Answer:
I don't know sorry' please
round off 20.96 to 3 significant figures. a.20.9 b.20 c.21.0 d.21
Answer:
option c. 21.0
Explanation:
It was given that to find 3 significant figures. So the answer is 21.0
7) A ball is thrown upward at an initial velocity of 8.2 m/s, from a height of 1.8 meters above the ground. The height of the ball h, in metres can be represented, after t seconds, is modelled by the equation h = –4.8t² + 8.2t + 1.8. (a) Determine the height of the ball after 1.7 seconds.
Answer:
8392
Explanation:
d=s/t
determjne the density of liquid whose relative density is 1.25 given that the density is 1000kgm-3
Answer:
divide the density of solution by density of water
EXPLANATION:
LIKE:
1.25÷1000kgm-3
Using your Periodic Table, which of the elements below is most likely to be a solid at room temperature?
A.) potassium, B.) Hydrogen, C.) Neon, D.) Chlorine
The answer is definitely Potassium
Question in the picture please help me...
Show all steps please....
Answer: i)A to B : (ice) freezing
ii) B to C (water) boiling
C to D (steam) evaporating
explanation: 0° is the freezing point of water when temperature increases from 0° the water starts melting. As 100° is the boiling point of water so at 100° the water completely melts and it starts boiling during boiling water changes into steam(water vapour) and it evaporates
An element is highly conductive, highly reactive, soft, and lustrous. The element most likely belongs to which group?(1 point)
transition metals
noble gases
metalloids
alkali metals
Answer:
Alkali metals
Explanation:
Elements in this group are highly reactive, soft, lustrous and highly conductive.
An element which is highly conductive, highly reactive, soft, and lustrous is most likely an alkali metal.
Alkali metals are in group 1 of the Periodic table which means that they have only a single valence electron.
This causes them to be soft and highly reactive because:
The single valance electron leads to weak bonds amongst the element's atoms which makes them softThe elements want to lose the single valance electron so as to become stable so they will react with other elements to give away the electron.Examples of alkali electrons include:
Lithium Sodium Potassium etcIn conclusion therefore, alkali metals are highly reactive and soft and so the element described above is most likely an alkali metal.
Find out more at https://brainly.com/question/18722874.
4. When setting goals, you should do everything EXCEPT which of the following?
Take into account your current level of activity.
Ask all of your friends what they think your goals should be..
Set a time limit.
Be realistic.
If 20N force produces an acceleration of 5ms^-2 In a body then the mass of the body will be:
A.4kg
B.5kg
C.1/4kg
D.1/5kg
15millas a km alguien pliss para ahorita porfa lo sigo
Answer:
X = 24.135 kilometres
Explanation:
Given the following data;
Distance = 15 miles
To convert the value in miles to kilometers;
Conversion:
1 mile = 1.609 kilometres
15 miles = X kilometres
Cross-multiplying, we have;
X = 1.609 * 15
X = 24.135 kilometres
what is efficiency of a machine?
Answer:
Efficiency of a machine is defined as the ratio of output work to input work in a machine . It is expressed in percentage and denoted by
η ( eta).
direct or indirect
"Susan is a lovely ten-year-old girl from Hawaii."
Answer:
Direct
Explanation:
PRESS THE PHOTO NEED HELP!!! 30 POINTS
1:-
[tex]\\ \sf\longmapsto cos\Theta=\dfrac{B}{H}[/tex]
[tex]\\ \sf\longmapsto cos\Theta=\dfrac{4}{5}[/tex]
2:-
[tex]\\ \sf\longmapsto tan\Theta=\dfrac{P}{B}[/tex]
[tex]\\ \sf\longmapsto Tan\Theta=\dfrac{3}{4}[/tex]
Key Notes:-
P denotes to Perpendicular.B denotes to Base.H denotes to Hypotenuse.Answer:
Cos A = 4/5
Tan A = 3/4
Explanation:
Cos A = Adjacent/Hypotenuse = 4/5
Tan A = Opposite/Adjacent = 3/4
Can someone do this for the football
Estimated volume
(cm3)
Estimated density
(g/cm3)
edge.
Answer:
0.10 g/cm3
TRUST ME GUYS
can anyone help me to explain theory of relativity???
Answer:
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.
The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves
Can someone pls help, thank you in advance!
What is an example of a force applied at an angle to displacement
Answer:
an object sliding down hill
Explanation:
On a slope, the force applied is due to gravity. Its direction is straight down. If the object is sliding down the hill, its displacement is at an angle to the applied force. The angle of displacement will depend on the steepness of the hill.
Angie walked a distance of 90 meters east in 70 seconds. What was her
velocity?
A. 0.78 m/s east
B. 1.3 m/s east
O C. 7 m/s east
D. 9 m/s east
Động vật nào sau đây máu đi nuôi cơ thể không pha trộn giữa máu giàu O2 và máu giàu CO2?
A.
Bò sát, chim, thú
B.
Cá, bò sát, chim
C.
Cá, lưỡng cư, bò sát
D.
Cá, chim, thú
Answer:
D
Explanation:
Cá xương, chim, thú, cá sấu không có sự pha trộn máu giàu O2 và máu giàu CO2 ở tim vì tim cá có 2 ngăn, tim các loài chim, thú, cá sấu có 4 ngăn
A cyclist goes round a circular path of circumference 343 m in s. The angle made by him, with the vertical is
WITH STEPS PLZ
you need the number of seconds to calculate the distance. I'm assuming that the seconds were written in the question but you forgot to write the here, you can calculate the distance then and find the exact point where the cyclist stopped since you have the circumference. then you can find the angle (after finding the distance he cycled) by subtracting it from 360 since the circular path will have an angle of 360 degrees.
Although your question lacks some data A general answer is provided :
The angle made vertically = 360° - x°
where x = angle at which the the cyclist stopped
and circumference of the circular path = Total Distance travelled by the cyclist
First step : determine the distance travelled by the cyclist vertically
circumference = 2*π*r
343 = 2*π * r
∴ r = 343 / ( 2π ) = 54.59
therefore distance travelled by the cyclist vertically = 54.59 * 2 = 109.18 m
Given that the time travelled is missing
assuming the angle to the distance travelled by the cyclist before it stopped vertically = 360° - x°
This is because the Total angle of a circular path = 360°
Learn more about circular paths : https://brainly.com/question/24210487
A block of amber is placed in water and a laser beam travels from the water through the amber. The angle of incidence is 35 degrees while the angle of refraction is 24 degrees. What is the index of refraction of amber?
(index of refraction of water is 1.33)
1. A bicycle initially moving with a velocity
5.0 m s-1 accelerates for 5 s at a rate of 2 m s? Wh
will be its final velocity ?
Answer:
[tex]\boxed {\boxed {\sf 15 \ m/s \ or \ 15 \ m*s^{-1}}}[/tex]
Explanation:
We are asked to find the final velocity. We are given the acceleration, time, and initial velocity, so we can use the following kinematics formula.
[tex]v_f= v_i+ at[/tex]
In this formula, [tex]v_f[/tex] is the final velocity, [tex]v_i[/tex] is the initial velocity, [tex]a[/tex] is the acceleration, and [tex]t[/tex] is the time.
The bicycle has an initial velocity of 5.0 m *s⁻¹ or m/s, acceleration of 2 m/s², and a time of 5 seconds.
[tex]\bullet \ v_i = 5.0 \ m/s \\\bullet \ a= 2\ m/s^2\\\bullet \ t= 5 \ s[/tex]
Substitute the values into the formula.
[tex]v_f=5.0 \ m/s + ( 2\ m/s^2 * 5 \ s)[/tex]
Solve inside the parentheses.
[tex]\frac {2 \ m}{s^2}* 5 \ s = \frac{ 2 \ m}{s} * 5 = \frac{ 10 \ m}{s} = 10 \ m/s[/tex][tex]v_f= 5.0 \ m/s + (10 \ m/s)[/tex]
Add.
[tex]v_f= 15 \ m/s[/tex]
The units can also be written as:
[tex]v_f= 15 \ m*s^{-1}[/tex]
The bicycle's final velocity is 15 meters per second.
A lady walks 10 m to the north, then she turns and continues walking 30 m due east.
Determine her(a) distance covered
(b) displacement.
Answer:
The distance covered is 40 m and the displacement is 31,6m.
Explanation:
The distance covered is the sum of the two distances (10+30). The displacement is equal to the distance of the hipotenusa of the triangle that the two distances (10 m to north and 30m to east) create. Using the Pythagoras theorem the displacent is equal to the Square root of (30^2 +10^2) .
You observe that you see more mockingbirds in small trees and more hawks in large trees. Which of the following is an appropriate scientific question based on this observation?
How does the size of a tree affect the bird species that prefer to live in it?
How do birds fly?
What type of food do birds eat?
What time of year to birds mate?
Answer:
A) How the size of a tree affect the bird species that prefer to live in it
Explanation:
I took the quiz
An oscillator completes 240 cycles in 5.2 minutes.
Calculate its period (in seconds) and frequency (in Hz).
Answer:
I. Period = 1.3 seconds
II. Frequency = 0.769 Hertz
Explanation:
Given the following data;
Number of oscillation = 240 cycles
Time = 5.2 minutes.
Conversion:
1 minute = 60 seconds
5.2 minutes = X seconds
X = 60 * 5.2
X = 312 seconds
To find the following;
I. Period
Mathematically, the number of oscillation of a pendulum is given by the formula;
[tex] Number \; of \; oscillation = \frac {Time}{Period} [/tex]
Making period the subject of formula, we have;
[tex] Period = \frac {Time}{Number \; of \; oscillation} [/tex]
Substituting into the formula, we have;
[tex] Period = \frac {312}{240} [/tex]
Period = 1.3 seconds
II. Frequency
[tex] Frequency = \frac {1}{Period} [/tex]
Substituting the values into the formula, we have;
[tex] Frequency = \frac {1}{1.3} [/tex]
Frequency = 0.769 Hertz
Lúc 7g bạn an đi từ nhà đến trường với tóc độ trung bình là 20km/h . Bạn đến trường lúc 7g20. Tính khoảng cách từ nhà tới trường?
Answer:
Distance = 6.667 kilometres
Explanation:
Given the following data;
Speed = 20 km/h
Departure time = 7:00
Arrival time = 7:20
Time taken = 20 minutes
To calculate the distance travelled from home to school;
First of all, we would have to convert the value of time in minutes to hours.
Conversion:
60 minutes = 1 hour
20 minutes = X hours
Cross-multiplying, we have;
X = 20/60 = 1/3 hours
Mathematically, the distance travelled by an object is calculated by using the formula;
Distance = speed * time
Distance = 20 * 1/3
Distance = 20/3 =
Distance = 6.667 kilometres
Why are road accidents at high speeds very much worse than road accidents at low speeds?
Answer:
The momentum makes it worse.
Explanation:
The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.
this is physics practical
Answer:
well done buddy
Explanation:
Có một số điện trở giống nhau R0 = 3
. Cần ít nhất bao nhiêu điện trở để có một
đoạn mạch có điện trở Rtđ = 8
Answer:
hlo
Explanation:
hlo olz mark me as brainlest
if A vector = i^-j^+k^ then unit vector in the direction of A vector
a)√3,j^
b)(i^-j^+k^)
c)(i^-j^-k^)/√2
d)(i^-j^+k^)/√3
plzz answer my question with explanation
If A = i - j + k, then the magnitude of A is
||A|| = √(1² + (-1)² + 1²) = √3
Then the unit vector in the direction of A is 1/||A|| multiplied by A :
u = A/||A|| = (i - j + k)/√3
(choice D)
Using your Periodic Table, which element below has the smallest atomic radius? A.) Sodium, B.) Chlorine, C.) Phosphorus, D.) Iron
Chlorine has the smallest atomic radius since the atomic radius decreases as you travel to the right and up
Sort the processes based on the type of energy transfer they involve. condensation freezing deposition sublimation evaporation melting thermal energy added thermal energy removed
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
Explanation:
Thermal energy is heat energy. Processes in which heat is added involve the addition of thermal energy while processes in which heat energy is removed involves removal of thermal energy.
Condensation involves a change from gas to liquid, freezing involves a change from liquid to solid while deposition involves the settling of mobile particles at a place. All these processes involve a decrease in energy of particles.
On the other hand, sublimation is a direct change from solid to gas, melting involves a change from solid to liquid while evaporation involves a change from liquid to gas. All these processes occur when energy is added to the particles in a system.
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
