Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
Suppose you fill two rubber balloons with air, suspend both of them from the same point, and let them hang down on strings of equal length. You then rub each with wool or on your hair so that the balloons hang apart with a noticeable separation between them. Make order-of-magnitude estimates of (b) the charge on each
The charge on each balloon is 100nC or 1.2 × 10^-7 C
Consider two balloons of diameter 0.200m each with a mass of 1.00g hanging apart with 0.0500m separation on the ends of string making angles of 10.0° with the vertical.
The charge on each balloon can be found from
[tex]F_{e} = \frac{k_{e}q^{2} }{r^{2}} \\q = \sqrt{\frac{k_{e}q^{2} }{r^{2}}} \\\\q = \sqrt{\frac{(2\times10^{-3N}(0.25m)^{2}}{8.99\times10^{9}N\cdotm^{2}/C^{2}}\\[/tex]
[tex]q = 1.2\times10^{-7}C[/tex] or 100nC
An electric charge is the property of matter where it has more or fewer electrons than protons in its atoms. Electrons carry a negative charge and protons carry a positive charge. The matter is positively charged if it contains more protons than electrons and negatively charged if it contains more electrons than protons.
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5. Define joint
answer asap plz and ty
Answer:
A point at which parts of an artifical structure are joined
what feature of the mtvr enables improved stopping control by rapidly adjusting air pressure to the brakes to prevent wheel lockup
Answer:
anti-lock braking system
Explanation:
A sound wave from a police siren has an intensity of 100.0 W/m² at a certain point; a second sound wave from a nearby ambulance has an intensity level that is 10 db greater than the police siren's sound wave at the same point. What is the sound level of the sound wave due to the ambulance?
The sound level of the sound wave due to the ambulance is 140.
What do you mean by sound?In terms of physics, the sound is a vibration that travels through a transmission medium like a gas, liquid, or solid as an acoustic wave. Sound is the reception of these waves and the brain's perception of them in terms of human physiology and psychology. Only acoustic waves with frequencies between roughly 20 Hz and 20 kHz, or the audio frequency range, can cause a human to have an auditory sensation. These are sound waves with wavelengths ranging from 17 meters (56 ft) to 1.7 millimeters in the air at atmospheric pressure (0.67 in). Ultrasounds are sound waves with a frequency higher than 20 kHz that are inaudible to humans. Infrasound refers to sound frequencies below 20 Hz. Animals of different species have different hearing ranges.
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A large meteoroid enters the Earth's atmosphere at a speed of 20.0 km/s and is not significantly slowed before entering the ocean. (b) If we assume the meteoroid survives the impact with the ocean surface, what is the (initial) Mach angle of the shock wave the meteoroid produces in the water?
If the meteoroid survives the impact, the Mach angle of the shock wave in water is 4.40°.
The square root of the proportion between the elastic force and the inertia force of a flowing fluid is known as the Mach number. Mach Angle (M) = The Mach Number (M). It is described as the Mach cone's halved angle.
A huge meteoroid travels at a speed of v (object) = 20.0 km/s as it enters the atmosphere and does not experience much braking before hitting the water.
Now,
v(object) = 20 km/s =20 × 10³ m/s
The speed of sound in seawater is:
v(sound) = 1533 m/s
The Mach angle in seawater is given as:
θ = sin⁻¹ ( v(sound) / v(object) )
θ = sin⁻¹ ( 1533 / 20 × 10³ )
θ = 4.40°
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Using your knowledge of the wave nature of sound, EXPLAIN who heard the basketball hit the backboard first, the ESPN cameraman or photographer? Explain your answer.
A - The camera man
B - the photographer under Miami’s goal.
Answer:
I can not see the image, so i will answer in a general way.
As you know, the sound behaves like a wave, this means that the sound needs some time to cover a given distance. An example of this motion can be seen when you drop a little stone in water, and you can see how the waves expand.
This means that the one who will hear the sound first, will be always the one that is closer to the source of the sound, in this case, the sound comes from the ball hitting the backboard, then the one who is closer to the backboard will hear the sound first.
Abe uses a wheelbarrow to move soil from his garden to a new flowerbed. He exerts an average force of 185 N while pushing the wheelbarrow, and he does 6.1 kJ of work while moving each load of soil. How far is he moving the soil?
Answer:
The distance he moved the soil is 32.97 m.
Explanation:
Given;
force exerted on the wheelbarrow, F = 185 N
work done in moving the soil, w = 6.1 kJ = 6100
The work done in moving the soil is given as;
Work done = force x distance he moved the soil
W = F x d
d = W / F
d = (6100) / (185)
d = 32.97 m
Therefore, the distance he moved the soil is 32.97 m.
A wire is formed into a circle having a diameter of 10.0 cm and is placed in a uniform magnetic field of 3.00mT . The wire carries a current of 5.00 A. Find (a) the maximum torque on the wire.
The maximum torque on wire is 0.12 x [tex]10^{-3}[/tex] N-m.
We have current carrying wire in a form of a circle placed in a uniform magnetic field.
We have to find the maximum torque on the wire.
What is the formula to calculate the torque on a wire placed in a uniform magnetic field.The torque on a wire placed in a uniform magnetic field is given by -
[tex]$\tau = IAB\;sin\theta[/tex]
According to the question, we have -
Diameter of wire (D) = 10 cm
Therefore -
Radius of wire (r) = 5 cm = 1/20 meter.
Magnetic field (B) = 3 mT = 3 x [tex]10^{-3}[/tex] T
I = 5 A
Using the formula for torque -
[tex]$\tau = IAB\;sin\theta[/tex]
For maximum torque -
[tex]\theta[/tex] = 90
Therefore -
[tex]$\tau = IAB[/tex] = 5 x 3.14 x [tex]\frac{1}{20}[/tex] x [tex]\frac{1}{20}[/tex] x 3 x [tex]10^{-3}[/tex] = 0.12 x [tex]10^{-3}[/tex] N-m.
Hence, the maximum torque on wire is 0.12 x [tex]10^{-3}[/tex] N-m.
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How has the Michelson-Morley experiment helped present-day scientists?
Michelson-Morley experiment helped present-day scientists by explaining how light travels through space and time.
What is an Experiment?This is referred to as a procedure which is carried out by scientists in other support or refute a hypothesis and an example of such is the Michelson-Morley experiment which helped explain some properties of light.
This experiment was able to explain how light travels in different media and the velocity in which such occurs. It was also discovered that light has a constant speed of light which helped to establish different mathematical relationships between various parameters and helped present-day scientists discover more.
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10. Does the Earth's magnetic field protect us from the Sun's particles? What are the auroras?
In an early spring, the warm sunshine melts snow on a sidewalk. A puddle of liquid water forms. How do the water particles change as the snow melts into liquid water?
1.)A tank travels at a rate of 10.0 km/hr for 12.00 minutes, then at 15.0 km/hr for 8.00
minutes, then turns 180 degrees at 20.0 km/hr for 12.00 minutes. What is the total
distance covered in km by the tank? What is the average speed for the complete trip in
m/s? What is the change of position of the tank? What is its average velocity?
Given
Equation
Find
Diagram
12.00 min = 0.2 hr
8.00 min = 0.15 hr
Total distance:
(10.0 km/hr) (0.2 hr) + (15.0 km/hr) (0.15 hr) + (20.0 km/hr) (0.2 hr)
= 8.25 km
Average speed:
(10.0 km/hr + 15.0 km/hr + 20.0 km/hr) / 3
= 15 km/hr
Change in position:
(10.0 km/hr) (0.2 hr) + (15.0 km/hr) (0.15 hr) - (20.0 km/hr) (0.2 hr)
= 0.25 km
Average velocity:
(10.0 km/hr + 15.0 km/hr - 20.0 km/hr) / 3
≈ 1.67 m/s
Justify the shape of energy pyramids
The speed of sound through argon is shown.
A 3 column by 3 row table.
Column 1 is titled Element and includes the following entries: Argon (gas), Argon (liquid).
Column 2 is titled Temperature (degrees Celsius) and includes the following entries: 27, negative 1.86
. Column 3 is titled Speed of Sound (meters per second) and includes the following entries: 323, 813.
If argon could exist as a solid, what would best represent the speed through solid argon?
10 m/s
250 m/s
500 m/s
3200 m/s
Answer:
3200
Explanation:
Answer:
D
Explanation:
how does extreme pressure affect the volume occupied by a real gas compared to the prediction of the ideal gas law
At extreme pressure, the volume of the real gas will be more compared to the prediction of the ideal gas law.
Ideal Gas Law gives PV = nRT, where
P - pressure of the gas
V - Volume of the gas
R - Gas constant
T- Temperature
n - number of particles
It says that high pressure decreases the volume of the gas occupied.
But ideal gas law fails for real gases. In the case of real gases, the gas molecules interact together and gives rise to its volume when high pressure is applied. The assumptions of Ideal gas law includes that the particles should not be able to interact with each other and it doesn't work at low temperature and high pressure.
So for real gases, extreme pressure increases the volume of the gas which does not agree with the prediction of ideal gas law.
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Does sound travel faster through steel or oxygen?
Answer:
Steel
Explanation:
Sound waves travel over 17 times faster through steel than through air.
Answer:
Steel
Explanation:
This is because solid objects molecules are more packed together, therefore it travels faster, in which time oxygen by 17 times faster
When running a long distance during the Texas summer which of the following would happen?
A. an increase in the rate of digestion
B. a decrease in the rate of breathing
C. a decrease in the speed of the plus
D. an increase in the Production of sweat
Answer:
Answer choice D!
Explanation:
When it comes to running during a hot day, the human body responds to extensive periods of heat by producing sweat. Sweat is necessary in order of cooling down the body, so that is why I figured it would be that answer. I hope this helped!
Please answer quick :)))
For each of the objects below determine the following:
(a) The forces that do work on the object.
(b) The amount of work done by each force.
(c) The net work done on the object.
meaning of anode and cathode
Answer:
An anode is an electrode through which conventional current (positive charge) flows into the device from the external circuit, while a cathode is an electrode through which conventional current flows out of the device.
Explanation:
Soccer player kicks a soccer ball with a force of 1300N. the soccer ball hits the player with a force of what
Answer:
The traffic light pulling upward on earth with a 1500 N force.
Explanation:
what is 19.2×108 minutes in hours? 3.200×109 h 3.200 times 10 to the power of 9 end power, , , h, 1.152×1011 h 1.152 times 10 to the power of 11 end power, , , h, 3.200×107 h 3.200 times 10 to the power of 7 end power, , , h, 1.152×107 h
Answer: the answer is 3.200×107 h
Explanation:
here's proof, honestly had no idea either so i just guessed, but hope this helps!
What is the quantity name for the derived unit kg/m^3?
A car weighing 12,000 N is parked on a 36° slope. The car starts to roll down the hill. What is the acceleration of the car?
Answer: 5.8 m/s squared
Explanation: just got that question lol
What is the acceleration of a 7 kg mass pushed by a 3.5 N force?
Answer:
0.5m/s²
Explanation:
F =m x a
3.5 = 7 x a
a = 3.5 /7
a = 0.5m/s ²
While the Earth is revolving around the sun, less direct sunlight is reaching the Northern Hemisphere than the Southern Hemisphere. What season is it in the Northern Hemisphere? (1 point)
Responses
winter
autumn
spring
summer
Answer:
winter
Explanation:
winter because the sun is not reaching the nothern hemisphere directly so the season inthe nothern hemisphere is winter.
and also it cannot be autumn because autumn is a season for leaves falling.
and also it cannot be spring because spring is the season for growth.
and also it cannot be summer because sumer is the season for the sun rays reaching directly on the earth.
HOPE THIS HELPS.
a ball initially rolling at 10 m/s comes to a stop in 25 seconds. how far does it travel during this time interval\
An object is undergoing simple harmonic motion. Throughout a complete cycle it:____.
a. Has varying acceleration
b. Has varying amplitude
c. Has constant speed
d. Has varying mass
e. Has varying period
The correct answer is option A: Has varying acceleration
An object is undergoing simple harmonic motion. Throughout a complete cycle, it has varying acceleration.
In Physics, simple harmonic motion(SHM) refers to the periodic motion or back-and-forth movement of a particle through a central position or equilibrium point.
In SHM, the maximum position of the particle on one side is equal to the extreme displacement of the particle on the opposite side.
To put it simply, SHM is a type of motion in which the object moves along a straight line having a particular acceleration proportional to the displacement and its direction is always towards the central fixed position i.e O.
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A player hits a ball with a bat. The action is the force of the bat against the ball.
What is the reaction to this force?
Answer:
Force of the ball against the bat
Explanation:
Newton's third law of motion states that for every action, there is an equal and opposite reaction. When a player hits a ball with a bat, the force the player exerted on the ball through the bat gave the ball a push force in the forward direction. This is an action force. Now that an action has been initiated, there must be a reaction according to Newton's third law of motion. The magnitude of the force on the ball equals the magnitude of the force on the bat. The direction of the force on the ball is opposite to the direction of the force on the ball. The ball will give the bat an equal and opposite force trying to push the bat backward by resisting the impact of the bat. This is the reaction. The ball will only move if the applied force is able to overcome the resisting force by the bat
Where;
is the action force of the bat against the ball.
is the equal and opposite reaction force of the ball towards the ball.
a parallel beam of * particles with fixed kinetic energy is normally incident on a piece of gold foil. (a) if 100 * particles per minute are detected at 20 , how many will be counted at 40 , 60 , 80 , and 100
A parallel beam of * particles with fixed kinetic energy is normally incident on a piece of gold foil. (a) if 100 * particles per minute are detected at 20, 20 will be counted at 40, 60, 80, and 100.
What is kinetic energy?In physical science, the dynamic energy of an article is the energy that it has because of its movement. It is characterized as need might have arisen to speed up a body of a given mass from rest to its expressed speed. Active energy is the development energy of an item. Active energy can be moved among objects and changed into different sorts of energy. Nonetheless, it isn't impacted by the climate beyond the article or framework, like air or level. Then again, motor energy is the energy of an item or a framework's particles moving. In spite of expected energy, the dynamic energy of an article is comparative with other fixed and moving items present in its nearby climate.
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Complete the following sentences.
mento
When you drop a ball, it falls to the ground,
This happens because the
pulls the ball
towards it with a force called
I
Forces are measured in units called
(Total 3 marks)