Answer:
1040
Explanation:
The rules for significant digits is that non-zero digits are significant figures. The zero in between 1 and 4 is significant because any zeroes between two significant digits are significant. Trailing zeroes if there is no decimal point are insignificant.
The number 1045.2 rounded to three significant digits would be 1040 because the rightmost zero is not a significant digit.
What are significant figures?In positional notation, significant figures refer to the digits in a number that is trustworthy and required to denote the amount of something, also known as the significant digits, precision, or resolution.
The definition of a significant digit according to the criteria is a non-zero digit. Any zeroes between two significant digits, such as the one between 1 and 4, are noteworthy. In the absence of a decimal point, trailing zeroes are not relevant.
According to the criteria for significant digits, non-zero digits are important numbers. The zero between 1 and 4 is crucial, as is any zero between two significant digits. The trailing zeroes are irrelevant if there is no decimal point.
Thus, the number 1045.2 rounded to three significant digits would be 1040.
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I need help with this question below ASAP!
A net force of 400 N is exerted on an object. Its vector speed goes from 66 km / h to 30 km / h in 2.5 s. a) What is the acceleration of this object? B) What is its mass?
Thank you for your help :)
Answer:
Mass M = 100 kg
Explanation:
Given;
Net force = 400 N
Initial velocity u = 66 km/h
Final velocity v = 30 km / h
Time taken = 2.5second
Find:
Acceleration of this object a
Mass M
Computation:
1 km/h = 0.277778 m/s
So,
Initial velocity u = 66 km/h = 18.333
Final velocity v = 30 km / h = 8.333
Acceleration of this object a = [v - u]/t
Acceleration of this object a = [8.333 - 18.333]/2.5
Acceleration of this object a = -4 m/s²
Mass M = Force / Acceleration of this object a
Mass M = 400 / 4
Mass M = 100 kg
Imagine a landing craft approaching the surface of Callisto, one of Jupiter's moons. If the engine provides an upward force (thrust) of 3456 N, the craft descends at constant speed; if the engine provides only 2333 N, the craft accelerates downward at 0.39 m/s2. What is the weight of the landing craft in the vicinity of Callisto's surface
Answer:
[tex]W=3456 N[/tex]
Explanation:
Force 1 [tex]F_1=3456[/tex]
Force 2 [tex]F_2=2333N[/tex]
Acceleration at stage 2 [tex]a_2=0.39[/tex]
Generally the weight of the Craft W is given as
W= upward force(thrust)
Therefore
[tex]W=3456 N[/tex]
What would be the electric field (magnitude and direction) of 1.50 cm to the right of a charge of -6.5 × 10-6 C?
Answer:
Explanation:
The formula for the electric field is
[tex]E=\frac{kQ}{r^2}[/tex] where E is the magnitude of the electric field, k is Coulomb's constant, Q is the charge of the particle (which is NOT included in the formula), and r is the distance between the centers of the charges (for lack of a better description).
[tex]E=\frac{(9.0*10^9)*(6.5*10^{-6})}{(1.50)^2}[/tex] and we get, to 2 sig fig's
E = 2.6 × 10⁴ to the left (since electric fields are always pointing toward the negative charge and the electric field is to the right of the negative charge)
Define SI unit of measurement.
Answer:
the group of units suggested by the international convention of scientists in 1960 AD to make similarties in meseurment all over the world is called SI units
An ice-skater with a mass of 80kg is holding a bowling ball with a mass of 8 kg. Suppose that the skater tosses the bowling ball forward with a speed of 6 m/s. What is the skater's reactive velocity? Show all work.
Answer:
0.6 m/s
Explanation:
The details of the masses and velocities are;
The mass of the ice skater, m₁ = 80 kg
The mass of the ball, m₂ = 8 kg
The speed with which the skater tosses the ball forward, v₂ = 6 m/s
Therefore;
According to the principle of conservation of linear momentum, we have;
m₁·v₁ = m₂·v₂
Where;
v₁ = The skater's reactive velocity
Therefore, we get;
80 kg × v₁ = 8 kg × 6 m/s
v₁ = 8 kg × 6 m/s/(80 kg) = 0.6 m/s
The skater's reactive velocity, v₁ = 0.6 m/s.
What uses non-renewable energy?
A)a gematrical heating system
B)a nuclear power station
C)a solar panel
D)a wind turbine
Uma pilha AA (pilha de controle remoto) fornece ao circuito 1,5V, já uma bateria de carro fornece 12V. Qual a relação entre a energia fornecida entre esses elementos de circuito?
Answer:
The ratio of energy of AA battery to the car battery is 0.0156.
Explanation:
An AA battery (remote control battery) supplies the circuit with 1.5V, while a car battery supplies 12V. What is the relationship between the energy supplied between these circuit elements?
Supply by AA battery = 1.5 V
Supply by car battery = 12 V
The resistance of the circuit is R.
The energy supplied = V^2/R
The energy supplied by the AA battery is
E = 1.5 x 1.5 / R = 2.25/R
The energy supplied by the car battery is
E' = 12 x 12/ R = 144 / R
So, the ratio of
E : E' = 2.25 : 144 = 0.0156
I need help with this question below ASAP!
What is the acceleration when an unbalanced force of 55 N is exerted on a 40 kg person?
Thank you for your help :)
Answer:
a = 1.375m/s²
Explanation:
F = m*a
55N = 40kg*a
a = 55N/40kg
a = 1.375m/s²
In which phase(s) of matter are the atoms closely packed but still able to slide past each other? O gas O liquid O solid and gas O liquid and solid Save and Exit Next Summit Mark this and return
Answer:
Liquid
Explanation:
In most liquids the particles are less densely packed giving them the ability to move around and slide past each other.
What conditions can impact the ecological tolerance of a species?
Pls Answer,30 points
Answer:
climatic changes
ambient changes
human interferance and the growt of cities and human civilization
and invasive especies
Explanation:
Many different physical factors can impact the ecological tolerance of a species like:-
temperature humidity soil chemistry pHsalinity oxygen levelsHow physical factors impact the ecological tolerance of a species?Climatic factors such as temperature and precipitation are key drivers to control species distribution directly.Topographic features such as slope and elevation can impact local climate as well as soil conditions that in turn have varied effects on vegetation structure.The relative distance from a water source can also affect the composition and distribution of woody vegetation because of the resulting varying amount of water available for growth. Physical and chemical soil properties can inform vegetation patterns on a local scale.What is a tolerance range?The portion of the abiotic factor's range of variation which a species can survive and function in is commonly defined as the tolerance range.
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Which wave has the largest amplitude?
A.D
B.B
C.C
D.A
Answer:
D. A
General Formulas and Concepts:
Simple Harmonic Motion
Parts of a wave
PeriodAmplitudeWavelengthCrest/TroughExplanation:
The amplitude is the distance from the horizon to either the crest or trough of a wave.
In layman's terms, it is how high the wave is.
The "highest" wave would be wave A.
∴ our answer is D.
Topic: AP Physics 1 Algebra-Based
Unit: SMH
Answer:
A (The wave)
Explanation:
Wave A
Room heaters are placed on the floor of a room; Give reason:
Room heaters are placed on the floor of a room so that the air heated by it rises up and sets up the convection current in the room quickly and uniformly.
You are trying to hold your 550 g physics books with your hand against a vertical wall. Using a force sensor you know that the force you are applying is 10.0 N. Below the book on the floor you have placed a motion sensor. The position time graph for the book is given. Find the coefficient of kinetic friction.
The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is
∑ F = 10.0 N - n = 0
where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is
∑ F = f - (0.550 kg) g = 0
where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.
Then
• n = 10.0 N
• f = (0.550 kg) g = 5.39 N
• 5.39 N = µ (10.0 N)
==> µ = 0.539
Answer:
Above answer
Explanation:
The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is
∑ F = 10.0 N - n = 0
where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is
∑ F = f - (0.550 kg) g = 0
where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.
Then
• n = 10.0 N
• f = (0.550 kg) g = 5.39 N
• 5.39 N = µ (10.0 N)
==> µ = 0.539
Which symbol and unit of measurement are used for electric current?
symbol. A, unit: 1
symbol: C, unit: A
symbol l; unit C
symbol: 1; unitA
Answer: Symbol is I and unit A
Explanation: A represents Amperes
HOPE THIS HELPS!!!!!!!!
The moon is 3x10^5 km away from Nepal and the mass of the moon is 7x10^22 kg. Calculate the force with which the Moon pulls every kilogram of water in our rivers.
Answer:
Approximately [tex]5.19 \times 10^{-5}\; \rm N[/tex].
Explanation:
Let [tex]G[/tex] denote the gravitational constant. ([tex]G \approx 6.67 \times 10^{-11} \; \rm N \cdot kg^{-2} \cdot m^{2}[/tex].)
Let [tex]M[/tex] and [tex]m[/tex] denote the mass of two objects separated by [tex]r[/tex].
By Newton's Law of Universal Gravitation, the gravitational attraction between these two objects would measure:
[tex]\displaystyle F = \frac{G \cdot M \cdot m}{r^{2}}[/tex].
In this question: [tex]M = 7 \times 10^{22}\; \rm kg[/tex] is the mass of the moon, while [tex]m = 1\; \rm kg[/tex] is the mass of the water. The two are [tex]r = 3\times 10^{5}\; \rm km[/tex] apart from one another.
Important: convert the unit of [tex]r[/tex] to standard units (meters, not kilometers) to reflect the unit of the gravitational constant [tex]G[/tex].
[tex]\displaystyle r = 3 \times 10^{5}\; \rm km \times \frac{10^{3}\; \rm m}{1\; \rm km} = 3 \times 10^{8}\; \rm m[/tex].
[tex]\begin{aligned} F &= \frac{G \cdot M \cdot m}{r^{2}} \\ &= \frac{6.67 \times 10^{-11}\; \rm N \cdot kg^{-2}\cdot m^{2} \times 7 \times 10^{22}\; \rm kg \times 1\; \rm kg}{(3 \times 10^{8}\; \rm m)^{2}} \\ &\approx 5.19 \times 10^{-5} \; \rm N\end{aligned}[/tex].
WhAT is the change IN THE entropy of 2.0kg of h2o molecules when transform at a constant pressure of 1 atm from water at 100 degrees celcius to steam at the same tEMPERATURE?
Answer:
The entropy change is 45.2 kJ/K.
Explanation:
mass of water at 100 C = 2 kg
Latent heat of vaporization, L = 2260 kJ/kg
Heat is
H = m L
H = 2 x 2260 = 4520 kJ
Entropy is given by
S = H/T = 4520/100 = 45.2 kJ/K
The entropy change during the phase change of water from liquids to steam at constant pressure and same temperatures will be zero because, Δ T is zero here.
What is entropy?Entropy is a thermodynamic parameter determining the measure of randomness in a system. Entropy of a natural reaction or change is always increasing.
According to second third law of thermodynamics the entropy change of the universe is positive always. At constant pressure the entropy change a of substance of m g is written as:
ΔS = m Cp ln T2/T1.
Where Cp is the specific heat capacity at constant pressure.
Here, the initial temperature and final temperature is same 100 degree celsius. Thus T2/T1 becomes 1 and log 1 is zero. Therefore, the entropy change in this phase change is zero.
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Pluto has a shape that is nearly round,and it orbits the sun,it has five known moons.why is it called a dwarf planet and not a planet?
There are three things needed to be classified as a planet.
Pluto meets 2 of the 3.
The one it does not meet is it doesn’t “clear the neighborhood” which means a planet needs to be gravitationally dominant over all objects around it. Meaning smaller bodies ( asteroids) would either combine with the larger body making it bigger or pushing them away ( out of their orbit) so they do not collide with the larger body.
A stone is thrown vertically upwards with an initial velocity of 20m/sec. Find the maximum height ot reaches and the time taken by it to reach the height. (g=10m/s2)
plz short numerical ASAP
Answer:
The height reached is 20m, The time taken to reach 20m is 2 seconds
Explanation:
Observing the equations of motion we can see that the following equation will be most helpful for this question.
[tex]v^{2} = u^{2} + 2as[/tex]
We are given initial velocity, u
We know that the stone will stop at its maximum height, so final velocity, v
Acceleration, a
And we are looking for the displacement (height reached), s
Substitute the values we are given into the equation
[tex]0^{2} = 20^{2} + 2(10)s[/tex]
Rearrange for s
[tex]0^{2} -20^{2} =20s[/tex]
[tex]-400=20s[/tex]
[tex]\frac{-400}{20} =s[/tex]
s = -20 (The negative is just showing direction, it can be ignored for now)
The height reached is 20m
Use a different equation to find the time taken
[tex]s = vt - \frac{1}{2} at^{2}[/tex]
Substitute in the values we have
[tex]-20=(0)t - \frac{1}{2} (10)t^{2}[/tex]
Rearrange for t
[tex]-20 =0 -5 t^{2}[/tex]
[tex]\frac{-20}{-5} =t^{2}[/tex]
[tex]4 = t^{2}[/tex]
t = 2s
The time taken to reach 20m is 2 seconds
If the man pushes with a force of 2000N and friction is 500N, what is the resultant force?
Answer:
Explanation:
If the force of 2000 N is directed towards the right and the friction is directed towards the left, the 2000 N force is positive and the other is negative. To find the resultant force:
2000 - 500 = 1500 N to the right
the internal resistance of each of the following cells E1 and E2 shown in the figure above is 2ohms. calculate the total current in the circuit
Answer:
The total current in the circuit is 0.8 A.
Explanation:
internal resistance of each battery = 2 ohm
Total emf of the circuit, E = E1 + E2 = 2 = 2 = 4 V
Now total internal resistance is
[tex]r = \frac{2\times 2}{2 + 2}= 1 ohm[/tex]
Total resistance, R = 4 = 1 = 5 ohm
Let the current is I.
E = I R
4 = I x 5
I = 0.8 A
1.the student measures the mass of a piece of metal.its mass is 146g.
(a) the volume of the piece of metal is 20cmcube. calculate the density of the metal .
(b) state the unit.
Answer:
7.3 g/cubic cm
Explanation:
You divide the mass by the volume to calculate the density of the metal.
146g ÷ 20cm³ = 7.3g/cm³
please answer me my question
A 17Kg sitting on a shelf has a potential energy of 350J. How high is the shelf? Round your number to the nearest whole number
Answer:
[tex]{ \bf{potential \: energy = mass \times gravitation \times height}} \\ 350 = 17 \times 10 \times h \\ 350 = 170h \\ height = 2.06 \: metres[/tex]
the direction of applied force has to be_____ to the distance in order to say work is done
Answer:
Explanation:
The direction of the applied force has to be parallel to the distance an object moved in order to say that work has been done.
In which condition is relative velocity known by adding the velocity od the first body and that of the second body ?
Answer:
when a two bodies A and B are moving at an angle 180° with each other then the relative velocity is the sum of bodies the velocity .i.e,
when the bodies move the opposite direction
then their relative velocity is the sum of individual velocities.
what is the answer to the question in the picture?
Answer:
yes,
Explanation:
because a compound contains two or more chemical elements chemically bond together.
5. According to the law of reflection, the
is equal to the angle of incidence and a line drawn perpendicular to the reflecting surface.
O reflected ray
angle of reflection
O angle of refraction
Answer:
the answer is ....angle of reflection
Kevin used a pulley to lift a piano to the third floor of his apartment. His input work was 12,000 J and the output work was 10,000 J. What was the mechanical efficiency of the pulley?
A . 50%
B. 83.3%
C . 120%
D. 16.7%
Answer:
B
Explanation:
Eff = output work/input work ×100
Hence, Eff = 10000/12000 × 100
Eff = 83.3%
Chiếu tia sáng lên một gương phẳng biết góc tới bằng 15⁰ hãy tính góc phản xạ bằng bao nhiêu
Answer:
góc phản xạ 15°
Explanatin
The force of gravitation between two cricket balls is extremly small but that between a cricket ball and earth is extremly is large?
Explanation:
Gravitational force depends upon the product of masses of the object. Earth has siginificantly greater mass than cricket ball. The product of masses for two ball is very low as compared to the product of earth and ball mass. That is why the gravitational force between earth and ball is relatively larger than two balls.
Answer:
The force of gravitation between the earth and the ball is large than the two balls.
Explanation:
The force of gravitation between the two bodies is directly proportional to the product of masses of two bodies and inversely proportional to the square of the distance between them.
So, when we take cricket balls , the masses of balls is very small and the distance is also small so the force between the two balls is small.
When we take earth and the ball, the mass of earth is very large eve distance is very large so the force between the earth and the ball is large as compared to the two balls.
