Expository essay "Climate change in Fiji"
Answer: Climate change poses to the tourism development in Fiji islands. It shows the adverse effects of the changing climate and the dangers pose by the tourism activities and also pose a major hazard for the local people in the region. It also deals with the dangerous carbon emissions and CO2 effect on the landscape, food, water, energy.
The pacific is the world`s largest ocean with a surface area of 175 million sq km and constitutes for 40% of the planet`s waters. Located in the tropical latitudes, it covers more than half the globe`s circumference. Temperature of the surface water in the western tropical regions is always more than 28 ÌŠC over a depth of several hundred meters. This makes up the world`s storage of thermal energy for exchange with atmosphere. Here the interaction between atmosphere and ocean is most extreme and influences the climate not only regionally but planet-wide. The nations of the pacific are obscured human settlements absorbed in this vast fluid universe. The ocean is the most important factor controlling the environment and life.
A uniform 140 g rod with length 57 cm rotates in a horizontal plane about a fixed, vertical, frictionless pin through its center. Two small 30 g beads are mounted on the rod such that they are able to slide without friction along its length. Initially the beads are held by catches at positions 11 cm on each sides of the center, at which time the system rotates at an angular speed of 23 rad/s. Suddenly, the catches are released and the small beads slide outward along the rod. Find the angular speed of the system at the instant the beads reach the ends of the rod. Answer in units of rad/s.
Answer:
The correct answer is "12 rad/s"
Explanation:
The given values are,
Mass of rod,
M = 140 g
i.e.,
= 0.14 kg
Length,
L = 57 cm
i.e.,
= 0.57 m
Mass of beads,
M = 30 g
i.e.,
= 0.03 kg
Angular speed,
r = 11 cm
i.e.,
= 0.11 m
Now,
The inertia of rods will be:
= [tex]\frac{1}{12}ML ^2[/tex]
On substituting the values, we get
= [tex]\frac{1}{12}\times 0.14\times (0.57)^2[/tex]
= [tex]0.0037905 \ kg-m^2[/tex]
The inertia of beads will be:
= [tex]mr^2[/tex]
On substituting the values, we get
= [tex]0.03\times (0.11)^2[/tex]
= [tex]0.000726 \ kg-m^2[/tex]
The total inertia will be:
= [tex]Inertia \ of \ rods+Inertia \ of \ beads[/tex]
= [tex]0.0037905 + 0.000726[/tex]
= [tex]0.0045165 \ kg-m^2[/tex]
now,
The angular speed of the system will be:
⇒ [tex]L_1w_1=L_2w_2[/tex]
On substituting the values in the above equation, we get
⇒ [tex]0.0045165\times 23 = (0.0037905 + (0.03\times 0.285^2)\times 2 )\times w_2[/tex]
⇒ [tex]0.1038795 = 0.0037905 + (0.00243675\times 2 )\times w_2[/tex]
⇒ [tex]w_2 = 12 \ rad/s[/tex]
A cart moves with negligible friction or air resistance along a roller coaster track. The cart starts from rest at the top of a hill of unknown height. It then goes down that first hill and up another circularly shaped hill of height 10 meters and radius 15 meters. The ride is designed so that the cart just barely loses contact with the track at the top of the second hill (10 meters above ground level). What is the height of the starting hill relative to ground
Answer:
hinit = 17.5 m
Explanation:
Assuming no friction present, the mechanical energy must be conserved, which means that at any point of the trajectory, the sum of the gravitational potential energy and the kinetic energy must keep the same.At the top of the hill, since it starts from rest, all the energy must be potential, and we can express it as follows:[tex]E_{o} = U_{o} = m*g*h_{init} (1)[/tex]
When the car arrives to the top of the second hill, as we know that it is lower than the first one, the energy of the car, must be part gravitational potential energy, and part kinetic energy.We can express this final energy as follows:[tex]E_{f} = U_{f} + K_{f} = m*g* h_{2} + \frac{1}{2} *m*v_{f} ^{2} (2)[/tex]
In order to find hinit, we need to make (1) equal to (2), and solve for it.In (2) we have the value of h₂ (10 m), but we still need the value of the speed at the top of the second hill, vf.Now, when the car is at the top of the hill, there are two forces acting on it, in opposite directions: the normal force (upward) and the weight (downward).We know also that there is a force that keeps the car along the circular track, which is the centripetal force.This force is just the net downward force acting on the car (it's vertical at the top), and is just the difference between the weight and the normal force.If the cart just barely loses contact with the track at the top of the second hill, this means that at that point the normal force becomes zero.So, the centripetal force must be equal to the weight.The centripetal force can be expressed as follows:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} (3)[/tex]
We have just said that (3) must be equal to the weight:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} = m*g (4)[/tex]
Simplifying, and rearranging, we can solve for vf², as follows:[tex]v_{f}^{2} = R*g (5)[/tex]
Replacing (5) in (2), simplifying and rearranging in (1) and (2) we finally have:[tex]h_{init} = h_{2} + \frac{1}{2} R = 10m + 7.5 m = 17.5 m (6)[/tex]
A projectile is thrown with a velocity of 40 m/s, 45 degrees above the +x-axis. Determine its initial x-velocity and its initial y-velocity.
x-component is V·cos(angle)
y-component is V·sin(angle)
When the angle is 45°, its sin and cos are both 1/2·√2 .
Vx = 20·√2 = 28.28 m/s
Vy = 20·√2 = 28.28 m/s
what is the reason for timing more than one oscillation in a simple pendulum
Answer:
Time period is the time taken by the body to complete one oscillation and it is noted more than once to get accurate reading from averaging of all the observed values.
When you measure the mass of an object you are also measuring its what
Here ya go-!
Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. The basic SI unit of mass is the kilogram (kg).
(um im sorry if its wrong-)
What is Gravity?
PLEASE ANSWER
Answer:
Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun.
Please mark as brainliest
Have a great day, be safe and healthy
Thank u
XD
Answer:
GRAVITY:
In physics, gravity is the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.
1. Why is the flow of electrons from A to B?
2. What's the difference between flow of current & flow of electrons and why ar they opposite?
1. because A is more negative than B. A is -1000 V (we can imagine that A has excess 1000 electrons), in other, B which +3000 V can be assume that B need 3000 elctrons to be neutral. So, the electron will flow from A to B.
2. Electrons being negatively charged flow from the negative terminal to the positive terminal of the voltage source. So, the actual direction of current should be from negative to positive terminal. However, the conventional direction had already been established. So, the current flow is considered in the direction opposite to the direction of flow of electrons. (from topperlearning dot com)
Which types of reactions are also redox reactions?
Answer:
Your ans is B)
Explanation:
Hope its right
if wrong firgive me
please help me with the working too.
Answer:
1 : b 2: d
Explanation:
(WILL MARK BRAINLIAST)( 1 answer question.. look the photo)
As the cars come closer together, the amount of potential energy in the system:
-Increases
-Decreases
-Stays the same
Answer:
increases
Explanation:
due to less speed
given that two vectors A=i,2j-2k and B=6i+3j+2k find A +B
Answer:
7i, 5j, 0k
Explanation:
Add up the two vectors.
Add
i+i 1+6 = 7i
j+j 2+3 = 5j
k+k -2+2 = 0k
therefore A+B = (7i, 5j, 0k)
Charging by Contact examples
Answer:
the hair and the comb are both neutral
faraday's law states that the potential difference can be increased by... (choose all that apply)
1. using static electricity instead of current electricity
2. increase the number of coils, increase the strength of the magnet
3. using a bunch of small magnets
4. increasing the time used to power up an electromagnet
5. increase the speed of the magnet
Id say its the last option of the fourth option
Explanation:
Answer:
1:increase the number of coils, increase the strength of the magnet
2:increase the speed of the magnet
3: increasing the time used to power up an electromagnet
Explanation:
1). Increasing the number of turns of wire in the coil – By increasing the amount of individual conductors cutting through the magnetic field, the amount of induced emf produced will be the sum of all the individual loops of the coil, so if there are 20 turns in the coil there will be 20 times more induced emf than in one piece of wire.
2). Increasing the speed of the relative motion between the coil and the magnet – If the same coil of wire passed through the same magnetic field but its speed or velocity is increased, the wire will cut the lines of flux at a faster rate so more induced emf would be produced.
3). Increasing the strength of the magnetic field – If the same coil of wire is moved at the same speed through a stronger magnetic field, there will be more emf produced because there are more lines of force to cut.
A police officer uses a radar gun that emits electromagnetic waves with a frequency of 10.525 GHz (1.0525 1010 Hz). Assume the police officer is at rest, and is aiming the radar gun at vehicles traveling either directly toward, or directly away from, the radar gun. Assume the speed limit is 110 km/h, as it is on many Canadian highways. The police officer observes reflected waves that have a frequency of 2460 Hz below the frequency of the emitted waves.
Required:
a. At what speed is the car moving?
b. Choose the two correct statements about this situation.
1. The car is moving toward the police officer.
2. The car is moving away from the police officer.
3. The police officer should not cite the driver for speeding.
4. The police officer should cite the driver for speeding.
Answer:
Explanation:
For Doppler effect in radar the formula is as follows
Δf = f₀ x 2v /c
Δf is change in frequency in reflected wave , f₀ is original frequency , v is velocity of source and c is velocity of right .
Δf = 2460 Hz , f₀ = 1.0525 x 10¹⁰ Hz , v = ? c is velocity of light .
2460 = 1.0525 x 10¹⁰ x 2 v / 3 x 10⁸
2460 = 105.25 x 2 v / 3
v = 2460 x 3 / (105.25 x 2 )
v = 35 .06 m /s .
(b)
Since the observed frequency is less , the source is moving away from the observer .
option (2) is correct .
how much force is needed to accelerate a 2500kg car at a rate of 4m/s2
Answer:
10,000 N
Explanation:
Using Newton's Second Law of Motion, Force = Mass*Acceleration.
Plugin 2500 kg for the mass and 4 m/s^2 for the acceleration.
Force = 2500 kg*4 m/s^2 = 10000 Newtons
(SI unit of force is Newtons)
PLEASE HELP ME WITH ONE QUESTION
If 1000 J of heat energy is lost from a piece of hot metal which is placed into a cup of cool water, how much energy is gained by the water?
Answer:
1000J
Explanation:
According to the law of calorimetry;
Heat lost by cold substance = Heat gained by hot substance
If 1000 J of heat energy is lost from a piece of hot metal,
heat lost by hot substance = 1000J
Since we are to determine how much energy is gained by the water, using the law
Heat lost by hot metal = heat gained by the water
Hence heat gained by the water = 1000J
PLEASE HELP ME WITH THIS ONE QUESTION
A tuning fork of 500 Hz is struck in a room with a speed of sound of 340 m/s. What is the distance between a point of rarefaction and the next compression point, in the resulting sound?
Answer:
0.34 m
Explanation:
From the question,
v = λf................ Equation 1
Where v = speed of sound, f = frequency, λ = Wave length
Make λ the subject of the equation
λ = v/f............... Equation 2
Given: v = 340 m/s, f = 500 Hz.
Substitute these values into equation 2
λ = 340/500
λ = 0.68 m
But, the distance between a point of rarefaction and the next compression point, in the resulting sound is half wave length
Therefore,
λ/2 = 0.68/2
λ/2 = 0.34 m
Hence, the distance between a point of rarefaction and the next compression point, in the resulting sound is 0.34 m
An electric motor supplies 2,500 Watts of power in a 220 V circuit. What is the resistance of the motor? Be sure to include the proper units in your answer. Remember... Ω is the unit for Resistance.
Answer:
R = 19.36 ohms
Explanation:
Given that,
The power of an electric motor, P = 2500 Watts
The voltage of the circuit, V = 220 V
We need to find the resistance of the motor. We can find it as follows :
[tex]P=\dfrac{V^2}{R}\\\\R=\dfrac{V^2}{P}\\\\R=\dfrac{(220)^2}{2500}\\R=19.36\ \Omega[/tex]
So, the resistance of the motor is 19.36 ohms.
A human body consists of
Answer:
60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Explanation:
Please please help I'm stuck!!!
Answer: iDc im in 3grade
Explanation:sorry
A capacitor is made from two hollow, coaxial, iron cylinders, one inside the other. The inner cylinder is negatively charged and the outer is positively charged; the magnitude of the charge on each is 11.5 pC. The inner cylinder has a radius of 0.550 mm, the outer one has a radius of 7.20 mm, and the length of each cylinder is 13.0 cm.
(a) What is the capacitance?
(b) What applied potential difference is necessary to produce these charges on the cylinders?
Answer:
A)2.811 × 10^-12 F
B)4.09V
Explanation:
(a) What is the capacitance?
Capacitance of coaxial cylinder can be determined using below expresion
C= (2π ε0 L)/ Ln[ rb/ra]
Where
ε0= permittivity of free space= 8.85×10^−12 Fm^-1
L= length of each cylinder =13.0 cm= 13×10^-2m
rb= radius of outer cylinder= 7.20 mm= 7.20×10^-3m
ra=radius of inner cylinder=0.550 mm= 0.550×10^-3 m
If we substitute the values we have,
C= (2π ε0 L)/ Ln[ rb/ra]
C= ( 2 × π × 8.85×10^−12 ×13×10^-2) / Ln[
7.20×10^-3/0.550×10^-3]
C=( 7.2288×10^-12 )/2.5729
C=2.811 × 10^-12 F
B) (b) What applied potential difference is necessary to produce these charges on the cylinders?
Vba= Q/C
Where Vba=potential difference
Q= charge on each = 11.5 pC. = 11.5×10^-12
C= capacitance= 2.811 × 10^-12 F
If we substitute the values we have
Vba=(11.5×10^-12)/2.811 × 10^-12
= 4.09V
A baseball is thrown a distance of 20 m what is its speed if it takes 0.5 seconds to cover the distance
Answer:
40m/s
Explanation:
help, it's an emergency !!!!!!!
a box is slides down a slope
Answer:
120 N
Explanation:
From the question given above, the following data were obtained:
Angle (θ) = 35°
Mass (m) = 15 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal force (N) =?
The normal force acting on the object can be obtained as:
N = mg × Cosθ
N = 15 × 9.8 × Cos 35
N= 147 × 0.8192
N = 120 N
Therefore, the normal force acting on the object is 120 N
Please help
The period of an oscillation is measured to be 0.0833 seconds. What is
the frequency of this oscillation? *
1.0833 Hz
0.287 Hz
9.8 Hz
12 Hz
0.007 Hz
Answer:
your
answer is
12.004
Is there more than one way to get two objects with identical masses to balance? How?
Answer: yes you can
Explanation: because i i have a trying and a squar that have the same mass it would caunt as the same
Yes we can get two objects with identical masses to balance in this type of scenario.
What is Mass?
This is defined as the quantity of matter which is present in a body at a given point in time.
The two objects with identical masses can be made to balance through the use of a string and a pulley.
Read more about Mass here https://brainly.com/question/19385703
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An elevator motor in a high-rise building can do 3500 kJ of work in 5 min. Find the power developed by the motor. Explain if you can plz
Answer:
P = 11666.6 W
Explanation:
Given that,
Work done by the motor, W = 3500 kJ
Time, t = 5 min = 300 s
We need to find the power developed by the motor. Power developed is given by :
[tex]P=\dfrac{E}{t}\\\\P=\dfrac{3500\times 10^3}{300}\\\\P=11666.7\ W[/tex]
So, the required power is 11666.6 W.
A student sets up a standing wave of wavelength 6 meters in a coiled spring by moving his hand up and down twice each second. What is the velocity of the wave?
Answer:
Velocity = 12 m/s
Explanation:
Given the following data;
Wavelength = 6 meters
Period = 0.5 seconds. This is due to the fact that the student is moving his hand up and down twice each second.
To find the velocity;
Velocity = wavelength * frequency
But, frequency = 1/period
Frequency = 1/0.5
Frequency = 2
Substituting the values into the velocity formula, we have;
Velocity = 6 * 2
Velocity = 12 m/s
Therefore, the velocity of the wave is 12 meters per seconds.
A police car drives with a constant speed of 70km/hr. how long will it take to cover a distance of 135km?
(btw, it's a physics question:-)
Explanation:
36. How long does it take a car to slow down from a speed of 54 km/h to 32 km/h over a distance of 65 m? Answer in seconds. 37.