Answer:
A
Explanation:
A horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension force F in the chain. What is the moment of the force F about the pivot P?
Answer:
Fscos63
Explanation:
Given that a horizontal pole is attached to the side of a building. There is a pivot P at the wall and a chain is connected from the end of the pole to a point higher up the wall. There is a tension force F in the chain. What is the moment of the force F about the pivot P?
Taking the moment from the pivot point P, that means the moment at point p = 0
Then, if we consider the weight mg of the pole, according to the principle of equilibrium : sum of the upward forces equal to the sum of the downward forces.
Therefore, mg = Fsinø ....... (1)
Also, taking moment at point P
Let the length of the pole = s
The length of the weight of the pole = 1/2 S
Fscosø = mgs/2
The distance s will cancel out
2Fcosø = mg ...... (3)
Substitute mg in equation 1 into equation 3
2fcosø = fsinø
F will cancel out
Tanø = 2
Ø = tan^-1(2)
Ø = 63.4 degree
The moment of force F about pivot point P will be
Moment = force × distance
Moment = Fcos63 × S
Moment = Fscos63
A box weighs 1300 N. When a horizontal force of 390 N has applied the box accelerates at 1.3 m/s2. What is the magnitude of the frictional force?
Answer:
Ffriction = 217.7[N]
Explanation:
First, we must find the mass of the box, we must remember that the weight is defined as the product of the mass by acceleration.
[tex]w=m*g[/tex]
where:
w = weight [N] (units of Newtons)
m = mass [kg]
g = gravity acceleration = 9.81 [m/s²]
[tex]1300=m*9.81\\m=132.51[kg][/tex]
Now we must use Newton's second law, which tells us that the sum of forces is equal to the product of mass by acceleration.
∑F = m*a
where:
∑F sum of forces
m = mass = 132.51[kg]
a = acceleration = 1.3[m/s²]
We must know that the forces that act are the horizontal force that moves the box and the friction force in the negative direction that acts against the movement.
Now replacing:
[tex]390-f_{friction}=132.51*1.3\\390-172.26=f_{friction}\\f_{friction}=217.7[N][/tex]
The radius of a planet is 2400 km, and the acceleration due to gravity at its surface is 3.6 m/s2.
What is the mass of the planet?
Answer:
[tex]3.1\cdot10^{23}\:\mathrm{kg}[/tex]
Explanation:
We can use Newton's Universal Law of Gravitation to solve this problem:
[tex]g_P=G\frac{m}{r^2}[/tex]., where [tex]g_P[/tex] is acceleration due to gravity at the planet's surface, [tex]G[/tex] is gravitational constant [tex]6.67\cdot 10^{-11}[/tex], [tex]m[/tex] is the mass of the planet, and [tex]r[/tex] is the radius of the planet.
Since acceleration due to gravity is given as [tex]m/s^2[/tex], our radius should be meters. Therefore, convert [tex]2400[/tex] kilometers to meters:
[tex]2400\:\mathrm{km}=2,400,000\:\mathrm{m}[/tex].
Now plugging in our values, we get:
[tex]3.6=6.67\cdot10^{-11}\frac{m}{(2,400,000)^2}[/tex],
Solving for [tex]m[/tex]:
[tex]m=\frac{2,400,000^2\cdot3.6}{6.67\cdot 10^{-11}},\\m=\fbox{$3.1\cdot10^{23}\:\mathrm{kg}$}[/tex].
Will mark brainliest Why are acoustic panels are used in concert halls
Answer:
what person above said is correct
Explanation:
The walls of the concert halls are used to control the acoustic. ... Rough surfaces can also be used to disperse sound in all directions – this might be used in concert halls to get rid of echoes that would distract from performances.
An acoustic panel is a sound-absorbing panel used to mitigate noise and reduce the reverberation and echo in a space. For both types, we can talk about different principles of good acoustics: absorption, diffusion, and attenuation. These are all linked to the acoustic performance of the panels.
brainliest?2) Ariel dropped a golf ball from her second story window. The ball starts from rest and hits the sidewalk 1.5 s later with a velocity of 14.7 m/s. Find the average acceleration of the golf ball.1.5x14.7 =22.05
Answer:
Acceleration = 9.8m/s²
Explanation:
Given the following data;
Initial velocity = 0m/s (since it's starting from rest).
Final velocity, v = 14.7m/s
Time, t = 1.5 seconds.
To find acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]Acceleration = \frac{v - u}{t}[/tex]
Substituting into the equation, we have;
[tex]Acceleration = \frac{14.7 - 0}{1.5}[/tex]
[tex]Acceleration = \frac{14.7}{1.5}[/tex]
Acceleration = 9.8m/s²
Therefore, the average acceleration of the golf ball is 9.8m/s².
A scientist uses different types of gasoline in the engines of three identical
cars. She measures how far the cars go before running out of gas. What is
the controlled variable in this experiment?
A. The type of gas the cars are given
B. The distance the cars go
C. The amount of gas the cars are given
D. The type of cars that are used
Answer:
the types of gas the car is given
Explanation:
All three cars are identical and have different gas in each car so she is trying to determine how each car will react with different gasoline.
please help will give brainlyest
An electromagnetic wave moves through electric and magnetic fields. What
is the relationship between the wave and the fields?
O A. The vibrations of the fields are in the same direction but
perpendicular to the motion of the wave.
B. The vibrations of the fields are at 90° angles to the direction of
motion of the wave.
C. The vibrations of the fields and wave motion are all parallel to
each other.
D. The vibrations of the fields and the wave motion are at 180°
angles to each other.
Answer:
B. The vibrations of the fields are at 90° angles to the direction of
motion of the wave.
Explanation:
Electromagnetic waves are waves that are produced by the vibration of the electric and magnetic fields.
Both fields are oriented perpendicularly to one another. This vibration produces the electromagnetic waves.
These waves are very unique in that they do not require any material medium for propagation.
There is a broad spectrum of electromagnetic waves with gamma rays being the most energetic and radio waves being the least energetic.
Answer: B is the correct answer
Explanation:
A plane flew at a speed of 600 km/hr for a distance of 1500 km,
How long did take to get to its destination
Explanation:
600 ÷ 60 = 10
1500 ÷ 10 = 150 minutes
I don't know how you should express the answer in:
So it's either 150 minutes or 2 hours and 30 minutes.
(This is kind of like mathematics, not physics)
which of the following is an example of thermal energy being transferred directly from one substance to another via conduction?
Answer:I think it’s D
Explanation:
Conduction needs direct touch to transfer
If Bert the Bat travels East at 200 meters in 10 seconds, what is his velocity?
Answer:
20m/s due east
Explanation:
Given parameters:
Displacement eastward = 200m
Time = 10s
Unknown:
Velocity = ?
Solution:
Velocity is the displacement divided by time;
Velocity = [tex]\frac{displacement}{time}[/tex]
Velocity = [tex]\frac{200}{10}[/tex] = 20m/s due east
What is Earth's primary source of radiant energy?
Answer:
the sun?
Explanation:
Answer:
the sun
Explanation:
.A water tank has dimensions
of 6m x 4m x 4m. Find the pressure exerted by
water at the base of dam when it is half
filled. ( Density of water - 1000 kg/ m2,
acceleration
due to to gravity is 9.8m/s2
Answer:
9800Nm⁻²
Explanation:
Given parameters:
Dimensions of the water tank = 6m x 4m x 4m
Density of water = 1000kgm⁻³
Gravity = 9.8m/s²
Unknown:
Pressure exerted by the water at the base of the dam = ?
Solution:
The pressure exerted by the water is given as:
Pressure = density of water x acceleration due to gravity x height of water
The height of the water here is half = 1m
Pressure = 1000 x 9.8 x 1 = 9800Nm⁻²
a car has a mass of 1200 kg. what would be its weight on earth?
Answer:
11772 N
Explanation:
[tex]\boxed{w = mg}[/tex]
w= weight
m= mass
g= acceleration due to gravity
The acceleration due to gravity on earth is 9.81m/s².
Substitute m= 1200 and g= 9.81 into the formula:
w= 1200(9.81)
w= 11772 N
What is the same about a particle as gas, liquid, or solid?
A. The speed at which the particles move.
B. The volume that the substance takes up.
C. The chemical composition.
D. The temperature of the substance.
The thing same about a particle as gas, liquid, or solid is its chemical composition.
What are states of matter?
Matter exists in three different states: solid, liquid, and gas. By examining the configuration of their particles, it is possible to understand why they have various qualities. Theoretically, at this temperature, particles move slowly and have the least amount of energy.
Phase refers to the material's actual state. To pay attention to is the word physical. Only physical means can change the state of matter. You can make a physical change if energy is added (by raising the temperature) or subtracted (by freezing things).
The chemical composition of matter same about a particle as gas, liquid or solid.
To learn more about states of matter refer to the link:
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velocity of sound in solid is more than that in liquid.why?
Velocity of sound travels faster in solids than in liquids, and faster in liquids than in gases because "the density of solids is higher than that of liquids, meaning that the particles are closer together."
Answer:
Explanation:
Due to the fact that sound is caused by vibrations, it's more noticeable in liquid because the vibrations may cause ripples in the liquid
Body Systems Directly Involved (Give at Least 2)
Cartoon
13. Ouch! You step on a tack and jump away without even thinking. Then you decide to pick up the tack and place it back in a desk drawer.
I need the second one the nervous system and...
Answer:
Nervous system and immune system
Explanation:
The nervous system is involved because you immediately jumped away, that ur brain and nerves initiating the fight or flight response. The immune system is involved because the tack most likely pierced your skin, so your immune system needs to work to make sure the wound does not get infected.
define specific heat capacity
•1. Identify the four inner/terrestrial planets.
Answer:
1) Mercury
2) Venus
3) Earth
4) Mars
Explanation:
Answer:
The for inner/terrestrial planets are Mercury, Venus, Earth and Mars
Explanation:
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Have a nice day and I hope it helps!
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-- XxFTSxX
3. A man hits a 0.2 kg golf ball with a force of 4
N. at what rate will the golf ball
accelerate?
Answer:
Force(f)= mass x acceleration
Acceleration (a) is the rate of change in velocity.
F=4N
M=0.2kg
a=F/M
a=4/0.2
a=20m/s^2
Explanation:
Answer:
the answer would be 20 m/s^2
Explanation:
A mass of 2.8 kg lies on a frictionless table,
pulled by another mass of 4.9 kg under the
influence of Earth's gravity.
The acceleration of gravity is 9.8 m/s2.
2.8 kg
4.9 kg
What is the magnitude of the acceleration
a of the two masses?
Answer in units of m/s2.
Answer:
17.15 m/s²
Explanation:
The formula for force is ;
F= m*a where m is mass of object 1 and a is acceleration due to gravity
The force, F , used in pulling the mass is ;
4.9 * 9.8 =48.02 N
Applying the formula for force to get acceleration
F= m*a
48.02 = 2.8 * a
a= 48.02 / 2.8
a= 17.15 m/s²
The PE of the box that is on a 2.0 m high self is 1600 J. What is the power expelled to lift the box to this height in 10.0 seconds?
Answer:
160 W
Explanation:
Power is the ratio of work to time:
(1600 J)/(10 s) = 160 J/s = 160 W
A spaceship is traveling at 24,000 m/sec. At T=5 sec, the rocket trusts are turned on. At T=55 sec, the spaceship reaches a speed of 29,500 m/sec. Whats the spaceships acceleration?
Answer:
480m/s²
Explanation:
Acceleration is the change in velocity of a body with respect to time;
Acceleration = change in velocity/change in time
change in velocity = 29,500 - 24,000
change in velocity= 5,500
Change in time = 55 - 5
change in time = 50secs
Substitute into the formula;
spaceships acceleration = 24000/50
spaceships acceleration = 480 m/s²
Hence the spaceships acceleration is 480m/s²
An artificial satellite orbits Earth at a speed of 7800 m/s and a height of 200 km above Earth’s surface. The satellite experiences an acceleration due to gravity of
A39 m/s2
Bless than 39 m/s2 but greater than 9.8 m/s2
C9.8 m/s2
Dless than 9.8 m/s2 but greater than zero
Answer: less than 9.8 m/s^2 but greater then zero
Explanation:
Gravitation law
The gravitational acceleration experienced by the satellite is 9.26m/s².
Therefore, Option D) less than 9.8 m/s2 but greater than zero is the correct answer.
Given the data in the question;
Speed or Velocity of the artificial satellite; [tex]v = 7800m/s[/tex]Height of satellite above the Earth; [tex]h = 200km = 200000m[/tex]
To keep the satellite in orbit, a centripetal force is required, this is provided by the gravitational force.
Hence, [tex]F_{centripetal } = F_{gravity}[/tex]
That is; [tex]\frac{mv^2}{r} = mg[/tex]
divide both sides by "m"
[tex]\frac{v^2}{r} = g[/tex]
Here, v is the velocity, g is the gravitational acceleration experienced by the satellite, r is the distance of the satellite from the center of the EARTH.
Diameter of the Earth; [tex]D_{Earth} = 12742 km = 12742000m[/tex]
Radius of the Earth; [tex]R_{Earth} = \frac{12742000m}{2} = 6371000m[/tex]
So,
Distance of the satellite from the center of the EARTH; [tex]r = R_{Earth} + h = 6371000m + 200000m = 6571000m[/tex]
Now we substitute our values into the equation
[tex]\frac{v^2}{r} = g[/tex]
[tex]g = \frac{(7800m/s)^2}{6571000m} \\\\g = \frac{60840000m^2/s^2}{6571000m}\\\\g = 9.26m/s^2[/tex]
The gravitational acceleration experienced by the satellite is 9.26m/s².
Therefore, Option D) less than 9.8 m/s2 but greater than zero is the correct answer.
Learn more; https://brainly.com/question/7282772
A dog playing fetch starts at rest and accelerates at 4.5m/s2 north. It takes the dog 7 seconds to catch the ball. What was the speed of the dog when he caught the ball?
Answer:
31.5m/s
Explanation:
Given the following
acceleration a = 4.5m/s²
Time t= 7secs
Required
Final speed v = ?
Using the equation of motion
v = u+at
v = 0+4.5(7)
v = 31.5m/s
Hence the speed of the dog is 31.5m/s
A piece of glass weights 25 g in air, 16.77g in water at 4C and 16.89g in water at 60C. Find the mean coefficient of cubical expansion of water between 4C anf 60C, taking the coefficient of linear expansion of glass as 8*10^6
sorry i think so i dont exactly know i am sorry
Explanation:
As a certain amount of water is cooled from room temperature until it reaches 4 °C, its volume drops. The density reduces as the volume increases below 4 °C. Therefore, water's greatest density occurs at 4 degrees Celsius.
What coefficient of cubical expansion of water?Water has an unusual trait called anomalous expansion, which causes it to enlarge rather than compress when the temperature drops from 4 °C to 0 °C, and it becomes less dense.
At temperatures not far below zero degrees Celsius, water ice is unique for having low coefficients of static and dynamic friction that range from 0.04-0.02, but as the temperature drops, these numbers rise.
Therefore, When a metal sheet's temperature rises by one degree, its coefficient of area expansion is calculated as the increase in surface area per unit of original surface area.
Learn more about coefficient here:
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You fill a car with gasoline. The car now has... ( what energy)
Answer:
Chemical Potential Energy Energy
Energy is the capacity for doing work or supplying heat. When you fill your car with gasoline, you are providing it with potential energy. Chemical potential energy is the energy stored in the chemical bonds of a substance.J
Explanation:
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.
How far will a car travel in 30 seconds at 12 m/s
Answer:
30*12=360m,it would travel 360 m.
1) Which of the following is not a type of energy?
A: Thermal
B: Potential
C: Kinetic
D: Frictional