Answer:
a.) 20.4 h
b.) 3.46 km/h
Explanation:
Given that an English Channel is 35 km wide at its narrowest point, which is where most swimmers attempt to cross north to south from England to France. The current across this portion of the English Channel runs at about 2 km/h east to west.
a.) If a swimmer has a relative velocity to the shore of 3 km/h north to south, The resultant velocity (Vr) will be achieved by using Pythagoras theorem
Vr = [tex]\sqrt{2^{2} + 3^{2} }[/tex]
Vr = [tex]\sqrt{4 + 9}[/tex]
Vr = [tex]\sqrt{12}[/tex]
Vr = 3.46 m/s
To get how long it take her to cross the 35 km distance, Let us first find acceleration by using third equation of motion.
[tex]V^{2} = U^{2} + 2aS[/tex]
Where U = 0
Substitute all the parameters into the equation
[tex]3.46^{2} = 2 x a x 35[/tex]
11.97 = 70a
a = 11.97/70
a = 0.17 km/h^2
The time can be found by using equation
V = U + at
let U = 0
3.46 = 0.17t
t = 3.46/0.17
t = 20.35h
b. What must be her velocity relative to the water if she has a velocity of 3 km/h north to south relative to the shore?
her velocity relative to the water will be
Vr = [tex]\sqrt{2^{2} + 3^{2} }[/tex]
Vr = [tex]\sqrt{4 + 9}[/tex]
Vr = [tex]\sqrt{12}[/tex]
Vr = 3.46 m/s
What is an amu?
lol I'm asking alot of questions
What is temperature? Using the example of the pot of boiling water, describe how you think temperature is related to thermal energy.
Answer:
An example would be "The soup is boiling hot and has a temperature of 100 °C, whereas the water in the tub is just comfortably warm, with a temperature of about 38 °C. Although the water in the tub has a much lower temperature, it has greater thermal energy".
Explanation:
Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter.
PLS HELP THIS IS DUE IN TWO HOURS
Answer:
C
Explanation:
Which part of a DC generator keeps the electric current flowing in only one
direction?
A. The permanent magnets
B. The commutator
o
C. The power source
D. The wire coil
An insulated rigid tank initially contains 1.4-kg saturated liquid water and water vapor at 200°C. At this state, 25 percent of the volume is occupied by liquid water and the rest by vapor. Now an electric resistor placed in the tank is turned on, and the tank is observed to contain saturated water vapor after 20 min. Determine:
(a) the volume of the tank
(b) the final temperature
(c) the electric power rating of the resistor
Solution:
Mass of liquid water and water vapor in the insulated tank initially = 1.4 kg
Temperature = 200 °C
And 25% of the volume by liquid water is steam.
State 1
[tex]$m=\frac{V}{v}$[/tex]
[tex]$m=m_f+m_g$[/tex]
[tex]$1.4=\frac{0.25V}{v_f}+\frac{0.75V}{v_g}$[/tex]
[tex]$1.4=\frac{0.25V}{1.1565 \times 10^{-3}}+\frac{0.75V}{0.1274}$[/tex] (taking the value of [tex]$v_g$[/tex] and [tex]$v_g$[/tex] at 200°C )
[tex]$V=6.304 \times 10^{-3}$[/tex]
Now quality of vapor
[tex]$x=\frac{m_g}{m}$[/tex]
[tex]$=3.377 \times 10^{-3}$[/tex]
Internal energy at state 1 can be found out by
[tex]$u_1=u_f+xu_{fg}$[/tex]
[tex]$=850.65+3.377\times10^{-3}\times 1744.65$[/tex]
= 856.54 kJ/kg
After heating with the resistor for 20 minutes, at state 2, the tank contains saturated water vapor [tex]$v_2=v_g \text { and }\ x=1$[/tex]
Tank is rigid, so volume of tank is constant.
[tex]$v_g=v_2=\frac{V}{m}$[/tex]
[tex]$v_g=\frac{6.304\times 10^{-3}}{1.4}$[/tex]
[tex]$v_g=4.502 \times 10^{-3} \ m^3 /kg$[/tex]
Now interpolate the value to get temperature at state 2 with specific volume value to get final temperature
[tex]$T_2=360+(374.14-360)\left(\frac{0.004502-0.006945}{0.003155-0.006945}\right)$[/tex]
= 369.11° C
Internal energy at state 2
[tex]$u_2=2154.9 \ kJ/kg$[/tex]
Now power rating of the resistor
[tex]$P=\frac{m(u_2-u_1)}{t}$[/tex]
[tex]$P=\frac{1.4(2154.9-856.54)}{20 \times 60}$[/tex]
= 1.51 kW
Is Time and Light both connected in anyway?
Answer:
It is not connected by any way
You are an astronomer on planet tirth, which orbits a distant star. it has recently been accepted that tirth is spherical in shape, though no one knows its size. one day, you learn that on the equinox your sun is directly overhead in the city of tyene, located 750 kilometers due north of you. on the equinox, you go outside in alectown and observe that the altitude of your sun is 87.0 ∘.
Answer:
The circumference of planet tirth is [tex]C = 90000 \ km[/tex]
Explanation:
From the question we are told that
The distance of tyene from the observer is [tex]d = 750 \ km[/tex]
The altitude of the sun from the equinox is [tex]\theta_s = 87.0^o[/tex]
Generally given that on the equinox your sun is directly overhead in the city of tyene , then the altitude of the tyene from the equinox is [tex]\theta_e = 90 ^o[/tex]
Generally the angular distance between tyene and the sun as observed from the equinox is mathematically represented as
[tex]\theta _d = \theta_e - \theta_s[/tex]
=> [tex]\theta _d = 90 -87[/tex]
=> [tex]\theta _d =3^o[/tex]
Generally the ratio of [tex]\theta _d =3^o[/tex] to [tex]360^o[/tex] which is the total angle in a circle is equal to the ratio of [tex]d = 750 \ km[/tex] to the circumference of the planet
So
[tex]\frac{\theta_d}{360} = \frac{750}{C}[/tex]
=> [tex]\frac{3}{360} = \frac{750}{C}[/tex]
=> [tex]C = 90000 \ km[/tex]
I have a really long assignment I don't understand! please help
I can try and help whats it about?
Psychology:
_________ is focusing on something specific in the environment.
A.
Attention
B.
Stimuli
C.
Memory
D.
Rehearsal
The answer is A. Attention
Answer:
ans is a .attention
plsssssssssssss mark meeee brainlist
Explanation:
Reena has rolled down her toy car through a ramp. When she increases the height of the ramp (10 cm ) the car has travelled 5 metres and she increases the height of the ramp (13 cm) the car has travelled 6 metres . What happened when she raises the height of the ramp?
Answer:
As she raises the height of the ramp, the speed of the toy car decreases.
Explanation:
Speed is the ratio of the distance traveled by an object to the time taken.
i.e speed = [tex]\frac{distance}{time}[/tex]
From the given question, it would be observed that:
i. when the height of the ramp was 10 cm, the car traveled 5 meters.
ii. when the height of the ramp was increased to 13 cm, the car traveled 6 meters.
Therefore, an increase in the height of the ramp causes a decrease in the speed of the toy car so that the distance traveled per unit time increases. Showing that there is an inverse relationship between the height of the ramp and the speed of the toy car.
Which type of carbohydrate is the body unable to digest, but is still important for lowering cholesterol, balances glucose levels, and helps prevent overeating.
Answer:
Cellulose
Explanation:
Cellulose is the carbohydrate which is unable to be digested by body. Adding fiber's (cellulose) to one's diet reduces blood cholesterol level because soluble fiber dissolves in water to form a gel, which moves slowly through the intestines binding up fat, dietary cholesterol, bile salts, and sugar to be excreted. Once excreted, these are no longer available to build more cholesterol. Also cellulose remains undigested but is effectively making one gain more calories, so it helps prevents over eating.
Someone help me plz. I have no idea.
Answer:
fault im pretty sure
Explanation:
Answer:
fault............
...........
What is the root of all electrical systems?
1 batteries
2 electrons
3 atoms
4 non of the above
Answer:
I believe it's 2. I am not sure though.
HELP!! WILL MARK BRAINLIEST!!!!!
Complete the following sentences. Energy is required to _______ bonds in a molecule and released when bonds are _______.
Answer:
Create
Broken
Explanation:
Bond formation or creation requires the use of energy. Energy is used during bond formation between chemical species. The energy is required for the reaction to occur.
When bonds are broken, energy is releasedBond breaking process is a procedure that releases energy. This energy makes them able to react.what are the 5 destructive tests used in fiber analysis
How does the observed pitch of the buzzer change as it moves
observer?
pitch of the buzzer increased (higher tone) as it moves towards the observer
The pitch of the buzzer decreased (lower tone) as it moves towards the observer
The pitch of the buzzer stayed the same no matter where it was in relationship
to the observer
The answer is
Pitch of the buzzer increased (higher tone) as it moves towards the observer
The correct option that explains the change in the observed pitch of the buzzer as it moves towards the observer is;
A; pitch of the buzzer increased (higher tone) as it moves towards the observer
This is based on the concept of doppler effect which is defined as the change in frequency/pitch of a sound that is heard by an observer due to the fact that the sound source and the observer have different velocities with respect to the medium through the sound travels.Now, according to doppler effect, when the source of the sound moves towards the observer, the frequency will increase due to the fact that the time between successive sound waves is shortened. Thus, this means that the pitch will be higher. However, when the sound source moves away from the observer, the frequency would decrease due to the fact that the time between successive sound waves or the crest is now longer. Thus, the pitch will decrease.In conclusion, the pitch of the buzzer will increase as it moves towards the observer.
Read more at; https://brainly.com/question/3826119
What happens to the minerals as gneiss forms from schist?
Answer:
Explanation:
Gneiss is a high grade metamorphic rock, meaning that it has been subjected to higher temperatures and pressures than schist. However, unlike slate and schist, gneiss does not preferentially break along planes of foliation because less than 50% of the minerals formed during the metamorphism are aligned in thin layers.
PLEASE HELP! thxssss
Answer:
D is correct
Explanation:
NEED ASAP!! 23 POINTS!! Look at the pic above and tell me the velocity, distance and time. Thanks!
Answer:
Vp = 66.67 [mi/h]
Explanation:
To solve this type of problem we must remember that speed is defined as the relationship of space between time.
speed = distance/time
7)
v = speed = 100 [km/h]
distance = 750 [km]
time = distance/speed
time = 750/100
t = 7.5 [h]
8)
v1 = 200/3 = 66.67[mi/h]
v2 = 100/1.5 = 66.67 [mi/h]
Vp = average speed = (v1+v2/2)
Vp = (66.67 + 66.67)/2
Vp = 66.67 [mi/h]
answer is 9 Billion due to the decrease in Cactus
i really need help with this
Answer:
The Moon
Explanation:
F=MA
160=98a
a=1.632563061m/s²
This value is closest to the Moon's value
What is the specific heat of a substance that absorbs 2500 joules of heat when a sample of 100 g of the substance increases in temperature from 10 degrees Celsius to 70 degrees Celsius?
Answer:
I'm sorry to inform that I couldn't find an answer to this question. Socratic can help! This learning app, powered by Google AI, helps you understand your school work at a high school and university level. Ask Socratic a question and the app will find the best online resources for you to learn the concepts.
Explanation:
1. Three vehicles are traveling at the same speed in the same direction on a 1 point
highway, as shown in the diagram below. If the position of the front of the
white van is -21 m, what is the point of reference?
9514 1404 393
Answer:
The front of the black car
Explanation:
The position -21 is shown on the diagram at the front of the white van. The reference point is the position 0, which is shown on the diagram as the front of the black car.
Answer:
Explanation:
I'm answering this just so you can give the Brainliest to Squaredancefan, a master answerer in my opinion.
The reference point is where the 0 is. Everything to the right is positive and everything left of 0 is minus. 0 is the reference point because it is neither.
Plz help plllzzzzzzzz
Iron filings were sprinkled around these two magnets. What do the iron filings
show?
O A. They show that magnetic field lines point away from the north
pole of magnets.
B. They show the pattern made by the magnetic field lines around the
magnets
C. they show that magnetic field lines often cross over each other when magnets repel
D. they show the locations of the magnetic domains in the magnets
please help no ones questions match mine!!!
Answer:
B. They show the pattern made by the magnetic field lines around the
magnets
Explanation:
Using iron fillings, the pattern of the magnetic field lines around a bar magnet can be known.
Magnetic field lines are the line of force around a bar magnet.
These iron fillings will trace the pattern of the magnetic field around the magnet. The domains of the iron fillings begins to align and orient with that of the prevailing magnetic field around. Those areas with the strongest force will attract more fillings and those far away will attract lesser fillings.Answer:
B
Explanation: E Z
________ is the speed and direction of an object
Answer:
velocity
Explanation:
plz mark brainliestʕ•ᴥ•ʔ
a car is traveling at 30 metres per second it accelerates steadily for 5 seconds after which it is travelling at 50 metres per second calculate its acceleration
Answer:
its alot
Explanation:
What is the Net Force acting
on the box below?
A fighter jet flies 3 km west and then 2 km east in 8 minutes. Determine the jet's average velocity. (Remember to convert!)
Answer:
7.69km/hr due east
Explanation:
Given parameters:
Displacement due west = 3km
Displacement due east = 2km
Time taken = 8 minutes
Unknown:
Average velocity = ?
Solution:
Average velocity is the rate of change of displacement with time.
Velocity = [tex]\frac{displacement}{time }[/tex]
Displacement is deals with the start and the end;
Here, displacement = 3km - 2km = 1km due east
Time = 8min
60min = 1hr
8min = [tex]\frac{8}{60}[/tex] = 0.13hr
Average velocity = [tex]\frac{1km}{0.13hr}[/tex] = 7.69km/hr due east
GOOD MFRNING
PAGE NO.:
DATE:
cap a b
body have larger mess be holter than another of smaller
maws if they are same temperature why,
at the
Answer:
umm im confused
Explanation:
Answer:
larger mass more the molecule more heat absorbed
and vice versa .Thats the reason ok?
1. Some penguins are playing turtle hockey on the frictionless ice. Ramona the penguin hits the turtle
with a force of magnitude F, and the turtle experiences an acceleration of magnitude a (Fand a are of
unknown size). Francisco the penguin hits the same turtle with a force of magnitude three times
greater than Ramona's force (3F). What will the resulting acceleration of the turtle be? Answer in
terms of a. Support your answer with reasoning and reference to Newton's Second Law.
Answer:
a' = 3a
Explanation:
Newton's Second Law gives the magnitude of the unbalanced force applied to an object as follows:
F = ma
where,
F = Force Applied
m = Mass of Object
a = acceleration
FOR RAMONA'S PUSH:
F = F
m = m
a = a
Therefore,
F = ma
a = F/m ---------------- equation (1)
FOR FRANSICO'S PUSH:
F = 3F
m = m (mass of turtle will be same)
a = a'
Therefore,
3F = ma'
a' = 3F/m
using equation 1
a' = 3a