Answer:
(a) 4.82 m/s
(b) The simmer need to head 57.05° upstream of the river to reach a point directly opposite the river
(c) 4.024 seconds
Explanation:
The parameters given are;
The speed of the swimmer = 5.75 m/s
The direction of the resultant motion = 40° downstream
The speed of the current = x m/s
Therefore in a given second, we have that the swimmer moves 5.75 meters across the river while the current moves x meters downstream
Which gives;
[tex]tan(40^{\circ}) = \dfrac{x}{5.75}[/tex]
x = 5.75 × tan(40°) = 4.82 m/s
The speed of the current = 4.82 m/s
(b) If the swimmer swims at a direction θ to reach a point, p, directly opposite the river, we have;
The resultant speed across the river will be the swimmer's swimming speed which is 5.75 m/s
5.75² = y² + 4.82²
y = √(5.75² - 4.82²) = √9.78
tan(θ) = 4.82/(√9.78) = 1.54
θ = tan⁻¹(1.54) = 57.05°
The simmer need to swim 57.05° upstream to reach a point directly opposite the river
(c) If the river is 15 m wide, we have;
Time (t) = Distance/speed
The component of the swimmer's speed directly across the river = 5.75/(tan(57.05°)
The component of the swimmer's speed directly across the river = 3.73 m/s
The time, t, to cross the river is therefore;
t = 15/3.73 = 4.024 seconds
Which property of argon is used in light bulbs?
Answer:
Argon belongs to zero group, i.e., is a noble gas and thus is inert. Hence it will not react with the hot filaments. Hence it is used in fluorescent and incandescent light bulbs to stop the oxygen in the light bulbs from corroding the hot tungsten filament.
Explanation:
I NEED HELP PLEASE, THANKS!
Identify each of the following as a conductors or insulators. Explain.
-cloth
-dry wood
-tap water
-glass
Answer:
Cloth:
It is an insulator since it can't let electricity pass through
Dry Wood:
It is an insulator and can't conduct electricity.
Tap Water:
It is a good conductor as it contains dissolved salts.
Glass:
It is an insulator since it can't let electricity pass through.
To which category does galaxy #4 belong? Why does it belong in this category?
Answer:
The Galaxy IV satellite belongs to the HS-601 model category. It was engineered by Hughes Space and Communications Company (HSC)
Explanation:
The Galaxy IV belong in this category because it is a communications satellite. It was built for direct television broadcasting, for private business networks and mobile communications.
Cheers!
if a room is closed for 2-4 hours then when we open the door we need a little bit of more energy than the actual energy and feel someone is pushing the door from the back side . what is the reason behind it ? which force is that?
Answer:
The reason is because the pressure of the air inside the room drops with time which makes opening the door to require an increased amount of force to make up for the reduced pressure inside the room
Explanation:
From the kinetic theory of gases we have the following relation;
[tex]v_{rms} = \sqrt{\dfrac{3 \cdot K \cdot T}{m} }[/tex]
[tex]p = \dfrac{n \cdot MW \cdot v^2_{rms} }{3 \cdot V}[/tex]
Where:
K = Boltzmann constant
T = Temperature
m = Mass
MW = Molecular weight
V = Volume
[tex]v_{rms}[/tex] = Root mean square velocity
Whereby the room door is closed, the kinetic energy of the air particles will be used up such that the average velocity of the particles will decrease, given that the volume of the room is constant, the pressure inside the room will drop below the original pressure outside the room such that the force on the door due to the outside pressure is larger than the force on the door from inside the room requiring a larger amount of force to overcome the resistance of the now higher outside pressure force.
Which property of sugar makes it different from white crystalline sand?
Answer:
The property of sugar which makes it different from sand is that sugar can dissolve in water. Explanation: however the power of dissolving of sand is not present. This is due to the presence of interaction between sugar and water.
Explanation:
I hope that was useful
define hardware.Give 2 examples
Answer:
They are the physical parts of a computer.
examples :monitor,keyboard,system unit and mouse.
Calculate the volume of the part of the sphere that will be immersed in the mercury when the density of the sphere is 7800kg/metre cubic and volume of 136centrimetre cubic and the density of the mercury is 13600kg/metre cubic
Answer:
78 cm³
Explanation:
The Volume Immersed = (density of object/ density of fluid) x Volume of Object
Vi = (7800/13600) x 136 = 78 cm³
I NEED HELP PLEASE, THANKS! Describe each Newton Law. :)
Explanation:
1st- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
2nd- states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. (most important law)
3rd- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. (law of action/reaction)
The displacement from equilibrium of an oscillating weight suspended by a spring and subject to the damping effect of friction is given by y(t) = 2e−t cos 4t, where y is the displacement (in centimeters) and t is the time (in seconds). Find the displacement when t = 0, t = 1 4 , and t = 1 2 . (Round your answers to two decimal places.)
Note that the correct times are t = 0, t = 1/4, t = 1/2. You can tell from the spaces between the two digits. i.e 1&4 and 1&2
Answer:
y(0) = 2.00 cm
y(1/4) = 1.56 cm
y(1/2) = 1.21 cm
Explanation:
This is a very simple exercise, the displacement of the oscillating weight from equilibrium has already been modeled by the equation:
[tex]y(t) = 2e^{-t} cos 4t[/tex]
Where y = displacement ( in cm)
and t = time (in seconds)
The task is to find the displacement when t = 0, 1/4 and 1/2
When t = 0 s
[tex]y(0) = 2e^{0} cos 4(0)\\y(0) = 2* 1*1\\y(0) = 2.00 cm[/tex]
When t = 1/4 s
[tex]y(1/4) = 2e^{-1/4} cos 4(1/4)\\y(14) = 2e^{-1/4} cos (1)\\y(1/4) = 1.56 cm[/tex]
When t = 1/2
[tex]y(1/2) = 2e^{-1/2} cos 4(1/2)\\y(14) = 2e^{-1/2} cos (2)\\y(1/2) = 1.21 cm[/tex]
A stone is dropped from a tower of height 3600cm.Find the velocity by which it strike the ground.Also,find the time taken to reach the ground.
Answer:
Explanation:
Here h=36m, a=g=10m/s, u=0
Use s=ut+(1/2)at^2
36=0*t+(10t^2)/2
time=2.68 sec
As from the formula of final velovity, v=(2gh)^1/2
v=(2*10*36)^1/2
v=(720)^1/2
v=26.83………This is the final velocity
Answer:
Explanation:
s = vit + 1/2 gt*2
36 = 0 + 1/2 x 9.8 x t*2
t*2 = 7.34
t = 2.7sec
now,
2gs = vf*2 - vi*2
2 x 9.8 x 36 = vf*2 - 0
vf*2 = 705.6
vf = 26.5m/s
I NEED HELP PLEASE, THANKS! :) Why is it a good idea to touch a metal pole, or similar conductor, before filling up a car with gas?
Answer:
While filling up the gas, a static discharge can take place which is really dangerous for us. It can even ignite a fire at the gas station. Touching the metal pole or any conductor will pass all of the charge into the Earth and thus we'll keep safe.
Answer:
It is a good idea to touch a metal pole or similar conductor before filling up a car with gas because it will discharge any static electricity on you, making it safer for everyone.
Explanation:
A right triangle ABC has sides /AB/ =9cm, /BC/=12cm find /AC/ and angles ACB and ABC if angle BAC= 90°
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A 50.0-g hard-boiled egg moves on the end of a spring with force constant k = 25.0 N/m. Its initial displacement is 0.300 m. A damping force Fx=−bvxF
x
​
=−bv
x
​
acts on the egg, and the amplitude of the motion decreases to 0.100 m in 5.00 s. Calculate the magnitude of the damping constant b.
Answer:
The correct answer will be "0.022 kg/s".
Explanation:
The given values are:
Initial amplitude,
A₁ = 0.3 m
Final amplitude,
A₂ = 0.1 m
Mass of a egg,
m = 50.0 g i.e., 0.050 kg
Time,
t = 5 sec
As we know,
⇒ [tex]A_{2}=A_{1}e^{(-\frac{b}{2m})t}[/tex]
So that, the damping constant will be:
⇒ [tex]b=\frac{2m}{t} log \frac{A_{1}}{A_{2}}[/tex]
On putting the estimated values, we get
⇒ [tex]b=\frac{2\times 0.050}{5}log \frac{0.3}{0.1}[/tex]
⇒ [tex]=\frac{0.1}{5} log \frac{0.3}{0.1}[/tex]
⇒ [tex]=0.02 \ log 3[/tex]
⇒ [tex]=0.0219 \ kg/sec \ or \ 0.022 \ kg/s[/tex]
Which refers to a measure of how acidic or basic a solution is? a]pH b]solubility c]reactiveness d]hardness
Answer:
Option(a) i.e" pH" is the correct answer to the given question .
Explanation:
The main objective of pH value is to determining whether the solution is the acidic or the basic solution.The pH is determining the solution whether it is basic or acidic with the help of there pH value .The range of the pH value is from 0 to 14 with the following parameter it determines whether the solution is basic ,acidic or the neutral solution .
If pH value is 7 then it is neutral solution .If pH value is greater then 7 then the solution is then it is basic solution .If the pH value is less then 7 then the solution is the Acidic solution .All the other option are not determining that whether the solution is acidic or the basic solution that's why these are incorrect option .
Answer:
the answer is A pH
got it right 2020
Explanation:
Which form of government shares goods and services equally, and the political power is disturbing among the people?
Answer:
Socialist
Explanation:
Answer: socialist
Explanation: A socialist form of government is where the goods and services are equally shared, and the political power is distributed among the people.
A radioactive isotope has a half-life of 2 hours. If a sample of the element contains 600,000 radioactive nuclei at 12 noon, how many radioactive nuclei would be left at 6 pm?
Answer: There will be 75258 nuclei left at 6 pm.
Explanation:
a) half-life of the radioactive substance:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
[tex]t_{\frac{1}{2}}=\frac{0.69}{k}[/tex]
[tex]k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{2hours}=0.346hours^{-1}[/tex]
b) Expression for rate law for first order kinetics is given by:
[tex]A=A_0e^{-kt}[/tex]
where,
k = rate constant
t = time for decomposition = 6 hours ( from 12 noon to 6 pm)
A = activity at time t = ?
[tex]A_0[/tex] = initial activity = 600, 000
[tex]A=600000\times e^{-0.346\times 6}[/tex]
[tex]A=75258[/tex]
Thus there will be 75258 nuclei left at 6 pm.
Austin kicks a soccer ball with an initial velocity of 18.0 m/s at an angle of 35.0°. What are the horizontal and vertical components of the initial velocity? Round your answers to the nearest tenth. vix = m/s viy = m/s
Answer:
(vix, viy) = (14.7 m/s, 10.3 m/s)
Explanation:
The velocities of interest are ...
(vix, viy) = (vi)(cos(35°), sin(35°)) = (18 m/s)(cos(35°), sin(35°))
(vix, viy) = (14.7 m/s, 10.3 m/s)
Answer:
First one = 14.7
Second one = 10.3
Explanation:
EDGE
quick question plz.........If force acting on a body of mass 40kg is doubled. By how much will be the acceleration change?
A. By a factor of 2
B. By a factor of 3
C. By a factor of 4
D. remains the same
Answer:
if i'm not mistaken the answer is A
The new acceleration will be increase by the factor of 2. Hence, option (A) is correct.
Given data:
The mass of body is, m = 40 kg.
We can use the Newton's second law to obtain the result of given problem. As per the Newton's second law, "The force applied by the given object is equal to the product of mass of object and the magnitude of acceleration of object". Then the expression is,
F = ma
a = F/m .....................................................................(1)
Here,
F is the force.
m is the mass.
a is the acceleration.
if the force acting in the mass of body of 40 kg is doubled. Then new acceleration will be,
F' = ma'
(2F) = ma'
2(F/m) = a'
From equation (1) we get,
a' = 2a
Thus, we can conclude that the new acceleration will be increase by the factor of 2. Hence, option (A) is correct.
Learn more about the Newton's Second Law here:
https://brainly.com/question/19860811
HELLLP PLEASE || the graph below shows a conversion of energy for a skydive jumping out of a plane and landing safely on the ground. which energy is represented by line A? A) Potential B) Thermal C) Kinetic D) Total Energy
Answer: I maybe wrong but i'm pretty sure its C) Kinetic energy
11. What is the wavelength of an earthquake wave if it has a speed of 5000 m/s and a frequency of 10 HZ
step#1
step#2
step#3
Answer:
500 m
Explanation:
The applicable relation is ...
wavelength = speed/frequency
wavelength = (5000 m/s)/(10 cycles/s) = 500 m/cycle
The wavelength is 500 meters.