mass of body is 10 kg then its weight on moon is:
Please help
Answer:
moon gravity is about one sixth of earth gravity
W = 10(9.8/6) = 16 N
Vector A is 12.4 cm long and is pointing in a direction which is 73.0 degrees from the positive axis, measured in a counter-clockwise direction. Vector B is 15.1 cm long and is pointing in a direction which is 156.0 degrees from the positive axis, measured in a counter-clockwise direction. Calculate the x and y components of these vectors.
Answer:
Explanation:
I will ASSUME you mean the positive X axis.
Ax = 12.4cos73.0 = 3.6254...
Ay = 12.4sin73.0 = 11.8581...
Bx = 15.1cos156.0 = -13.7945...
By = 15.1sin156.0 = 6.1417...
The x components of vector A is 3.62 cm and the y components of vector A is 11.85 cm
The x components of vector B is -13.79 cm and the y components of vector B is 6.14 cm
The given parameters;
length of vector A = 12.4 cm
length of vector B = 15.1 cm
angle of vector A from the positive x-axis = 73⁰
angle of vector B from the positive x-axis = 156⁰
To find:
the x and y components of these vectorsThe x components of vector A:
[tex]A_x = A \times cos (\theta)\\\\A_x = 12.4 \ cm \times \ cos (73)\\\\A_x = 3.62 \ cm[/tex]
The y components of vector A:
[tex]A_y = A \times sin (\theta)\\\\A_y = 12.4 \ cm \times \ sin (73)\\\\A_y =11.85 \ cm[/tex]
The x components of vector B:
[tex]B_x = B \times cos (\theta)\\\\B_x = 15.1 \ cm \times \ cos (156)\\\\B_x = -13.79 \ cm[/tex]
The y components of vector B:
[tex]B_y = B \times sin (\theta)\\\\B_y = 15.1 \ cm \times \ sin (156)\\\\B_y = 6.14 \ cm[/tex]
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TRUE OR FALSE
A moderate risk environment has protected and unprotected left turn
Answer:
Explanation:
True
This same car gets pulled over for speeding, and goes from 68 m/s to 0 m/s in 14
seconds. What is the acceleration for this car?
a. What is the DIRECTION of the acceleration vector for this car and why
does this make sense?
Answer:
the acceleration of the car is -4.9m/s2.
the direction is opposite to the actual direction, since the acceleration is negative.
Nate throws a ball straight up to Kayla, who is standing on a balcony 3.8m above Nate. When she catches it, the ball is still moving forward at a speed of 2.8m/s. With what initial speed did Nate throw the ball?
Answer:
2.8s
Explanation:
because from the presure
if an equation is demensionally correct does this mean that the equation is true
Explanation:
If an equation is dimensionally correct, it does not mean that the equation must be true. On the other hand, when the equation is dimensionally correct, the equation cannot be true. Dimensional analysis is a technique used to check whether a relationship is correct
The diagram below represents the forces acting upon a rightward-moving object.
Each arrow represents a force; the length of the arrow represents the strength of
the force.
Answer:
Explanation:
The up and down arrows appear to me to be of the same length, therefore there is no up or down acceleration.
There are no right or left arrows, therefore there is no right or left acceleration.
The mass moves with constant velocity.
This could be the free body diagram of an ice puck sliding across a frictionless ice surface.
The down arrow is the puck weight. The up arrow is the normal force of the ice on the puck.
A friction force would be represented by a horizontal arrow to the left for the rightward moving mass. It's not there.
If something were increasing the rightward speed, like a bottle rocket attached to the puck, it would be represented as a right facing arrow.
Suppose you're studying levels of job stress and measures of job efficiency in a nursing home. Which one of the following
statements best represents a data comparison that demonstrates a positive correlation?
O A. As job efficiency decreases, stress levels increase.
O B. As job efficiency increases, stress levels decline.
O C. As stress levels increase, job efficiency declines.
O D. As stress levels increase, job efficiency increases.
Answer:
B
hmgzzvmfzfjlpdyktdkdtdk
Answer:
b
Explanation:
flgifidfididicudifidififificiduxididixuduxi
"Force" can be defined as a push or a
O pull
O grab
Answer:
pull is your answer.
I HOPE your day goes great.
.Write the meaning of following words:
a) gale
b) billows
c) raging
d) evil
Answer:
a strong wind.
showing rage.
a large undulating mass of something, typically cloud, smoke, or steam.
profoundly immoral and wicked.
Explanation:
please mark me brainliest pleasewhich of the following are not vector directions?
A. 35 degrees north of east
B. North
C.Outside 45 degrees
D. 35 degrees inside
Answer:
Hello! Your answer is BELOW.
Explanation:
Outside 45 degrees
35 degrees inside
Hope I helped Hope you make an 100%
-Amelia♥
The Kinetic Molecular Theory (KMT) is discussed in this lesson, and it helps us understand the behavior of gases. From what we learned, which of these statements are consistent with KMT?
A. Due to the large amount of empty space between gas molecules/atoms, the density of a gas is very low.
B. Gas molecules are in constant, random motion, so they take the shape and volume of whatever container they are in.
C. Since atoms are mostly empty space, gases can be compressed.
D. Gas molecules/atoms collide with each other and surfaces without losing energy. E. All of the above statements are consistent with KMT.
Answer:
Explanation:
for a.;
Kinetic molecular theory assumes the collision of particles with each other and walls of container as perfectly elastic, that is why no particle loses energy.
for b.;
Kinetic molecular theory assumes that particles are of very small size incomparison with the size of container and far apart from each other that is why their density is very low. because density is described as
Density = Mass/Volume
So, one can imagine that in a big container, entire mass of all gas particles is very low as compared to the volume of container. So the gas have very low density
For c.;
Gases assume shape of their container because they are freely moving with in a container
For d.;
For statement in "b", one can easily understand that because according to kinetic molecular theory, particles are very small and at great distances, so they are compressible against any external pressure applied
the processes used to gain knowledge are called ____ development
what is a law in physics?
Answer:
By nature, laws of Physics are stated facts which have been deduced and derived based on empirical observations. Simply put, the world around us works in a certain way, and physical laws are a way of classifying that “working.”
A thin uniform bar has a moment of inertia II about an axis perpendicular to it through its center. If both the mass and length of this bar are doubled, its moment of inertia about the same axis will be:_____.
A. 2I.
B. 4I.
C. 8I.
D. 16I.
E. I/16.
Answer:
C. 8I.
Explanation:
As moment of inertia for a bar is proportional to the product of its mass and the square of its length, doubling the mass will double the moment of inertia. Doubling the length will quadruple the moment of inertia. Doing both will make the moment of inertia 2(4) = 8 times larger
How much is the velocity of a body when it travels 600m in a straight line in 5 min. Calculate in m/s unit.
[tex] \large \mathfrak{Answer : }[/tex]
Velocity of the body traveling 600 m in 5 min = 300 seconds is :
[tex] \dfrac{600}{300} [/tex][tex]2 \: \: m/s[/tex]Describe three ways that adults continue to guide children's emotions during the school-age
years.
In compressed state, a spring 3.00 meters long hanging from the ceiling has a potential energy of 2.0 joules. If the entire potential energy is used to release a ball of mass 1.2 kilograms vertically downward, then what is the kinetic energy of the ball when it reaches the ground?
A.
1.2 joules
B.
4.9 joules
C.
2.0 joules
D.
6.8 joules
Answer:
Option C
Explanation:
2.0 Joules
Hope it helps!
a student balances a 1.5kg of broom by placing her finger 1.4m from the end of the broom handle. How far from the broom handle would she have to balance the broom if she hung a 400g mass from the end of the broom handle?
The broom handle that she have to balance if she hung a 400g mass from the end of the broom handle is 5.24m
This problem is centered on moment. Moment is the turning effect of a force about a point. It is expressed as:
Moment = Force× Distance
According to principle of moment, the sum of clockwise moment is equal to sum of anticlockwise moment at shown
M1d1 = M2d2
Given the following
M1 = 1.5kg
d1 = 1.4m
M2 = 400g = 0.4kg
d2 is required
Substitute
1.5(1.4) = 0.4d2
2.1 = 0.4d2
d2 = 2.1/0.4
d2 = 5.24m
Hence the broom handle that she have to if she hung a 400g mass from the end of the broom handle is 5.24m
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If you are given force and time, you can determine power if you can know
(a) watts
(b) energy
(c) distance
Answer:
joules/energy.
Explanation:
power is defined as the rate of work. Hence power=work/time, then you obtain Watts.
Work is the product of force and displacement.
Which substance is a gas at room temperature and atmospheric pressure?
A. Hg
B. CH
C. C2H5OH
D. H20
Answer:
Explanation:
A) Hg is mercury, a metal that is mostly liquid at STP (Standard Temp and Pressure), though some small portion of it will be gaseous in a closed container.
B) CH Methylidyne radical is a gas
It is not a stable compound because carbon has four valence electrons and only one of those is kept occupied by the hydrogen atom.
If this is supposed to be CH₄ which is methane, then also a gas at STP
C) C₂H₅OH is ethanol which is mostly a liquid at STP, though some small portion of it will be gaseous in a closed container.
D) H₂O is water and will be mostly liquid at STP, though some small portion of it will be gaseous in a closed container.
CH₄ methane is the substance that is a gas a room temperature and atmospheric pressure, therefor the correct answer is option B.
What is the matter?Anything which has mass and occupies space is known as matter, mainly there are four states of matter solid liquid gas, and plasma.
These different states of matter have different characteristics according to which they vary their volume and shape.
Hg is liquid at room temperature
CH₄ methane is gas at room temperature
C2H5OH is liquid at room temperature
H20 is liquid at room temperature
CH₄ methane is the substance that is a gas a room temperature and atmospheric pressure, therefor the correct answer is option B.
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Your question seems incomplete the complete question should be ,
Which substance is a gas at room temperature and atmospheric pressure?
A. Hg
B. CH₄
C. C2H5OH
D. H20
A soccer player is 15 m from her opponent's goal. she kicks the ball hard; after 0.50s, it flies past a defender who stands 5m away, and continues toward the goal. How much time does the goalie have to move into position to block the kick from the moment the ball leaves the kickers foot?
Answer:
Explanation:
ASSUMING the defender at 5 m is NOT the goalie.
the ball horizontal velocity is 5 m/0.5 s = 10 m/s
The goalie, presumably at the goal line, has 15 m / 10 m/s = 1.5 s to react and move to the ball position.
Must be little league soccer as 10 m/s is a rather wimpy soccer ball speed.
Which of the following must an engineer take into account when designing a roller coaster?
A.the mass of the roller coaster
B. The rates at which the roller coaster will change directions
C. the total mass of the people that will ride the roller coaster
D. the acceleration of the roller coaster due to gravity
Answer:
The correct answer would be A
The amount of heat rejected by a heat pump to the high temperature reservoir will always be greater than the amount of heat absorbed from the low temperature reservoir.
a. True
b. False
The amount of heat rejected by a heat pump to the high-temperature reservoir will always be greater than the amount of heat absorbed from the low-temperature reservoir. The statement is true.
What is a heat pump?A heat pump is a device that uses a refrigeration cycle to transfer thermal energy from the outside to heat a building. Many heat pumps can also be used to cool a building by removing heat from the enclosed space and rejecting it outside.
Given the statement, the amount of heat rejected by a heat pump to the high-temperature reservoir will always be greater than the amount of heat absorbed from the low-temperature reservoir is true.
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-2 5/8 is bigger than -5/12
Answer:
hey...................................
2. Justin raees his Chevy S-10 down the highway for 30 seconds and travels 2560
meters. What was his average speed?
1 km = 1000 meters
2,560 meters / 1000 = 2.56 km
30 seconds is 1/2 minute
2.56 km x 2 = 5.12 km per minute
1 hour = 60 minutes
5.12 x 60 = 307.2 km per hour
Answer: 307.2 km per hour
A car increases velocity from 25 m/s to 50 m/s in 5 seconds. What is the acceleration of the car?
Answer:
the acceleration of the car is 5m/s2
poopybutt pickle juice
Answer:
poopybutt pickle juice????? baa?
Explanation:
A projectile is launched with an initial speed of 15.5 m/s at an angle of 78 degrees above the horizontal,
What are the x and y components of the initial velocity?
Answer:
Explanation:
The formula for the x-components of the velocity vector is
[tex]V_x=Vcos\theta[/tex] and for the y-components it is
[tex]V_y=Vsin\theta[/tex] where V in both of those formulas is the magnitude of the velocity.
For the x-component, taking into consideration significant digits:
[tex]V_x=15.5cos(78)\\V_x=3.2\frac{m}{s}[/tex]
For the y-component, taking into consideration significant digits:
[tex]V_y=15.5sin(78)\\V_y=15\frac{m}{s}[/tex]
