Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
If an oxygen molecule traveling at the rms speed bounces back and forth between opposite sides of a cubical vessel of 0.10 m on a side, what is the average force the molecule exerts on one of the walls of the container? Assume the molecule’s velocity is perpendicular to the walls it hits.
Answer:
1.25x10^-19N
Explanation:see attached file pls
5. i) Name two devices based on interaction between magnetic field and current carrying conductor.
Answer:
some common devices that use current carrying conductors and magnetic fields are electric motor electric generator loudspeakers microphones and measuring instruments like galvanometer ammeter and voltmeter
Can anyone tell me how to read a micrometer screw gauge I want very clear instructions.
Explanation:
Things you need to know:
Accuracy refers to the maximum error encountered when a particular observation is made.
Error in measurement is normally one-half the magnitude of the smallest scale reading.
Because one has to align one end of the rule or device to the starting point of the measurement, the appropriate error is thus twice that of the smallest scale reading.
Error is usually expressed in at most 1 or 2 significant figures.
Tape
Equipment: It is made up of a long flexible tape and can measure objects or places up to 10 – 50 m in length. It has markings similar to that of the rigid rule. The smallest marking could be as small as 0.1 cm or could be as large as 0.5 cm or even 1 cm.
How to use: The zero-mark of the measuring tape is first aligned flat to one end of the object and the tape is stretched taut to the other end, the reading is taken where the other end of the object meets the tape.
Ruler
Equipment: It is made up of a long rigid piece of wood or steel and can measure objects up to 100 cm in length. The smallest marking is usually 0.1 cm.
How to use: The zero-end of the rule is first aligned flat with one end of the object and the reading is taken where the other end of the object meets the rule.
Vernier Caliper
Equipment: It is made up of a main scale and a vernier scale and can usually measure objects up to 15 cm in length. The smallest marking is usually 0.1 cm on the main scale.
It has:
a pair of external jaws to measure external diameters
a pair of internal jaws to measure internal diameters
a long rod to measure depths
How to use: The jaws are first closed to find any zero errors. The jaws are then opened to fit the object firmly and the reading is then taken.
Micrometer Screw Gauge
Equipment: It is made up of a main scale and a thimble scale and can measure objects up to 5 cm in length. The smallest marking is usually 1 mm on the main scale (sleeve) and 0.01 mm on the thimble scale (thimble). The thimble has a total of 50 markings representing 0.50 mm.
It has:
an anvil and a spindle to hold the object
a ratchet on the thimble for accurate tightening (prevent over-tightening)
How to use: The spindle is first closed on the anvil to find any zero errors ( use the ratchet for careful tightening). The spindle is then opened to fit the object firmly (use the ratchet for careful tightening) and the reading is then taken.
A ball that rolls on the ground is initially propelled with a speed of 45 km / h and after 10 seconds it stops. Assuming you lost speed constantly, then: a) Calculate the acceleration b) Calculate the distance traveled.
Answer:
a) -1.25 m/s²
b) 62.5 m
Explanation:
Convert km/h to m/s:
45 km/h × (1000 m/km) × (1 h / 3600 s) = 12.5 m/s
a = Δv / Δt
a = (0 m/s − 12.5 m/s) / 10 s
a = -1.25 m/s²
Δx = ½ (v + v₀) t
Δx = ½ (0 m/s + 12.5 m/s) (10 s)
Δx = 62.5 m
A monkey is sitting at the top of a tree 25 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food, how should the person aim the arrow containing the food? Group of answer choices
Answer:
He should aim it at the monkey
Explanation:
The question is related to projectile motion of an arrow from a bow such that the arrow is able to reach a specific target
Therefore, since the monkey is going to drop from the tree the instant the person launches the food, then for the monkey to be able reach the food, we have;
Final level position of the launched food should be ≥ The level of the monkey
As the monkey is dropping from the tree the destination of the launched food should be at the monkey so that before the food gets to the position where the monkey was when launching the food with the arrow, the monkey will be slightly lower so as to be able to catch the food or return up the tree to get the food rather than the food falling to the ground.
The graph shows a wave that oscillates with a frequency of 60 Hz. Based on the information given in the diagram, what is the speed of the wave?
Answer:
900 cm/s or 9 m/s.
Explanation:
Data obtained from the question include the following:
Length (L) = 30 cm
frequency (f) = 60 Hz
Velocity (v) =.?
Next, we shall determine the wavelength (λ).
This is illustrated below:
Since the wave have 4 node, the wavelength of the wave will be:
λ = 2L/4
Length (L) = 30 cm
wavelength (λ) =.?
λ = 2L/4
λ = 2×30/4
λ = 60/4
λ = 15 cm
Therefore, the wavelength (λ) is 15 cm
Now, we can obtain the speed of the wave as follow:
wavelength (λ) = 15 cm
frequency (f) = 60 Hz
Velocity (v) =.?
v = λf
v = 15 × 60
v = 900 cm/s
Thus, converting 900 cm/s to m/s
We have:
100 cm/s = 1 m/s
900 cm/s = 900/100 = 9 m/s
Therefore, the speed of the wave is 900 cm/s or 9 m/s.
A charged particle with charge of 2 (uC) and mass 10-20 (kg) is traveling with velocity of 108 (m/s) in space. The charge reaches to a region in space with magnetic field of 0.05 (T) and experience a force of 8 (N) exerted by the magnetic field.
A- What is the angle between velocity of particle and magnetic field direction?
B- What is acceleration of charged particle while experiencing the force?
Answer:
Explanation:
A ) Let the angle be θ between magnetic field and velocity of charged particle
Force created on charged particle F
= Bqv sinθ, B is magnetic field , q is charge , v is velocity of charged particle
F = .05 x 2 x 10⁻⁶ x 10⁸ x sinθ
8 = 10 sinθ
sinθ = .8
θ = 53°.
B )
acceleration = force / mass
= 8 / 10⁻²⁰
= 8 x 10²⁰ m / s²
If a 3.5 gram ping pong ball were traveling to the right horizontally at 12 m/s, and a larger 12 g super ball were thrown directly behind it (also to the right) at 15 m/s so that the super ball bumped into and elastically collided with the ping pong ball, what would be the velocities of the two balls after the collision
Answer:
v = 14.32 m/s
Explanation:
According to the principle of conservation of linear momentum, both the momentum and kinetic energy of the system are conserved. Since the two balls are in the same direction of motion before collision, then;
[tex]m_{1} u_{1}[/tex] + [tex]m_{2} u_{2}[/tex] = ([tex]m_{1}[/tex] + [tex]m_{2}[/tex]) v
0.035 × 12 + 0.120 × 15 = (0.035 + 0.120) v
0.420 + 1.800 = (0.155) v
2.22 = 0.155 v
⇒ v = [tex]\frac{2.22}{0.155}[/tex]
= 14.323
The velocity of the balls after collision is 14.32 m/s.
A train whose proper length is 1200 m passes at a high speed through a station whose platform measures 900 m, and the station master observes that when the train passes it occupies exactly the entire length of the platform. What is the speed of the train?
Answer:
0.66c
Explanation:
Use length contraction equation:
L = L₀ √(1 − (v²/c²))
where L is the contracted length,
L₀ is the length at 0 velocity,
v is the velocity,
and c is the speed of light.
900 = 1200 √(1 − (v²/c²))
3/4 = √(1 − (v²/c²))
9/16 = 1 − (v²/c²)
v²/c² = 7/16
v = ¼√7 c
v ≈ 0.66 c
You are planning to go to a very cold place where the night temperature drops to -50°C.Which thermometer will you take with you - mercury or alcohol? Why?
Answer:
Explanation:
The range of mercury thermometer is - 37°C to 356°C . At temperature below - 37°C , mercury starts converting into solid so this thermometer becomes non- functional . Hence to measure temperature of - 50°C , alcohol thermometer is suitable . The range of alcohol thermometer is - 112° C to 78°C .
It has been a hot summer, so when you arrive at a lake, you decide to go for a swim even though it it nighttime. The water is cold. The next day, you go swimming again during the hottest part of the day, and even though the air is warmer the water is still almost as cold. Why?
(a) Water is fairly dense compared with many other liquids.
(b) Water remains in a liquid state for a wide range of temperatures.
(c) Water has a high bulk modulus.
(d) Water has a high specific heat.
Answer:
(d) Water has a high specific heat.
Explanation:
At night, when the temperature of earth goes down due to loss of heat , the temperature of water is lost slowly and temperature of land is lost fast because of high specific heat of water . Water loses as well as gains temperature comparatively slowly due to its high specific heat .
During daytime when earth gains heat , the temperature of land rises more rapidly than water so water appears cool even during daytime when land becomes hotter . It is also due to high heat holding capacity of water or due to high specific heat of water .
Since 1901, global surface temperatures have risen at an average rate of 0.13oF every ten years. In which way could the average increase in global temperatures influence Earth?
Answer:
The correct answer is "By increasing the amount of flooding because of rising sea levels".
Explanation:
The global temperature chart reflects an approximation across the whole planet's atmosphere. Owing to relatively stable entertain as well as the difficult-to-predict wind but instead, weather patterns structures, the temperature changes we perceive domestically as well as in brief periods could vary dramatically.Doubling the volume of floods due to rising water levels might also significantly affect the ordinary increase in energy consumption on Earth.The maximum pressure most organisms can survive is about 1000 times the atmospheric pressure. Only small, simple organisms such as bacteria can survive such high pressures. What then is the maximum depth at which these organisms can live under the sea (assuming that the density of seawater is 1025 kg/m3)
Answer:
h = 10000 m
Explanation:
The pressure applied at a depth of the liquid is given by:
P =ρgh
where,
P = Maximum Pressure to Survive = (1000)(Atmospheric Pressure)
P = (1000)(101325 Pa) = 1.01 x 10⁸ Pa
ρ = Density of sea water = 1025 kg/m³
g = 9.8 m/s²
h = maximum depth to survive = ?
Therefore,
1.01 x 10⁸ Pa = (1025 kg/m³)(9.8 m/s²)h
h = (1.01 x 10⁸ Pa)/(1025 kg/m³)(9.8 m/s²)
h = 10000 m
The time T in seconds for a pendulum of length L feet to make one swing is given by Upper T=2\pi \sqrt((L)/(36)). How long is a pendulum (to nearest hundredth) if it makes one swing in 2.1 seconds? Use 3.14 for \pi .
Answer:
3.6ft
Explanation:
Using= 2*π*sqrt(L/32)
To solve for L, first move 2*n over:
T/(2*π) = sqrt(L/32)
Next,eliminate the square root by squaring both sides
(T/(2*π))2 = L/32
or
T2/(4π2) = L/32
Lastly, multiply both sides by 32 to yield:
32T2/(4π2) = L
and simplify:
8T²/π²= L
Hence, L(T) = 8T²/π²
But T = 2.1
Pi= 3.14
8(2.1)²/3.14²
35.28/9.85
= 3.6feet
Why is hydraulic jack used ? Write.
Answer:
it is used because
It occupies less spaceheavy loads are easily movedminimum of effort is usedit is a bit lighter than screw jacks.They are also less likely to jam due to rust in the screw thread.
Hydraulic jacks are often used to lift elevators in low and medium rise buildings.
A hydraulic jack uses a liquid that is forced into a cylinder by a pump plunger.
mathematically boyle's law is
Explanation:
Boyles law is the pressure of a fixed mass of gas which is inversely proportional to its volume provided that the temperature is kept constant.
A patient had stunted growth,swelling on face,discolaration of hair and skin disease.the doctor advised him to eat a lot of pulses,grams,albumin of the egg and milk etc.,which is wrong with the patient?Explain in two sentences
Answer:
The patient is suffering from protein deficiency
Explanation:
Protein deficiency is characterized by symptoms such as stunted growth; skin, nail and hair problems, loss of muscle mass, and in extreme cases, kwashiorkor.
Deficiency in protein is usually corrected by taking foods rich in protein such as egg's albumin, milk, pulses, beans, etc; hence the advice of the doctor.
Which dog has the most kinetic energy?
O A. A dog of mass 13 kg running with speed 7 m/s
O B. A dog of mass 10 kg running with speed 8 m/s
O c. A dog of mass 14 kg running with speed 6 m/s
O D. A dog of mass 15 kg running with speed 5 m/s
SUBM
Answer:
C
Explanation:
Answer:
c. A dog of mass 14 kg running with speed 6 m/sation:
7.Why are we able to drink cold drink with straw from a bottle?
Explanation:
Because of air pressure
A ball is thrown vertically upwards from the roof of a building with an initial velocity of 30 m / s. If it stops in the air 220 m above the ground, what is the height of the building?
Answer:
175 m
Explanation:
Given:
y = 220 m
v₀ = 30 m/s
v = 0 m/s
a = -10 m/s²
Find: y₀
v² = v₀² + 2a (y − y₀)
(0 m/s)² = (30 m/s)² + 2 (-10 m/s²) (220 m − y₀)
y₀ = 175 m
Find “d” in the following figure
Answer:
16 m
Explanation:
Given:
v₀ = 4 m/s
a = 4 m/s²
t = 2 s
Find: Δx
Δx = v₀ t + ½ at²
Δx = (4 m/s) (2 s) + ½ (4 m/s²) (2 s)²
Δx = 16 m
The discharge of a stream is Choose one: likely to decrease downstream in arid regions and increase downstream in temperate regions. typically lower in spring than during summer. constant for the length of the stream. calculated by dividing its cross-sectional area by its velocity.
Answer:
likely to decrease downstream in arid regions and increase downstream in temperate regions
Explanation:
Arid regions are is a region with a severe lack of water, usually to the extent that affect the organisms living in the region. Arid regions are characterized by a very low depth of rainfall per year. Temperate region on the other hand experience more distinct seasonal change and wider temperature change. Temperate regions get a fairly large amount of rainfall per year.
In arid regions, the soil is very dry, and the rate of infiltration and percolation is high relative to the amount of rainfall available. The effect is that more water is infiltrated into the soil as you move downstream, leading to a decrease in the discharge of a stream as you move downstream. Most temperate region have soils that are usually saturated in the peak of the rainfall season, leading to a greater stream discharge as you move downstream.
3.27 moles of an ideal gas has a pressure of 125000 Pa at 15.0 ° C What is the volume of the gas?
Answer:
15.96 m³ (corrected to 2 d.p.)
Explanation:
Using idea gas law:
pV = nRT
pressure p = 125000 Pa
volume V = unknown
no. of moles n= 3.27 moles
ideal gas constant R = 8.3145 J K−1 mol−1
Temperature t (in Kelvins) = 15 + 273.15 = 288.15K
125000 x v = 3.27 x 8.3145 x 288.15
v = 15.96 m³ (corrected to 2 d.p.)
Answer:
0.0626 m^3
Explanation:
First, we know that the equation to calculate the behavior of gases is:
PV=nRT
Looking at the problem, we understand that we are needing to solve for V, which means we need to isolate V to solve for it.
The new equation will look something like this:
V=nRT/P
The last step is to simply plug in the remaining variables:
n=3.27
R=8.31 (that is not given but is a standard number that you will always use for "R"/ the ideal gas constant-it helps to right it down somewhere to reference it if you ever need it!)
P=125000
T=288 (the temp needs to be in degrees K, so take 15.0 degrees c and + 273)
Finally, when you input all of those, you will have something that looks like this:
V=(3.27*8.31*288)/125000
V=0.02608205 m^3
V= 0.0626 m^3 (rounded to 3 sig. figs)
I hope this was helpful and easy to understand!
Newton’s third law of motion explains the two forces namely ‘action’ and ‘reaction’ coming into action when the two bodies are in contact with each other. These two forces: *
(a) Always act on the same body
(b) Always act on the different bodies in opposite directions
(c) Have same magnitude and direction
(d) Acts on either body at normal to each other
Pls fast
(b) Always act on the different bodies in opposite directions
Answer:
b) Always act on the different bodies in opposite directions
Explanation:
b) Always act on the different bodies in opposite directions
For example:
If I am sitting on a sofa and I exert 370N and the sofa will exert -370N force. If the sofa doesn't exert force back, I won't be able to sit which means it will break.
Hope it helps ;) ❤❤❤
A load of 500N is carried by 200N effort in a simple machine having load distance 3m Calculate effort distance.
Answer:
2.5 mExplanation:
Load ( L ) = 500 N
Effort ( E ) = 200 N
Load distance ( LD ) = 3 m
Effort distance ( ED ) = ?
Now, Let's find the Effort distance ( ED )
We know that,
Output work = Input work
i.e L × LD = E × ED
plug the values
[tex]500 \times 3 = 200 \times ED[/tex]
multiply the numbers
[tex]1500 = 200 \times ED[/tex]
Swipe the sides of the equation
[tex]200 \: ED \: = 500[/tex]
Divide both sides of the equation by 200
[tex] \frac{200 \: ED}{200} = \frac{500}{200} [/tex]
Calculate
[tex]ED\: = 2.5 \: m[/tex]
Hope this helps..
best regards!!
A uniform string of length 10.0 m and weight 0.32 N is attached to the ceiling. A weight of 1.00 kN hangs from its lower end. The lower end of the string is suddenly displaced horizontally. How long does it take the resulting wave pulse to travel to the upper end
Answer: 0.0180701 s
Explanation:
Given the following :
Length of string (L) = 10 m
Weight of string (W) = 0.32 N
Weight attached to lower end = 1kN = 1×10^3
Using the relation:
Time (t) = √ (weight of string * Length) / weight attached to lower end * acceleration due to gravity
g = acceleration due to gravity = 9.8m/s^2
Weight of string = 0.32N
Time(t) = √ (0.32 * 10) / [(1*10^3) * (9.8)]
Time = √3.2 / 9800
= √0.0003265
= 0.0180701s
A snail at position 3 cm moves to position 20 cm in 8 seconds.
Answer: 17cm.
Explanation:
The equation you're using is:
Δd = df - di
Which means the change in position is equal to the final position minus the starting position. In this case that works out to 20cm - 3cm = 17cm. We're only interested in how much the snail moved, not how long it took to move, so even though they give a time it actually doesn't matter for this question.
Did to gravity, the moon has a much smaller acceleration than earth. How do you think that would affect the period of pendulum?
I think any pendulum would swing slower on the moon than it would on Earth.
The time it takes a pendulum to go through a complete back and forth swing is:
Time period = 2 π √(length/gravity)
You can see that 'gravity' is in the denominator of the fraction, so the smaller gravity gets, the longer the period gets.
To be a little bit more technical, the period is inversely proportional to the square root of gravity.
So the period for a complete swing on the moon would be √(9.8/1.6) times as long as the complete swing of the same pendulum on Earth.
That number is roughly 2.47 .
So, for every 1 second that a pendulum takes to swing back and forth once on Earth, the same pendulum would take 2.47 seconds to do it on the moon.
Answer:
based on my opinion....
as we know that gravity in moon are less than gravity in earth.. since the force of gravity is less on the moon, the pendulum would swing slower at the same length, angle
and the frequency would be less.
I hope this helps
f(x)= 10x-5
What is the value of f-1(-4) ?
Answer:
[tex]f^{-1}(-4) = \frac{1}{10}[/tex]
Explanation:
Firstly finding [tex]f^{-1}(x)[/tex]
So,
[tex]f(x) = 10x-5[/tex]
Substitute [tex]y = f(x)[/tex]
[tex]y = 10x-5[/tex]
Exchange the values of x and y
[tex]x = 10y-5[/tex]
Solving for y
[tex]x = 10y-5[/tex]
Adding 5 to both sides
[tex]10y = x+5[/tex]
Dividing both sides by 10
[tex]y = \frac{x+5}{10}[/tex]
Replace [tex]y = f^{-1}(x)[/tex]
[tex]f^{-1}(x) = \frac{x+5}{10}[/tex]
For x = -4
[tex]f^{-1}(-4) = \frac{-4+5}{10}[/tex]
[tex]f^{-1}(-4) = \frac{1}{10}[/tex]
Answer:
[tex]\frac{1}{10}[/tex]
Explanation:
f(x) = y (output)
y = 10x - 5
Switch variables.
Solve for y.
x = 10y - 5
x + 5 = 10y
x/10 + 1/2 = y
[tex]f^{-1}(x)[/tex] = 1/10x + 1/2
Put x as -4.
1/10(-4) + 1/2
-4/10 + 1/2
-4/10 + 5/10
= 1/10
Two forces are acting on a 5.00 kg mass. One of the forces is 10.0 N south and the other is 15.0 N east. The direction of the acceleration of the mass is
Answer:
The direction of the acceleration of the mass is due East.
Explanation:
Data obtained from the question include the following:
Mass = 5 kg
Force due South = 10 N.
Force due East = 15 N.
To know which direction the acceleration of the mass will go, we must first obtain the resultant force.
This is illustrated below:
Resultant force = 15 – 10 = 5 N
Therefore, the resultant force is 5 N due East since the larger force is due East
Since the resultant force is due East, it means that the mass will accelerate toward the East.
According to the question,
Mass = 5 kgForce due south = 10 NForce due east = 15 NThe resultant force will be:
= [tex]15-10[/tex]
= [tex]5 \ N[/tex]
Since the larger force is due east. Thus the answer above is right.
Learn more about force here:
https://brainly.com/question/1844505