Answer:
Let x be the overhang of the plank
(4 - x) = Y portion of plank less the overhang
Y / 2 M g = clockwise torque due to weight of plank
40 x = counterclockwise torque due to weight of woman
(4 - x) M g / 2 = 40 x
(4 - x) M g = 80 x (I)
4 M g = (80 + M g) x (II)
x = 4 M g / (80 + M g) = 4 / (80 / M g + 1)
x would be shorter with an increase in M
if x were 1 then
4 M g = 80 + M g using (II)
M = 80 / (3 g) = 2.72 kg
Check: use x = 1 in equaton (I)
3 M g = 80
M = 80 / (3 * 9.8) = 2.72 kg
Select the star life cycle that is accurate.
A. Nebula, star of two stellar mass, supernova, black hole
B. Star of three stellar masses, red supergiant, supernova, neutron
star
C. Supernova, star of three stellar masses, black hole, nebula
D. Nebula, white dwarf, red giant, black hole
Answer:
B according to the picture
Explanation:
Star of 3 stellar masses => red supergiant=>supernova=>neutron star
Star of three stellar masses, red supergiant, supernova, neutron star are the star life cycle that is accurate. Therefore, the correct option is option B.
A star's life cycle is as follows: star formation inside a nebula, evolution into a sequence star, sustained nuclear fusion for a long time, exhaustion of fuel at some point, and gravitational core collapse with resulting high pressures and temperatures.
They typically consist of heated plasma held together by a strong gravitational force and are self-luminous. The thermonuclear process between helium and hydrogen that takes place in a star's core causes it to glow brilliantly. Star of three stellar masses, red supergiant, supernova, neutron star are the star life cycle that is accurate.
Therefore, the correct option is option B.
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Some electronic devices operate on a DC voltage of 7.5 V. To obtain 7.5 V DC from a 120-V (rms) AC line, first the voltage is dropped to 7.5 V (rms) AC by a transformer, and then the 7.5 V AC is converted to 7.5 V DC by a rectifier circuit involving diodes. Consider a device of resistance 15 Ω connected to the 7.5-V DC output of the rectifier. Assuming no power loss anywhere, what is the rms current, in amperes, in the secondary winding? Again assuming no power loss anywhere, what is the rms current, in milliamperes, in the primary winding?
The rms current, in amperes, in the secondary winding is 0.5 A and the rms current, in milliamperes, in the primary winding is 31.25 mA.
Output current
The rms current, in amperes, in the secondary winding is calculated as follows;
V = IR
I = V/R
I = 7.5 / 15
I = 0.5 A
Input currentThe rms current, in milliamperes, in the primary winding is calculated as follows;
[tex]\frac{I_p}{I_s} = \frac{V_s}{V_p} \\\\I_p = \frac{V_sI_s}{V_p}\\\\I_p = \frac{7.5 \times 0.5}{120} \\\\I_p = 0.03125\\\\I_p = 31.25 \ mA[/tex]
Thus, the rms current, in amperes, in the secondary winding is 0.5 A and the rms current, in milliamperes, in the primary winding is 31.25 mA.
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Convert 25 meters per second (m/s) to kilometers per hour (km/hr).
Оа
9.0 x 10^-2 km/hr
Oь
9.0 x 10^-1 km/hr
Ос
9.0 x 10^1 km/hr
Od
9.0 x 10^2 km/hr
Answer:
9 x 10^1 km/hr
Explanation:
25 m/s x 3600 sec / hr x 1km / 1000 m = 90 km/hr
Which is an example of radiation?
Answer:
A burning candle emits radiation in the form of heat and light. The Sun emits radiation in the form of light, heat, and particles. Uranium-238 decaying into Thorium-234 emits radiation in the form ofalpha particles.
Answer:
the sun
Explanation:
the sun emits radiation
How do landforms and rock layers support the plate tectonic theory
A sample from a meteorite that landed on Earth has been analyzed, and the result shows that out of every 1,000 nuclei of potassium-40 originally in the meteorite, only 250 are still present, meaning they have not yet decayed. How old is the meteorite (in yr)?
I have to make a presentation about ultrasound diagnostic (it's for physics). Does someone know more about that topic? I need to explain how does ultrasound show insides of human body.
*sorry if my english isn't that good, im from Cro
Answer: Okay so I don't know much but from what I do know
Ultrasound emits sound waves into the body and what bounces back is what they can see the grey shape is what is closest. It's all micro sound waves and cannot hurt an unborn baby.
Explanation:
Not sure if this is correct but it is what I remember being told.
Hope this helps!
What is the index of refraction of a liquid if the angle of incidence in air is 35 degrees and the angle of refraction is 14 degrees?
A. A cord passing over an easily turned pulley (one that is both massless and frictionless) has 7kg mass hanging from one end and a 9kg mass hanging from the other end as shown below. G 7.0 kg 9.0 ks This arrangement is known as Atwood's machine. Calculate the (i). acceleration of the masses (ii). tension in the cord. [2.5
Answer:
M g = M a = a (9 - 7) kg with the two masses going in different directions
(7 + 9) kg * g = a * 2 kg 2 kg effective in prducing acceleration
a = 16 / 2 * g = 9.8 m/s^2 / 8 = 1.23 m/s^2
M1 a = T - M1 * g T producing upward acceleration of 1.23 m/s^2
T = 7 (a + g) = 7 * 11 = 77 N
Check:
M2 a = M2 * g - T M2 producing downward acceleration
T = M2 (g - a) = 9 * (9.8 - 1.23) = 77 N
The atmosphere has mass and produces friction as objects move through it.
true or false
true
Explanation:
It has friction when objects move through it.
CPR combines which two processes to keep a person alive until medical personnel arrive?
A. Rescue breathing and chest compressions
B. Chest compressions and RICE
C. Rescue breathing and AED
Your answer will be A. Rescue breathing and chest compressions.
_______is the resistance to motion offered by an object sliding over a surface
friction is the force that resists the sliding or rolling of an object over another.
A mass of 100kg is acted on by a 400N force acting vertically upward and a 600N force acting at a 45 degrees angle.Calculate the vertical component of the acceleration.The local acceleration of gravity is 9.8 m/s2. A.1.56 B.-1.56 C.-2.43 D.2.43 . E. 3.5
Answer:
A 1.56 see below
Explanation:
I will assume the 45 degree force is upward
vertical component = 600 sin 45 = 424.26 N
added to the other vertical force will total 824.26 N
F = ma
824.26 = 100 * a shows a = 8.24 m/s upward
Now we have to assume the mass is ALSO acted on by gravity and this value is given as 9.8 ( so downward is positive)
9.81 - 8.24 = 1.56 m/s^2
Why is simple machine important ?...
Answer: Simple Machines are useful and important because they reduce effort or extend the ability of people to form tasks beyond their normal capabilities . So they help us in our daily lives by reducing the amount of effort it takes for humans to perform certain tasks .
HOPE IT HELPS YOU .PLEASE GIVE BRAINLIEST .THANKS .
Which of the following was NOT one of Ghana's chief trading exports?
A. Gold
B. Ivory
C. Horses
Answer:
ivory. ..................
How do you find the range of a data set?
Answer: You take the biggest number and subtract it from the smallest number.
Explanation: Hope this helps.
Answer:
Subtract the minimum data value from the maximum data value to find the data range.
Explanation:
[tex]Hope[/tex] [tex]this[/tex] [tex]helps![/tex]
Help with these questions
Answer:
sorry im not good at math so sorry i cant help
Explanation:
27. What do we mean when we say that a simple machine uses mechanical advantage to
make a "tradeoff" between force and distance?
Answer:
Work = Force * Distance definition of work
W = F * d
If one uses 1/2 the force to move an object, then he must move the force thru twice the distance to get the same work output.
A(n) __________ __________ is made with an electromagnet that is free to spin between two permanent magnets
Answer:
Like a galvanometer, an electric motor contains (a switch, an electromagnet) that is free to rotate between the poles of a permanent, fixed magnet. 9.
Q5- Knowing now that your mood might affect your memory, what strategies could you employ to assist your memories and make sure that you forget less information when you are having a good time?
After a boater runs out of gas a boater considers dropping the motor into the water to create waves describe the resuming motion of the boat and explains why the boaters plan will not help him reach shore ????
The boat will swing back and forth about the same location, never reaching the land. Due to which the boaters plan will not help him reach shore.
Describe boat motion?The ship rocks back and forth as the wind and waves press against it. Similar to swiveling on a chair, yaw spins the ship on an unseen central line.
Waves travelling perpendicular to the ship's motion might create this, changing the ship's heading or direction.
The motion of the motor will be identical to that of water molecules. Because there is a wave on the water surface,The motor will move in lockstep with the water particle.
The particles of the medium only vibrate perpendicular to the wave propagation as the wave travels through the water surface, but they are not moved from their initial position.
As a result, the boat will swing back and forth about the same location, never reaching the land.
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It the mass of the foot is 10kg and it is moving at 5m/s, what is the momentum of the leg?
A 49.0 kg child sits on the top of a slide that is located 1.80 m above the ground. After her descent, the child reaches a velocity of 3.00 m/s at the bottom of the slide. Calculate how efficiently the potential energy is converted to kinetic energy. Round to the nearest tenth.
For the potential energy is converted to kinetic energy is mathematically given as
n=24.44%
What efficiency of the potential energy is converted to kinetic energy?
Generally, the equation for the potential energy is mathematically given as
Ei=mgh
Ei=49.0\*9.81* 1.8
Ei=865.24J
Final total energy
K.E=0.5mv^2
K.E=0.5*49.0* (3.00)^2
K.E=211.5J
In conclusion, efficiency
n=Ef/Ei*100
n=211.5*865.24*100
n=24.44%
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A particle has a velocity that is 70 % of the speed of light and weighs 206.8 times the mass of an electron. Find the wavelength of this particle?
For a particle that has a velocity that is 70 % of the speed of light and weighs 206.8 times the mass of an electron, the wavelength of this particle is mathematically given as
W= 739.47
What is the wavelength of this particle?Generally, the equation for the 70 % of the speed of light is mathematically given as
70% of 3x10^8 = 2.1x10^8 m/s
Therefore
206.8*9.11x10^-31 = 1.88x10^-28 kg
In conclusion, The wavelength equation isTThe
wavelength= plancks constant / (mass*velocity)
Where
Plancks constant = 6.62x10^-34 m^2 kg/s
W=6.62x10^-34 / (1.88x10^-28/2.1x10^8)
W= 739.47
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PLEASE HELP!! Lab: Electromagnetic Induction
Answer:
I think this is the answer
Explanation:
what is kinematics ?
explain ~
Kinematics is the branch of physics and a subdivision of classical mechanics concerned with the geometrically possible motion of a body or system of bodies without consideration of the forces involved. :)
Answer:
Kinematics is a branch of mechanics that deals with pure motion, without reference to the masses or forces involved in it.
Explanation:
Ex. X=2t+1 here x is related to t which is time(function of time)
If the slump and subsequent flow continue migrating uphill and more material flows downhill, which of the following are a hazard? (select all that apply)
A. The homes will be damaged.
B. The roadway will be damaged.
C. Utility power poles will be damaged.
D. More agricultural land will be unfarmable.
The hazard from more material flows downhill are:
The roadway will be damaged.More agricultural land will be unfarmable.Utility power poles will be damagedWhat is Hazard?This is a condition which has the potential to cause damage or injury to a person or property.
Materials flowing downward means that there will erosion which may damage the roads, land for agriculture and utility poles.
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I
same 7 kg ball.
9. A 10 N force and a 40 N force are acting in opposite direction on the
ball? What is the magnitude of the acceleration of the ball?
Answer:
Here, m=10 kg
The resultant force acting on the body is
F=(98N)2+(6N)2=10N
Let the resultant force F makes an angle θ w.r.t. 8N force.
From figure, tanθ=8N6N=43
The resultant acceleration of the body is
a=mF=10kg10N=1ms−2
The resulatnt acceleration is along the direction of the resulatnt force.
Hence, the resultant acceleration of the body is 1 ms−2 at an angle of tan−1(43) w.r.t. 8N force.

Electromagnetic waves(such as light, gamma rays, microwaves, etc.) exhibit a longitudinal wave form.
True
False
Answer:
False - Electromagnetic waves are transverse waves - they do not need a particular medium for transmission - as sound waves in air (longitudinal waves)
An object has a momentum of 4,000 kg-m/s and a mass of 115 kg. It crashes into another object that has a mass of 100 kg, and the two objects stick together. If the momentum is conserved, what is the new velocity of the combined object? Round to the nearest hundredth.
Answer:
18.60 m/s
Explanation:
Original momentum = mv = 4000 with m = 115
after collision m = 115 + 100 = 215 kg
but the total momentum is still the same (conserved)
4000 = 215 v shows v = 18.60 m/s
Answer:
18.60
Explanation: