2. A uniform rod of weight 5N and length 1m is pivoted at a point 20cm from one of its ends. A weight is hung from the other end so that the rod balances horizontally. What is the value of the weight?
Answer:
The weight is 7.5 N
Explanation:
Since the rod is uniform, its weight applies downwards at its middle (i.e 50 cm mark). The diagram attached to this answer shows the appropriate sketch.
Applying the principle of moment to the question, let the weight by represented by W.
Total clockwise moment = Total counterclockwise moment
[tex]F_{1}[/tex] x [tex]d_{1}[/tex] = [tex]F_{2}[/tex] x [tex]d_{2}[/tex]
5 x 0.3 = W x 0.2
1.5 = 0.2 W
W = [tex]\frac{1.5}{0.2}[/tex]
= 7.5 N
The value of the weight is 7.5 N.
Which energy source contributes least to global warming?
A. Coal
B. Natural gas
C. Solar
D. Petroleum
Solar energy source contributes least to global warming. Hence option C is correct.
What is renewable and non renewable energy sources ?Renewable energy is a energy from a source that is not exhausted or depleted when used. Solar energy or wind energy are examples of the renewable energy source. as wind and solar power is abundantly present everywhere in the environment, it can not be exhausted after its over use.
Non-renewable energy comes from sources that will be exhausted or will not be replenished after its use. Fossil fuels: coal, petroleum, and natural gas are the examples of the non renewable energy sources . Coal is the main element in fossil fuels.
Solar energy is abundantly available in the entire solar system. It is renewable energy source, it has no bad effect on the environment and global warming.
Hence option C is correct.
To know more about solar energy :
https://brainly.com/question/9704099
#SPJ7.
Margaret Mary, Doug , and Kako are at a local amusement park. They see an attraction called the Giant Slide, which is simply a very long and high inclined plane. Visitors at the amusement park climb a long flight of stairs to the top of the 27inclined plane and are given canvas sacks. They sit on the sacks and slide down the plane 70m long. At the time when the three friends walked past the slide, a 135-kg man and a 20-kg boy are each at the top preparing to slide down. "I wonder how much less time it will take the man to slide down than it will take the boy," said Margaret Mary. "I think the boy will take less time," said Doug. "You're both wrong,"said Kako. "They will reach the bottom at the same time."
The question is incomplete. The compete question is :
Margaret Mary, Doug , and Kako are at a local amusement park. They see an attraction called the Giant Slide, which is simply a very long and high inclined plane. Visitors at the amusement park climb a long flight of stairs to the top of the 27inclined plane and are given canvas sacks. They sit on the sacks and slide down the plane 70m long. At the time when the three friends walked past the slide, a 135-kg man and a 20-kg boy are each at the top preparing to slide down. "I wonder how much less time it will take the man to slide down than it will take the boy," said Margaret Mary. "I think the boy will take less time," said Doug. "You're both wrong,"said Kako. "They will reach the bottom at the same time."
If the man and the boy do not take the same amount of time to reach the bottom of the slide, calculate how many seconds of difference there will between the two times.
Solution :
From body sliding down an incline plane, the acceleration is given by, [tex]$a = g \sin \theta$[/tex]
Since the body slides from rest, the initial velocity is, u = 0
Now the equation of motion, we have
v= u + at
or v = 0 +at
or v = at
or [tex]$t=\frac{v}{a}$[/tex] ............(1)
again we have, [tex]$v^2 -u^2 =2as $[/tex]
or [tex]$v = \sqrt{2s g \sin \theta} $[/tex]
Then from equation (1), we have
[tex]$t=\frac{\sqrt{2sg \sin \theta}}{g \sin \theta}$[/tex]
Thus this means that the time of sliding down an inclined plane does not depend on the mass of the body that slides.
Therefore, Kako is correct.
Since the time taken to slide an inclined plane is same for both the man and the boy, there is no difference between their time of sliding.
When blue light (450 nm) is shone on a particular metal surface, electrons are ejected with a kinetic energy of 2.5 x 10-20 J. Calculate the work function for this metal.
Answer:
the work function of the metal is 4.167 x 10⁻¹⁹ J .
Explanation:
Given;
wavelength of the incident light, λ = 450 nm = 450 x 10⁻⁹ m
kinetic energy, K.E = 2.5 x 10⁻²⁰ J
The energy of the incident light is calculated as;
[tex]E = hf = \frac{h c}{\lambda} \\\\where;\\\\c \ is \ speed \ of \ light = 3 \times 10^8 \ m/s\\\\ h \ is \ Planck's constant = 6.626 \times 10^{-34} Js \\\\E = \frac{(6.626 \times 10^{-34})(3\times 10^8)}{450 \times 10^{-9}} \\\\E = 4.417 \times 10^{-19} \ J[/tex]
Apply Einstein photoelectric equation to determine the work function of the metal;
E = W + K.E
where;
W is the work function of the metal
W = E - K.E
W = 4.417 x 10⁻¹⁹ J - 2.5 x 10⁻²⁰ J
W = 44.17 x 10⁻²⁰ J - 2.5 x 10⁻²⁰ J
W = 41.67 x 10⁻²⁰ J
W = 4.167 x 10⁻¹⁹ J
Therefore, the work function of the metal is 4.167 x 10⁻¹⁹ J .
The work function of the photon is 4.167*10^19J
The energy of this photon can be calculated as
E = hc/λ
Data given;
λ = 450nm = 450*10^-9mh = 6.626*10^-34JSK.E = 2.5*10^-20Jc = 3.0*10^8m/sEnergy of the Photonsubstituting the values into the equation;
[tex]E = hc / y\\E = \frac{6.626*10^-^3^4*3.0*10^8}{450*10^-^9} \\E = 4.42*10^-^1^9J[/tex]
Work FunctionThe work function of the photon can be calculated as;
E = K.E + Ф
4.42*10^-19 = 2.5*10^-20 + Ф
Ф = [tex]4.42*10^-^1^9 - 2.5*10^-^2^0=4.167*10^-^1^9J[/tex]
The work function of the photon is 4.167*10^-19 J
Learn more on work function of a photon here;
https://brainly.com/question/11683155
Derive Isothermal process through ideal gas.(anyone plzz!!)
Answer:
Hey, bro here is the explanation....
Explanation:
Hope it helps...
A wave has frequency of 50 Hz and a wavelength of 10 m. What is the speed of the wave? Group of answer choices
Explanation:
hehshehebdbajahwwdszsjshshs shsbw
A boat traveling across a river has a resultant velocity of 10 km/h and travels 34 degrees with respect to the shore. A) What is the boats velocity in m/s?
B) What is the velocity of the river in m/s?
Answer:
a) 1.55 m/s
b) 2.3 m/s
Explanation:
We know that the boat travels across the river, if we define the river as the x-axis, then the velocity of the boat is only on the y-axis.
Then we can write the velocity of the boat in still water as:
S = (0, B)
Now, when the boat is on the river, the velocity of the boat will be equal to the velocity of the boat in still water plus the velocity of the river.
The velocity of the river is:
v = (R, 0).
Then the velocity of the boat in that river is:
V' = (0, B) + (R, 0) = (R, B)
Now, we know that the velocity of the boat is 10km/h, and it travels at an angle of 34° with respect to the shore.
We can use the Pythagoreans theorem to write the components of this velocity as:
x-axis component = 10km/h*cos(34°) = 8.29 km/h
y-axis component = 10km/h*sin(34°) = 5.59 km/h
Then the velocity of the boat can be written in components as:
velocity = ( 8.29 km/h, 5.59 km/h)
And we knew that the velocity of the boat was written as (R, B)
Then we must have:
R = 8.29 km/h
B = 5.59 km/h
a) The speed of the boat in m/s:
We know that the speed of the boat is 5.59 km/h.
First, we know that:
1km = 1000m, then:
5.59 km/h = 5.59*(1000m)h = 5,590 m/h
And we know that:
1h = 3600s
Then we can write:
5,590 m/h = 5,590 m/(3600s) = 1.55 m/s
b) The speed of the river in m/s:
We know that the speed of the river is 8.29 km/h
Using the same reasoning as above, we can do the change of units as follows:
8.29 km/h = 8.29 (1000m)/(3600s) = 2.3 m/s
A construction worker pushes a wheelbarrow with a total mass of 50.0 kg. What is the acceleration of the wheelbarrow if the net force on it is 75N? For physical science
Answer:
1.5m/s²
Explanation:
Given parameters:
Mass of the wheelbarrow = 50kg
Net force applied = 75N
Unknown:
Acceleration of the barrow = ?
Solution:
From Newton's second law of motion, we know that:
Force = mass x acceleration
Now insert the parameters and find the acceleration
75 = 50 x acceleration
Acceleration = 1.5m/s²
A tomado was moving at a velocity of 10 miles/hour north five minutes later the tomado is moving at a rate of 25 miles/hour north. What was the tornado's acclaration?
Answer:
180.7km/hr²
Explanation:
Given parameters:
Initial velocity = 10miles/hr
Final velocity = 25miles/hr
Time taken = 5minutes
To hr
60min = 1hr
5min gives 0.083hr
Unknown:
Acceleration = ?
Solution:
To solve this problem,
Acceleration = [tex]\frac{v - u}{t}[/tex]
v is the final velocity
u is the initial velocity
Acceleration = [tex]\frac{25 - 10}{0.083}[/tex] = 180.7km/hr²
When the Sun is directly overhead, a
hawk dives toward the ground at a speed of
3.31 m/s.
If the direction of his motion is at an angle
of 35° below the horizontal, calculate the
speed of his shadow along the ground.
Answer in units of m/s.
Answer:
2.71 m/s
Explanation:
Apply the formula for cosine of an angle where;
The hypotenuse is the speed the hawk dives towards the ground : 3.31 m/s
The angle of direction of motion from the horizontal is : 35°
Speed of the shadow along the ground will be, A ;
Cosine 35° = A / 3.31
A= 3.31 cosine 35°
A= 2.71 m/s
Help Please! 5 questions for 25 points? seems fair? Thank you!
Answer:
1. where the skater turns and goes back in the opposite direction- point w
2. gravitational force of the object
3. point a
4. the bar representing sphere 4 should be twice as tall as the bar representing sphere 2
5. B; its mass is smaller (?)
yolo
Answer:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Explanation:
h m u i m he ll a b o r e d
Answer:
KITTEEENNSSSSS last one is what i got for critsmas KlikBot Hexagon Special Pack
Explanation:
Why do we charge a capacitor under a DC voltage source only?
An 69-kg jogger is heading due east at a speed of 1.6 m/s. A 63-kg jogger is heading 14 ° north of east at a speed of 1.5 m/s. Find (a) the magnitude and (b) the direction of the sum of the momenta of the two joggers. Describe the direction as an angle with respect to due east.
Answer:
[tex]P=203.3819375kg.m/s\\P\approx203.4kg.m/s[/tex]
[tex]\theta=6.4541\textdegree North East\\\theta\approx6.5\textdegree North East[/tex]
Explanation:
From the question we are told that
Mass of first jogger [tex]M=69kg[/tex]
Speed[tex]v_1=1.6m/s[/tex]
Direction [tex]d= East[/tex]
Mass of 2nd jogger [tex]M=63kg[/tex]
Speed [tex]v_2=1.5m/s[/tex]
Direction [tex]d= 14\textdegree north[/tex]
Generally equation for momentum along the the horizontal is mathematically given as
[tex]P_x=m_1v_1 +m_2v_2cos\theta[/tex]
[tex]P_x=(69)*(1.6) +(63)*(1.5)cos14[/tex]
[tex]P_x=202.0929461kg.m/s[/tex]
Generally equation for momentum along the the vertical is mathematically given as
[tex]P_y=m_2v_2cos\theta[/tex]
[tex]P_x=22.86161913kgm/s[/tex]
a)Generally the magnitude of momentum is mathematically given by
[tex]P=\sqrt{(P_x)^2+(P_y)^2}[/tex]
[tex]P=\sqrt{(202.0929461)^2+(22.86161913)^2}[/tex]
[tex]P=\sqrt{41364.21249}[/tex]
[tex]P=203.3819375kg.m/s[/tex]
[tex]P\approx203.4kg.m/s[/tex]
b) Generally the angle [tex]\theta[/tex] is mathematically given by
[tex]\theta=tan^-^1\frac{py}{px} \\[/tex]
[tex]\theta=tan^-^1\frac{22.86161913}{202.0929461}[/tex]
[tex]\theta=tan^-^1(0.1131242805)[/tex]
[tex]\theta=6.4541\textdegree North East[/tex]
2200 kg semi truck driving down the highway has lost control. The truck rolls across the median and into oncoming traffic. The truck collides with a 2000 kg car that is traveling north at 45 m/s. The two vehicles stick together creating a single wreck that travels south at 15 m/s. what was the initial speed and direction of the semi truck?
Answer:
The semi truck travels at an initial speed of 69.545 meters per second downwards.
Explanation:
In this exercise we see a case of an entirely inellastic collision between the semi truck and the car, which can be described by the following equation derived from Principle of Linear Momentum Conservation: (We assume that velocity oriented northwards is positive)
[tex]m_{S}\cdot v_{S}+m_{C}\cdot v_{C} = (m_{S}+m_{C})\cdot v[/tex] (1)
Where:
[tex]m_{S}[/tex], [tex]m_{C}[/tex] - Masses of the semi truck and the car, measured in kilograms.
[tex]v_{S}[/tex], [tex]v_{C}[/tex] - Initial velocities of the semi truck and the car, measured in meters per second.
[tex]v[/tex] - Final speed of the system after collision, measured in meters per second.
If we know that [tex]m_{S} = 2200\,kg[/tex], [tex]m_{C} = 2000\,kg[/tex], [tex]v_{C} = 45\,\frac{m}{s}[/tex] and [tex]v = -15\,\frac{m}{s}[/tex], then the initial velocity of the semi truck is:
[tex]m_{S}\cdot v_{S} = (m_{S}+m_{C})\cdot v -m_{C}\cdot v_{C}[/tex]
[tex]v_{S} = \frac{(m_{S}+m_{C})\cdot v - m_{C}\cdot v_{C}}{m_{S}}[/tex]
[tex]v_{S} = \left(1+\frac{m_{C}}{m_{S}} \right)\cdot v - \frac{m_{C}}{m_{S}} \cdot v_{C}[/tex]
[tex]v_{S} = v +\frac{m_{C}}{m_{S}}\cdot (v-v_{C})[/tex]
[tex]v_{S} = -15\,\frac{m}{s}+\left(\frac{2000\,kg}{2200\,kg} \right) \cdot \left(-15\,\frac{m}{s}-45\,\frac{m}{s} \right)[/tex]
[tex]v_{S} = -69.545\,\frac{m}{s}[/tex]
The semi truck travels at an initial speed of 69.545 meters per second downwards.
A car of mass 1000 kg is travelling at 10 m/s. What is its kinetic energy?
Answer:
50,000
Explanation:
kinetic energy=1\2×mv^2
=1\2×1000kg×10×10
=50000
Henry designs an experiment to find out why plants without flowers tend to be wind-pollinated and not animal-pollinated. He takes samples from a variety of plants and studies them in the field. He finds that the evidence supports his hypothesis. Which of these was the hypothesis Henry was testing? Choose the correct answer. Nonflowering plants make less pollen than flowering plants. Nonflowering plants lack the structures to attract animal pollinators. Nonflowering plants grow close to the ground and capture fewer pollinators. Nonflowering plants grow close to the ground because they have no pollen grains.
Answer:
option 2
Explanation:
you are very welcom
The image shows landforms in Monument Valley, Utah.
Which correctly lists the three features shown in the photo?
folds, strike-slip faults, and anticlines
anticlines, synclines, and folds
synclines, normal faults, and strike-slip faults
normal faults, folds, and anticlines
The correctly lists the three features shown in the photo is folds, strike-slip faults, and anticlines.
What is the difference between folds and failures?Modern folds are those that emerged recently (on the scale of geological periods), that is, in the Tertiary Period (between 65 million and 2.5 million years ago). Faults are geological structures that originate from vertical (top-down) or inclined internal forces.
The transcurrent fault – also called horizontal fault – occurs when there is displacement in the horizontal plane between the two blocks, being more common in zones where two tectonic plates meet, when these also move horizontally.
See more about transcurrent fault at brainly.com/question/2387953
#SPJ2
Answer: folds, strike-slip faults, and anticlines. (A)
Explanation: Got it right on my exam on Edge.
You blow up a balloon but don't tie it. When you let it go, it flies around the room.
Which of Newton's Laws does the scenario describe?
1st Law
2nd Law
3rd Law
Answer:
3rd law beacuse there a flies
How high did a worker lift a 25 kg bag of sand if it now has 2940 of gravitational potential energy
Answer:
12 m
Explanation:
From the question given above, the following data were obtained:
Mass (m) of bag = 25 kg
Potential energy (PE) = 2940 J
Height (h) =?
Objects carried to a particular height will always experience an acceleration due to gravity of 9.8 m/s².
With the above in mind, we can obtain the height to which the load is lifted to as shown below:
Mass (m) of bag = 25 kg
Potential energy (PE) = 2940 J
Acceleration due to gravity (g) = 9.8 m/s².
Height (h) =?
PE = mgh
2940 = 25 × 9.8 × h
2940 = 245 × h
Divide both side by 245
h = 2940 / 245
h = 12 m
Therefore, the worker lifts the load to a height of 12 m.
Helium ballon containing 5m3 of Gad at a pressure of 30pka is released. If the temperature is constant calculate the volume the balloon would have when the pressure inside the ballon has fallen to 5kpa answer in metres cubed
Answer:
30m³
Explanation:
Calculation for the volume the balloon would have
First step is to calculate the Constant
Constant=30pka*5m³
Constant=150m³
Now let calculate the Volume using this formula
Balloon Volume=Constant/ Pressure
Let plug in the formula
Balloon Volume=150m³/5kpa
Balloon Volume=30m³
Therefore the volume that the balloon would have when the pressure inside the ballon has fallen to 5kpa is 30m³
If a 1000 kg car is traveling at 3
meters per second, what is its
kinetic energy?
A wave that can travel through empty space?
A. electromagnetic wave
B. mechanical wave
C. compressional wave
D. transverse wave
Answer: B. Mechanical Waves
Explanation:
[04.04] Which best describes the current atomic theory?
What net force is required to accelerate a car at a rate of 3m/s^2 if the car has a mass of 2,000 kg?
Answer:
6000 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 2000 × 3
We have the final answer as
6000 NHope this helps you
A ball is thrown with 50J of kinetic energy, it hits a target which moves with 30J of kinetic energy, how much energy goes to the thermal store of the surroundings?
Answer:
The energy that will go will for thermal store of the surroundings is 20 J.
Explanation:
Given;
kinetic of the thrown ball, K.E₁ = 50 J
kinetic energy used to move the target, K.E₂ = 30 J
The excess energy that will go will for thermal store of the surroundings;
ΔK.E = K.E₁ - K.E₂
ΔK.E = 50J - 30J
ΔK.E = 20 J
Therefore, the energy that will go will for thermal store of the surroundings is 20 J.
Metals are good conductors of heat because .
Answer:
They have the highest melting point so that mean that the temperature and the are a conductive to electricity.
Explanation:
A professional golfer walks at an at an average rate of 4.20 meters per second on the golf course. The amount of time required for her to walk from the tee to the green 622 meters away is
Answer:
T try d add b CD c
Explanation:
Cdgffd
How are CD's recorded?
Using digital technology
using analog technology
Answer:
its digital technology
Fig. 2.1 shows a train
Fig. 2.1
The total mass of the train and its passengers is 750000kg. The train is travelling at a speed of 84m/s.
The driver applies the brakes and the train takes 80s to slow down to a speed of 42m/s.
(a) Calculate the impulse applied to the train as it slows down,
impulse =
[3]
(b) Calculate the average resultant force applied to the train as it slows down,
force =
(2)
Answer:
[tex]\mathrm{(a)\:}32,000,000\:\mathrm{Ns},\\\mathrm{(b)\:}390,000\:\mathrm{N}[/tex]
Explanation:
The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by [tex]p=mv[/tex]. Since mass is constant, the train's change in momentum is:
[tex]\Delta p=m\Delta v=750,000\cdot42=31,500,000=\fbox{$32,000,000\:\mathrm{Ns}$}[/tex](two significant figures).
Impulse is also given as [tex]\Delta p = F\Delta t[/tex], where [tex]F[/tex] is the average force applied and [tex]\Delta t[/tex] is change in time. Since [tex]t[/tex] is given as [tex]80\mathrm{s}[/tex], we have the following equation:
[tex]F\Delta t=\Delta p\\\\F=\frac{\Delta p}{\Delta t},\\\\F=\frac{31,500,000}{80},\\\\F=393,750=\fbox{$390,000\:\mathrm{N}$}[/tex](two significant figures).