Explanation:
A simple machine has efficiency 90℅, it means that 90% of the applied force is used in doing useful work and 10% is wasted due to overcoming friction.
Which of the following can be excluded when evaluating the reliability of a source? (1 point)
O accuracy of data
O timeliness of information
O purpose of the author
O length of content
D. Length of content.
Reliable sources need to be accurate, they need to make sense at the time they were created and the author needs to not be biased with their writing. It does not matter how long the content is as long as it is reliable.
What is the displacement of a car traveling 14 km North on I985 then 20 km South on I985?
Displacement = (14-20) Km = -6 Km
The displacement of a car is -6 Km South
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.
The following are dimensions of various physical parameters that will be discussed later on in the text. Here [L], [T], and [M] denote, respectively, dimensions of length, time, and mass.
Dimension Dimension
Distance (x) [L] Acceleration (a) [L]/[T]2
Time (t) [T] Force (F) [M][L]/[T]2
Mass (m) [M] Energy (E) [M][L]2/[T]2
Speed (v) [L]/[T]
Which of the following equations are dimensionally correct?
a. F = ma
b. x = 2 at2
c. E = 1/2 max
d. E = max
e. F = ?Fx/m
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
learn more about dimentional analysis here: https://brainly.com/question/15631494
Bella makes the 2.5m distance to her food bowl in 9.1 seconds. What is her average velocity?
Average Velocity=Total Distance/Total Time
[tex]\\ \sf\longmapsto \dfrac{2.5}{9.1}[/tex]
[tex]\\ \sf\longmapsto 0.3m/s[/tex]
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
What phase of matter has the highest energy?
Answer:
plasma is the state with the highest energy level.
You have three flowers. You give
each a different amount of
water. What is one of the
possible controlled variables?
Answer:
flowers
Explanation:
flowers cannot change
what is an adam and a moreculw and a half note ???
.
BONUS: Usain Bolt speeds up from 0 m/s to 22 m/s in
55 seconds. What is his acceleration in meters per
minute (Round answer to nearest whole number)?
Answer:
0.4 meters per second I believe
explain 3points to be taken into consideration while measuring the length of a body
Answer:
Y T and v
Explanation:
A wheel of mass 4kg is pulled up a plane inclined at 30° to the horizontal by a force of 45N applied to the axle and parallel to the plane. If the wheel has a radius of 0.5m and the moment of inertia 0.5kgm?, calculate the translational velocity acquired after travelling 12m up the plane, assuming the wheel is initially at rest (6 marks)
Answer:
v = 10 m/s
Explanation:
Let's assume the wheel does not slip as it accelerates.
Energy theory is more straightforward than kinematics in my opinion.
Work done on the wheel
W = Fd = 45(12) = 540 J
Some is converted to potential energy
PE = mgh = 4(9.8)12sin30 = 235.2 J
As there is no friction mentioned, the remainder is kinetic energy
KE = 540 - 235.2 = 304.8 J
KE = ½mv² + ½Iω²
ω = v/R
KE = ½mv² + ½I(v/R)² = ½(m + I/R²)v²
v = √(2KE / (m + I/R²))
v = √(2(304.8) / (4 + 0.5/0.5²)) = √101.6
v = 10.07968...
hằng số phổ biến chất khí
Answer:
please in english......................................
Explanation:
What is the kinetic energy of a 0.5 kg soccer ball that is traveling at a
velocity of 3 m/s?
What’s the answer
Answer:
kinetic energy = 1/2mv²
k.E =1/2 X 0.5 X 3²
k.e = 9/4
K.E = 2.25j
Any two importance of measurement
Answer:
to sell and to buy
Explanation:
measurement is a comparison between unknown quantity with a known quantity
why do we observe winds blowing towards the equator
Answer:
The cooler air from region of up to 30degree latitude belt on both sides of the equator ,rushes toward the equator ,to take the place of warm rising air. This makes the wind to blow from north and south direction toward equators
2. Determine the units of the quantity described by each of the following
combinations of units:
a. kg (m/s) (1/s)
b. (kg/s) (m/s)
c. (kg/s) (m/s)
d. (kg/s) (m/s)
We have that the unit of the quantities are described
a.kg (m/s) (1/s)=Newton
b. (kg/s) (m/s^2)=Newton
c. (kg/s) (m/s)^2=Newton
d. (kg/s) (m/s)=Newton
From the question we are give the units
a.kg (m/s) (1/s)
b. (kg/s) (m/s^2)
c. (kg/s) (m/s)^2
d. (kg/s) (m/s)
a)
Generally
kg (m/s) (1/s) is Represented as Newton
Where Newton is the unit Force and Weight
b)
Generally
(kg/s) (m/s) is the unit representation of Newton
Therefore
Newton
c)
kg/s) (m/s) is the unit representation of Newton
Therefore
Newton
d)
Generally
(kg/s) (m/s) is the unit representation of Newton
Therefore
Newton
For more information on this visit
brainly.com/question/11800127
these questions !plz !! i need help!!!
(6) Wagon B is at rest so it has no momentum at the start. If v is the velocity of the wagons locked together, then
(140 kg) (15 m/s) = (140 kg + 200 kg) v
==> v ≈ 6.2 m/s
(7) False. If you double the time it takes to perform the same amount of work, then you halve the power output:
E / (2t ) = 1/2 × E/t = 1/2 P
I NEED THE ANSWER TO PASS SO I CAN GET MY PHONE BACK HELPPPPPPPPPPPPPP
Answer:
it would be c.
Explanation:
starts at zero and isn't a straight shot up
An object is launched at a 60 degree angle with an initial velocity of 100
m/s. What is the objects height? How long is the object in the air? What is
the objects's range (distance)? *
PLS HELP QUICK LOL
Answer:
Explanation:
The first question asks for the object's height. That is a y-dimension thing so we will use the one-dimensional formula:
[tex]v^2=v_0^2+2a[/tex]Δx and we are looking for delta x, which is the displacement of the object (here, the height since displacement in the y-dimension is height). Before we do that, though, we need to know the initial upwards velocity, which is found in:
[tex]v_{0y}=100sin(60)\\v_{0y}=90\frac{m}{s}[/tex]
And we also have to know from previous physics experience that the final velocity of an object at its max height is 0. Filling in:
[tex]0=(90)^2+2(-9.8)[/tex]Δx
[tex]0=8000-20[/tex]Δx and
-8000 = -20Δx so
Δx = 400 m
Now for the time it was in the air...we will use the simple equation
[tex]v=v_0+at\\0=90-9.8t\\-90=-9.8t\\t=9[/tex]
So the object is in the air for 9 seconds. Now we go to the other dimension, the x-dimension, to find out how far it goes horizontally. We will use the equation:
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] but first we have to find the horizontal velocity, which is NOT the same as the upwards velocity.
[tex]v_{0x}=100cos(60)\\v_{0x}=50\frac{m}{s}[/tex]
And another thing we need to know prior to solving problems like this is that the acceleration in the x-dimension is ALWAYS 0. Filling in the equation:
Δx = [tex]50(9)+\frac{1}{2}(0)(9)^2[/tex]
Δx = 500 m
In order to have a good hypothesis, which of the following are needed:
Answer:
There must be a possibility to prove that the hypothesis is true. There must be a possibility to prove that the hypothesis is false. The results of the hypothesis must be reproducible.
Explanation:
Make sure your hypothesis is "testable." To prove or disprove your hypothesis, you need to be able to do an experiment and take measurements or make observations to see how two things (your variables) are related. You should also be able to repeat your experiment over and over again, if necessary
6. A journalist is testing the acceleration of a new car. He measures the final velocity of the car to be 15 m/s. If the
car was initially stopped 10 s before the journalist made her measurement, what is the car's acceleration?
Answer:
1.5 m/s^2
Explanation:
Don't rlly understand the question, but I'll just take it as the initial velocity is 0
a = 15 - 0
- - - - - -
10
= 1.5 m/s^2
what’s the correct answer
According to 1st equation of motion :
[tex]\boxed{ \boxed{v = u + at}}[/tex]
where,
v = final velocityu = initial velocity a = acceleration t = timelet's solve for t
[tex] \hookrightarrow \: 17.63 = 0 + 2.13t[/tex]
[tex] \hookrightarrow \: t = \dfrac{17.63}{2.13} [/tex]
[tex] \hookrightarrow \: t = 8.276 \approx 8.28\: \: sec[/tex]
What is difference between simple microscope and compound microscope
Answer:
simple microscope - a codenser lens is not required I simple microscopes .
compound microscope- the condenser lens is embedded in compound microscopes for adjusting the intensity of the light to magnify the object.
Explanation:
hope this helps you
mrk me brainiliest
A man walks his dog on a very straight path in a park. He can walk back and forth as slow or fast as he wants to, but he has to stay on the path. Which of the following statements is correct for an arbitrary time interval?
a. His average speed can be greater than the magnitude of his average velocity.
b. His average speed can be less than the magnitude of his average velocity.
c. Since he is walking along a straight path, his average acceleration must be zero.
d. His average velocity must be zero.
Answer:
a. His average speed can be greater than the magnitude of his average velocity.
Explanation:
As speed is distance traveled over time traveled, this is always greater than zero if he has moved at all.
velocity is displacement over time traveled. As the man is allowed to return to the point of origin, his velocity at some point might be zero while his speed is positive.
what is kinematics ???
what is it concerned with ??
Kinematics deals with the motion and time
It is concerned with motion
[tex] \huge \boxed{\mathfrak{Question} \downarrow}[/tex]
What's kinematics? What is it concerned with?[tex] \huge \boxed{\mathfrak{Answer} \downarrow}[/tex]
Kinematics is a branch of mechanical physics that deals with motion. It includes all types of motion & all ways of showing motion (like, through graphs, moving objects & so on). In short kinematics is the => geometry of motion.A car is accelerating at 6 m/s2. How long would it take the car to go 12 m/s faster?
Answer:
2 seconds
Explanation:
Each second, it increases its speed by 6 m/s, so it will take 2 seconds for the speed to increase by 12 m/s.
A train accelerates from rest and covers a distance of 600m in 20s. What is the train's speed at the end of 20s? What is the final velocity of the train after 20s?
Answer:
v = 60 m/s
final velocity after 20 seconds depends on how long it continues to accelerate after 20 seconds. Also we do not know the direction to complete the velocity requirements of a scalar value and direction component.
Explanation:
If we assume that the acceleration is constant
d = ½at² = ½(Δv/t)t² = ½Δvt = ½(v - 0)t = ½vt
v = 2d/t
v = 2(600)/20 = 60m/s
Convert the following in to SI units without changing its values
a. 4000 g
b. 2.4 km
hi <3
i believe i explained this answer properly in my last answer but it would be 4kg and 2400m as these are the SI units for these values.
hope this helps :)
hi :D
i believe i explained this answer properly in my last answer but it would be 4kg and 2400m as these are the SI units for these values.
hope this helps :)
If an object is moving with a constant velocity then according to Newton's first law:
A- it will continue with this velocity only if a net external unbalanced force acts.
B- it will change its velocity if a net unbalanced external force is applied.
С- it will continue with its velocity as external unbalanced force acts.
D- it will continue with its velocity as friction only acts if an external unbalanced force is applied.
