Answer:
η = 0.667 = 66.7%
Explanation:
The efficiency of the man can be given by the following formula:
η = output/input
where,
η = efficiency of man = ?
output = potential energy gain of the box = Wh
input = work done by man = Fd
Therefore,
[tex]\eta = \frac{Wh}{Fd}[/tex]
where,
W = weight of box = 200 N
h = height gained by box = 1 m
F = force exerted by man = 60 N
d = length of ramp = 5 m
Therefore,
[tex]\eta = \frac{(200\ N)(1\ m)}{(60\ N)(5\ m)}[/tex]
η = 0.667 = 66.7%
What is the relationship between the density of the equipotential lines, the density of the electric field lines and the strength of the electric field?
Answer:
I dont. understand the question, maybe insert the picture?
g A ball is tossed straight up from the surface of a small, spherical asteroid with no atmosphere. The ball rises to a height equal to the asteroid's radius and then falls straight down toward the surface of the asteroid. What forces, if any, act on the ball while it is on the way up
Answer:
Only a decreasing gravitational force that acts downward
Explanation:
The gravitational force is the gravitational pull which attract a mass of smaller size by the mass of a bigger size. It is the force which attract two masses close to each other.
In the context, when a ball is tossed up from the surface of an asteroid that have no atmosphere, the ball rises up and then falls back to the surface of the asteroid. The ball falls back because the gravitational pull of the asteroid pulls back the ball to its surface. Thus a decreasing gravitational force acts on the ball in the downward direction while the ball is in its way up.
At 2:00, Alice was traveling in a car at 40 miles/hour. She then slows down, and at 4:00, she was traveling at 20 miles/hour.
What was Alice’s average acceleration between 2:00 and 4:00?
Show your complete calculation and state your answer with the correct units.
Answer:
-10miles/hr²
Explanation:
a = ∆v/∆t
Where:
a = acceleration (miles/hr²)
∆V = change in velocity (miles/hr)
t = time (hour)
The change in time is from 2:00 - 4:00 ∆t = 2 hours.
The distance covered is as follows: 20miles/hour - 40 miles/hr
∆v = -20miles/hr
Using a = ∆v/∆t
a = -20/2
a = -10miles/hr²
the organelle involved in cell secretion is
Answer:
Golgi apparatus (bodies).
Explanation:
A cell can be defined as the fundamental or basic functional, structural and smallest unit of life for all living organisms. Some living organisms are unicellular while others are multicellular in nature.
Generally, cells have the ability to independently replicate themselves. In a cell, the "workers" that perform various functions or tasks for the survival of the living organism are referred to as organelles. Some examples of cell organelles found in all living organisms such as trees, birds, and bacteria include; nucleus, cytoplasm, cell membrane, golgi apparatus, mitochondria, lysosomes, ribosomes, chromosomes, endoplasmic reticulum, vesicles, etc.
Golgi apparatus is also referred to as Golgi bodies and it functions as a packaging unit in living organisms, especially eukaryotic cells because it prepares protein and lipid molecules for export by chemically tagging them.
Hence, the Golgi apparatus (bodies) is an organelle involved in cell secretion through the transportation (export) of proteins and lipids out of a cell.
If a spider can travel 3.5 meters in 25 minutes, how fast can they go?
What does Coulomb's law applies to:
1. Like charges and unlike charges
2. Charge motion
3. gravitational fields
4. moving objects
A disk-shaped platform has a known rotational inertia ID. The platform is mounted on a fixed axle and rotates in a horizontal plane with an initial angular velocity of ÏD in the counterclockwise direction as shown. After an unknown time interval, the disk comes to rest. A single point on the disk revolves around the center axle hundreds of times before the disk comes to rest. Frictional forces are considered to be constant.
In a different experiment, the original disk is replaced with a disk for which frictional forces are considered to be negligible. The disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small sphere of clay is dropped onto the disk, and the sphere sticks to the disk.
Required:
Write down the claims which are correct about the angular momentum and the total kinetic energy of the disk-sphere system immediately before and immediately after the collision.
Answer:
Explanation:
The angular momentum of that same disk-sphere remains unchanged the very same way before and after the impact of the collision when the clay sphere adheres to the disk.
[tex]\mathbf{I_w}[/tex] = constant.
The overall value of such moment of inertia is now altered when the clay spherical sticks. Due to the inclusion of the clay sphere, the moment of inertia will essentially rise. As a result of this increase, the angular speed w decreases in value.
Recall that:
The Kinetic energy is given by:
[tex]\mathbf{K = \dfrac{1}{2} Iw^2} \\ \\\mathbf{K = \dfrac{1}{2} lw*w}[/tex]
where;
[tex]\mathbf{I_w}[/tex] is constant and w reduces;
As a result, just after the collision, the system's total kinetic energy decreases.
The total kinetic energy of the system decreases after the collision.
What is angular momentum?The angular momentum of any rotating body is defined as the product of the moment of inertia of the body and the angular velocity of the body.
Now from the question, we can see that the angular momentum of the body remains constant before and after the impact of the collision when the clay sphere adheres to the disk.
So angular momentum will be
[tex]Iw[/tex] = constant.
The overall value of such a moment of inertia is now changed when the clay spherical sticks. Due to the inclusion of the clay sphere, the moment of inertia will essentially rise. As a result of this increase, the angular speed w decreases in value.
The Kinetic energy is given by:
[tex]KE=\dfrac{1}{2} Iw^2[/tex]
[tex]KE= \dfrac{1}{2} Iw\times w[/tex]
Since the angular momentum [tex]Iw[/tex] is constant and w is reducing then ultimately the energy of the system is decreasing.
Thus the total kinetic energy of the system decreases after the collision.
To know more about Angular momentum follow
https://brainly.com/question/25677703
The cliff divers at Acapulco, Mexico, jump off a cliff m above the ocean. Ignoring air resistance, how fast are the divers going when they hit the water
Answer:
22.87 m/s
Explanation:
Since the value of the height at which the divers jump off the cliff is not given,
Assuming that the height of the cliff above the ocean at which the divers jump = 26.7 m
Then;
The speed of the divers when they hit the ocean water can be determined by using the formula:
[tex]v^2 = 2gh \\ \\ v= \sqrt{2gh} \\ \\ v = \sqrt{2 \times 9.8 \times (26.7)} \\ \\ v \simeq 22.87 \ m /s[/tex]
PLS HELP ME. A 0.0780 kg lemming runs off a 5.36m high cliff at 4.84 m/s what is it potential energy when it lands?
Answer:
p.e=0.078kg×1/2×5.36m
p.e=0.913j
Two cars travel in the same direction along a straight highway, one at a constant speed of 55 mi/h and the other at 60 mi/h.How far must the faster car travel before it has a 15-min lead on the slower car
Answer:
The distance traveled by the faster car when it is 15 mins ahead of the slower car is 165 miles.
Explanation:
Given;
speed of the faster car, v₁ = 60 mi/h
speed of the slower car, v₂ = 55 mi/h
Let the distance traveled by the faster car when it is 15 mins ahead of the slower car = x miles
[tex]\frac{x}{55} - \frac{x}{60} = \frac{15}{60}[/tex]
Note: divide 15 mins by 60 to convert to hours for consistency in the units.
[tex]\frac{x}{55} - \frac{x}{60} = \frac{15}{60}\\\\multiple \ through \ by \ 660\\\\12x - 11x = 165\\\\x = 165 \ miles[/tex]
Therefore, the distance traveled by the faster car when it is 15 mins ahead of the slower car is 165 miles.
Each of the four expansion models (recollapsing, critical, coasting, and accelerating) predict different ages for the universe, given the current expansion rate. Why is this
Answer:
This is because the age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
Explanation:
The age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
This is due to the fact that the expansion rate in the coasting model is constant and never changes. Because the cosmos is growing faster now than during the old days, recollapsing and critical models give shorter ages. According to the accelerating model, the universe is growing at a slower rate currently than in the past, implying an older age.
what happened in my room
Answer:
A GHOST CAME! Booooo!!!!!!Hah lol
____ is the study of things getting faster as they move.
A. Anatomy
B. Force
C. Physics
D. Dynamics
Answer: b force
Explanation:
yes because the world comin g up with more technique
A voltage of 75 V is placed across a 150 Ω resistor. What is the current through the resistor?
Answer:
0.5 A
Explanation:
Applying,
V = IR.................. Equation 1
Where V = Voltage, I = current, R = Resistance.
make I the subject of the equation
I = V/R............... Equation 2
From the question,
Given: V = 75 V, R = 150 Ω
Substitute these values into equation 2
I = 75/150
I = 0.5 A.
Hence the cuurent through the resistor is 0.5 A
state the two motion equations.
Answer:
Equations of motion relate the displacement of an object with its velocity, acceleration and time. s=vt where s is the displacement, v the (constant) speed and t the time over which the motion occurred. ...
Displacement with negative acceleration: s, equals, v, t, minus, one half, a, t, square...
Displacement with positive acceleration: s, equals, u, t, plus, one half, a, t, squared,s...
Velocity squared: v, squared, equals, u, squared, plus, 2, a, s,v2=u2+2as
Velocity: v, equals, u, plus, a, t,v=u+at
Keesha is looking at a beetle with a magnifying glass. She wants to see an upright, enlarged image at a distance of 25 cm. The focal length of the magnifying glass is +5.0 cm. Assume that Keesha's eye is close to the magnifying glass.
(a) What should be the distance between the magnifying glass and the beetle?
(b) What is the angular magnification?
Answer:
a) p = 4.167 cm, b) m = + 6
Explanation:
a) For this exercise we must use the equation of the constructor
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]
where f is the focal length, p and q are the distance to the object and the image, respectively
In this case the distance to the image q = 25 cm and the focal length is f = 5.0 cm
Since the object and its image are on the same side of the lens, the distance to the image by the sign convention must be negative.
[tex]\frac{1}{p } = \frac{1}{f} - \frac{1}{q}[/tex]
[tex]\frac{1}{p} = \frac{1}{5} - \frac{1}{-25}[/tex]
[tex]\frac{1}{ p}[/tex] = 024
p = 4.167 cm
b) angular magnification
m = h ’/ h = - q / p
m = - (-25) /4.167
m = + 6
the positive sign indicates that the image is straight and enlarged
Which statements are true of noble gases?
Check all that apply.
A. They are metalloids.
B. Their valence shells are full of electrons.
C. They are not very reactive.
D. All of the noble gases have at least two electron shielding layers.
Many adventures like to go rafting on the Colorado River through Grand Canyon National Park. There are many locations where the river becomes more narrow, both the distance between the canyon walls as well as the depth changes due to debris like boulders on the bottom of the river; this leads to changes in the water speed. In the park, the Colorado River has an average width of 100m and an average depth of 8m, and an average speed of 3 m/s. At the Lava Falls Rapids, the river has an average width of about 25m and an average depth of about 15m. What is the approximate speed of the water in this location
Answer:
6.4 m/s
Explanation:
Given that :
The average width of the Colorado river = 100 m
Average depth of the river is = 8 m
Therefore, area = [tex]$A_1= 100 \ m \times 8 \ m$[/tex]
Speed of the river, [tex]$v_1 = 3 \ m/s$[/tex]
After the lava falls on the river,
Width of the river becomes = 25 m
Depth of the river became = 15 m
Therefore, area = [tex]$A_2= 25 \ m \times 15 \ m$[/tex]
Now, since the volume flow rate of the Colorado river is same, then from the Continuity equation,
[tex]$Q_1=Q_2$[/tex]
[tex]$A_1v_1=A_2v_2$[/tex]
∴ [tex]$100 \times 8 \times3 = 25 \times 15 \times v_2$[/tex]
[tex]$v_2=\frac{100 \times 8 \times 3}{25 \times 15}$[/tex]
= 6.4 m/s
Therefore, the speed of the river in this location is 6.4 m/s
Iron is a solid phase of iron still unknown to science. The only difference between it and ordinary iron is that Iron forms a crystal with an fcc unit cell and a lattice constant . Calculate the density of Iron.
The question is incomplete. The complete question is :
Iron β is a solid phase of iron still unknown to science. The only difference between it and ordinary iron is that Iron β forms a crystal with an fcc unit cell and a lattice constant, a = 0.352 nm. Calculate the density of Iron β.
Solution :
The density is given by :
[tex]$\rho = \frac{ZM}{a^3N_0} \ \ g/cm^3$[/tex] ..................(i)
Here, Z = number of atoms in a unit cell
M = atomic mass
[tex]$N_0$[/tex] = Avogadro's number = [tex]$6.022 \times 10^{23}$[/tex]
a = edge length or the lattice constant
Now for FCC lattice, the number of atoms in a unit cell is 4.
So, Z = 4
Atomic mass of iron, M = 55.84 g/ mole
Given a = 0.352 nm = [tex]$3.52 \times 10^{-8}$[/tex] cm
From (i),
[tex]$\rho = \frac{ZM}{a^3N_0} $[/tex]
[tex]$\rho = \frac{4 \times 55.84}{(3.52 \times 10^{-8})^3 \times 6.022 \times 10^{23}} $[/tex]
[tex]$= 8.51 \ \ g \ cm ^{-3}$[/tex]
Therefore, the density of Iron β is [tex]$ 8.51 \ \ g \ cm ^{-3}$[/tex].
Which of the following is the best definition of a physical change?
A. A change in a substance where a new substance is formed
B. A change in a substance in which bonds are broken
C. A change in a substance with no new substances being formed
D. A change in a substance in which mass is conserved
Answer:
The answer is C. A change in a substance with no new substances being formed
Explanation:
I did the quiz.
The best definition of physical change is a change in a substance, with no new substances being formed. Hence, option C is correct.
What is a Physical Change?A chemical substance's form, not its chemical composition, can change due to physical changes. In most cases, compounds cannot be separated into chemical components or simpler compounds; instead, mixtures are separated into their constituent compounds through physical changes.
Whenever something changes physically but not chemically, we say that something has changed physically. This is in contrast to the idea of a chemical change, which occurs when a substance's composition changes or when one or more compounds join or fragment to generate new substances. In general, physical means can be employed to undo a physical alteration. For instance, by letting the water evaporate, salt that has been dissolved in it can be reclaimed.
Therefore, this concludes that option C is correct.
To know more about Physical change:
#SPJ2
PLEASE HELPPPPPP ME PLS PLS
Besides toxic pollution, the other types of pollution are sediment pollution, nutrient pollution, and bacterial pollution.
a. True
b. False
Answer:
a. True
Explanation:
Pollution can be defined as the physical degradation or contamination of the environment through an emission of harmful, poisonous and toxic chemical substances.
Aside from toxic pollution, the other types of pollution includes the following;
I. Sediment pollution.
II. Nutrient pollution.
III. Bacterial pollution.
Furthermore, particulate pollution is a form of pollution that is responsible for the degradation of the environment.
Particulate matter is also referred to as particle pollution or atmospheric aerosol particles and it can be defined as a complex microscopic mixture of liquid droplets and solid particles that are suspended in air. Other forms of particle pollution includes space debris and marine debris.
Some examples of particulate pollution are dusts, soot, dirt, smoke, etc.
Answer:a
Explanation:
the boiling point of F2 much lower than the boiling point of NH3
Answer:yeah it A
Explanation:
Charge q is a test charge used to measure the electric field created by a source charge Q. What happens to the magnitude of the electric force on these charges if q is doubled?
Answer:
The electric force will also double.
When the test charge q is double the change in magnitude of the electric force is that it also gets doubled.
What is the electric force due to charge?Electric force is defined as force between the chages which is directly proportional to the product of charges and inversely proportional to the square of the distance between them. The electric force is a vector quantity, It have magnitude as well as direction.
Electric force = k*Q*q/r²
The electric field is defined as the electric force per unit charge. The electric field is a vector quantity.
Electric field = Electric force / test charge
Electric field = k*Q/r²
Given that in question there is the test charge, q for electric field and the source charge Q when the test charge q will become 2q then electric force is,
Electric force = kQ(2q)/r²
So, the magnitude of the electric force is increased by twice when the test charge will become 2q.
To learn more about the electric force refer to the link
brainly.com/question/2526815
#SPJ2
3. Sally (45 kg) and Stan (90 kg) and arrive at Michigan Adventure and climb the stairs to ride the big
Shivering Timber coaster that is nearly 40 m tall and reaches speeds of 65 mi/hr.
a) Compare the potential energies of Sally and Stan as they wait in line at the top of the stairs.
Explain your reasoning.
A person carries a plank of wood 1.6 m long with one hand pushing down on it at one end with a force F1 and the other hand holding it up at 43 cm from the end of the plank with force F2. If the plank has a mass of 13.7 kg and its center of gravity is at the middle of the plank, what is the force F1
Answer: [tex]115.52\ N[/tex]
Explanation:
Given
Length of plank is 1.6 m
Force [tex]F_1[/tex] is applied on the left side of plank
Force [tex]F_2[/tex] is applied 43 cm from the left end O.
Mass of the plank is [tex]m=13.7\ kg[/tex]
for equilibrium
Net torque must be zero. Taking torque about left side of the plank
[tex]\Rightarrow mg\times 0.8-F_2\times 0.43=0\\\\\Rightarrow F_2=\dfrac{13.7\times 9.8\times 0.8}{0.43}\\\\\Rightarrow F_2=249.78\ N[/tex]
Net vertical force must be zero on the plank
[tex]\Rightarrow F_1+W-F_2=0\\\Rightarrow F_1=F_2-W\\\Rightarrow F_1=249.78-13.7\times 9.8\\\Rightarrow F_1=115.52\ N[/tex]
The human eye has two lenses.
O true
O False
Answer:
true its truedjjs sjsnsns
Andrea, a 61.5 kg sprinter, starts a race with an acceleration of 3.700 m/s2. If she accelerates at that rate for 12.00 m and then maintains that velocity for the remainder of a 100.00 m dash, what will her time (in s) be for the race
Answer:
The total time it will take her to complete the race is 13.17 s
Explanation:
Given;
mass of the sprinter, m = 61.5 kg
acceleration of the sprinter, a = 3.7 m/s²
first distance covered, d₁ = 12 m
Determine her velocity for the first 12 m;
v² = u² + 2as
v² = 0 + (2 x 3.7 x 12)
v² = 88.8
v = √88.8
v = 9.42 m/s
Determine her time for the first 12 m;
v = u + at
9.42 = 0 + 3.7t₁
9.42 = 3.7t₁
t₁ = 9.42 / 3.7
t₁ = 2.55 s
Determine the time it will take her to complete the last 100 m at a constant velocity of 9.42 m/s
s = vt₂ + ¹/₂at₂²
s = vt₂ + ¹/₂(0)t₂²
s = vt₂
100 = 9.42t₂
t₂ = 100 / 9.42
t₂ = 10.62 s
The total time it will take her to complete the race = 2.55 s + 10.62 s
= 13.17 s
Two identical particles each of mass M and charge Q are placed a certain distance apart. If they are in equilibrium
under mutual gravitational and electric force then calculate the order of Q/M in SI units.
Answer:
Q / m = 8.61 10⁻¹¹ C / kg
Explanation:
For this exercise we use the gravitational force of attraction
[tex]F_g = G \frac{m_1m_2}{r^2}[/tex]
the electric force
[tex]F_e = k \frac{q1q2}{r^2}[/tex]
indicate that the two forces are equal
G m₁ m₂ / r² = k q₁ q₂ / r²
they also say that the two masses are equal and the two charges are equal
G m² = k Q²
Q / m = [tex]\sqrt{\frac{G}{k} }[/tex]
we calculate
Q / m = [tex]\sqrt{\frac{6.67 \ 10^{-11} }{8.99 \ 10^9} }[/tex]
Q / m = [tex]\sqrt{ 0.7419 \ 10 ^{-20}}[/tex]
Q / m = 0.861 10⁻¹⁰
Q / m = 8.61 10⁻¹¹ C / kg
One coulomb represents how many electrons?
a. 1 electron
b. 100 electrons
C. 6.25 quintillion electrons
d. 6.25 million-million electrons
e, none of the above
Answer:
6.24 x 1018 electrons.
Explanation:
So I think C