Answers
Answer:
(D) 4×10⁻³
Explanation:
The difference is ...
0.2050 -0.2014 = 0.0036 = 3.6×10⁻³
The number 0.205 is expressed to a precision of 1×10⁻³, so the result of the subtraction operation cannot be considered to be more precise. It must be expressed as ...
4×10⁻³ . . . . matches choice D
_____
Additional comment
This is physics, not math. In the physical sciences, most numbers must be considered to be measurements. (A few are definitions.) Hence, the rules of significant figures and precision apply to the results of arithmetic operations. This problem is a good illustration of what happens when computing small differences of large numbers. We start with 3 significant figures in 0.205, and end up with 1 significant figure in 0.004.
Related Questions
A 500-kg crate sits on a 10-degree ramp. If friction between the ramp and the crate is 800 N, what is the acceleration of the crate?
Answers
By Newton's second law, the net force acting on the crate parallel to the surface is
∑ F = mg sin(10°) - 800 N = ma
where m = 500 kg is the mass of the crate and a is the acceleration.
Solve for a :
a = ((500 kg) (9.80 m/s^2) sin(10°) - 800 N) / (500 kg)
a ≈ 0.102 m/s^2
Which of the following is not a true statement
Answers
Answer:
gadjgdasgdghgsdgd
Explanation:sorry need answer
Answer:
V * t = cm/sec * sec = cm
V * t should give distance as a result -
The other three fit the fundamental equations
3- Define light year. What quantity does it measure? what is one light year equal to in sl unit?
Answers
Astronomical units: 63241 au; 0.3066 pc
Metric (SI) units: 9.4607×1015 m; 9.46075 Pm
Imperial & US units: 5.8786×1012 mi
Select the correct answer.
Which quantity is a vector quantity?
ОА. .
acceleration
OB.
mass
OC.
speed
O D.
volume
Reset
Next
Answers
Answer:
acceleration is the vector quantity because it depends on particular direction and has magnitude
6. A warehouse employee is pushing a 15.0 kg desk across a floor at a constant speed of 0.50 m/s. How much work must the employee do on the desk to change the speed to 1.00 m/s?
Answers
Answer:
7.5 J
Explanation:
To answer the question given above, we need to determine the energy that will bring about the speed of 1 m/s. This can be obtained as follow:
Mass (m) = 15 Kg
Velocity (v) = 1 m/s
Energy (E) =?
E = ½mv²
E = ½ × 15 × 1²
E = ½ × 15 × 1
E = ½ × 15
E = 7.5 J
Therefore, to change the speed to 1 m/s, the employee must do a work of 7.5 J.
A machine has mechanical advantage 2.What does that mean
Answers
Answer:
Mechanical advantage is the measure of the force amplification achieved by using a tool , mechanical device or machine . The machine preserve the input power and supply trade off force. against movement to obtain a desired amplification in the output force .
Answer:
The ratio of load overcome by the machine to the effort applied is called mechanical advantage.
On which planet would your weight be the most and the least?
a) Jupiter and Mercury
b. Jupiter and neptune
c. Saturn and Neptune
d. Saturn and uranus
Answers
Answer:
Jupiter and neptune
Explanation:
Sean and Tommy are debating the positive and negative impacts of technology on environmental quality. Tommy is listing the negative impacts. Which of the following would help his argument?
A. Solar panels have become more effective due to technological improvements.
B. Technology has helped make recycling to be more efficient.
C. It has created new ways to clean up oil spills.
D. Factories contribute to air and water pollution
Answers
Gold at 100.0°C is placed in 2.00×10^2 g of water at 20.0°C. The mixture reaches equilibrium at 21.2°C. the specific heat of gold is 0.129 (J/g°C) What is the mass of the gold? Specific heat of water is 4.18 (J/g°C) .
Answers
Answer:
there it is fella atleast i tried
How many players are allowed to play for one team during a game of
5 points
Netball?
Answers
Answer:
Netball is a ball sport for two teams of seven players it's rules are published in print and online by the international netball federation Games are played on a rectangular court divided into thirds with a raised goal at coach short end
Explanation:
It will help you
skater with a mass of 50.0 kg slides across an icy
pond with negligible friction. As he approaches a
friend, both he and his friend hold out their hands,
and the friend exerts a force in the direction oppo-
site to the skater's movement, which slows the skat-
er's speed from 2.0 m/s to 1.0 m/s. What is the
change in the skater's kinetic energy?
A. –25 J
C. – 100J
B. -75J
D. -150J
Answers
Answer:
B
Explanation:
Calculate the kinetic energy before and after they hold hands. Then, to find the change in kinetic energy simply subtract the final KE by initial KE.
Explain: What happens to the velocity of a stream as the size of the sediment increases?
Answers
Answer:
Also, as stream depth increases, the hydraulic radius increases thereby making the stream more free flowing. Both of these factors lead to an increase in stream velocity. The increased velocity and the increased cross-sectional area mean that discharge increases.
The unit of area is a derived unit. Why?
Answers
Explanation:
area=length(m) ×breadth(m) . The unit of area is expressed in terms of fundamental units m^2.thus it is derived unit
A runner has a speed of 5 m/s and a mass of 130 kg. What is his kinetic
energy?
O A. 1625 J
B. 3250 J
C. 875 J
D. 325 J
Answers
Mass = 130kg
Speed = 5m/s
1/2 x 130 x 25
= 1625J
ball of mass M kg is dropped from rest off a high building and strikes the ground 10 seconds later. Calculate the height of the building assuming that upwards is positive in this coordinate system
Answers
Answer:
h = 1/2gt^2
Is the formula for the height of a free falling object.
Put in the numbers:
h = 1/2*9.8 (gravitational constant) * 10^2
h=490 meters.
Please note that the gravitational constant is approximate, you could also use a more specific value or 10
A HIGH SPEED TRAIN IS 180M LONG AND IT IS TRAVELLING AT 50M/S.HOW LONG WILL IT TAKE TO PASS A PERSON STANDING AT A LEVEL CROSSING?
B-HOW LONG WILL IT TAKE TO PASS COMPLETELY THROUGH A STATION WHOSE PLATFORMS ARE 220M IN LENGTH?
Answers
Answer:
a. Time = 3.6 seconds
b. Time = 4.4 seconds
Explanation:
Given the following data;
Distance = 180 m
Speed = 50 m/s
a. To find the time;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
[tex]Speed = \frac{distance}{time}[/tex]
Making time the subject of formula, we have;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{180}{50}[/tex]
Time = 3.6 seconds
b. Distance = 220 meters
Speed = 50 m/s
To find the time;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{220}{50}[/tex]
Time = 4.4 seconds
Which has greater kinetic energy, a car traveling at 40 mph or a half-as-massive car traveling at 80 mph?
a
-The 40 mph car
-The 80 mph car
-Both have the same kinetic energy
-Neither has kinetic energy
Answers
Answer:
The 80 mph car
Because the formula says 1/2 mass but for the velocity it is squared
calculate the volume of a ball having radius of 8 cm
Answers
Step-by-step explanation:
V = 2,143. 6 cm³ (rounded to one-decimal place) is the volume of a ball that has a radius of 8 cm.
Answer:
2143.57 cm^3
Explanation:
volume of a ball = 4/3 *π*r^3
= [tex]\frac{4}{3} *3.14 *8^{3}[/tex]
=[tex]\frac{4*3.14}{3} *512[/tex]
[tex]\frac{12.56}{3} *512[/tex]
=[tex]\frac{12.56*512}{3}[/tex]
=[tex]\frac{6430.72}{3}[/tex]
=2143.57
A runner is traveling with an initial velocity of 0.3 m/s in the positive direction accelerates at a constant rate of 0.4m/s^2 for a time of 2 seconds. What is the velocity at the end of 2 seconds?
Answers
Answer:
1.1 m/s
Explanation:
Applying,
v = u+at.............. Equation 1
Where v = final velocity, u = initial velocity, a = acceleration, t = time.
From the question,
Given: u = 0.3 ms, a = 0.4 m/s², t = 2 seconds
Substitute these values into equation 1
v = 0.3+0.4(2)
v = 0.3+0.8
v = 1.1 m/s
Hence the velocity at the end of 2 seconds is 1.1 m/s
Một vật có khối lượng 2 kg rơi tự do xuống đất trong khoảng thời gian 0,5 s. Độ biến thiên động lượng của vật trong khoảng thời gian đó là bao nhiêu ? Cho g = 10 m/s2.
Answers
Answer: The change in momentum is +20 kg.m/s
Explanation:
To calculate the final velocity of object, we use the first equation of motion:
[tex]v=u+at[/tex]
where,
v = final velocity
u = initial velocity = 0 m/s
a = acceleration = [tex]10m/s^2[/tex]
t = time = 0.5 s
Putting values in above equation, we get:
[tex]v=0+(10\times 0.5)\\\\v=5m/s[/tex]
Momentum is defined as the product of the mass and velocity of an object. It is given by the equation:
[tex]p=mv[/tex]
where,
p = momentum
m = mass of object = 2 kg
Let the upward velocity be positive and the downward velocity be negative
When the object is dropped, the velocity is downward
v = -5m/s
Initial momentum = [tex]2kg\times (-5m/s)=-10kg.m/s[/tex]
When the object is bounced back, the velocity is upward
v = +5m/s
Final momentum = [tex]2kg\times (+5m/s)=10kg.m/s[/tex]
Change in momentum = Final - Inital
Change in momentum = [10 - (-10)] = +20 kg.m/s
Hence, the change in momentum is +20 kg.m/s
Find the emitted power per square meter and wavelength of peak intensity for a 3000 K object that emits thermal radiation.
Answers
Answer:
power per square meter = 4.593 × 10^(6) W/m²
Wavelength of peak intensity = 9.67 × 10^(-7) m
Explanation:
From Stefan-Boltzmann law, total emitted power per square meter is given as;
P/A = eσT⁴
where;
P is power
A is surface area
σ = Stefan-Boltzmann constant = 5.67 × 10^(-8) W/m².k⁴
T = temperature of the body = 3000 K
e = emissivity of the substance (for ideal radiation, it has a value = 1)
Thus, Plugging in the relevant values we have;
P/A = 1 × 5.67 × 10^(-8) × (3000)^(4)
P/A = 4.593 × 10^(6) W/m²
Let's find the wavelength of peak intensity.
From wiens displacement law, we know that;
λ_m × T = b
where;
λ_m = maximum wavelength
T = Temperature
b is Wien's displacement constant = 2.9 × 10^(−3) m/K
thus;
λ_m = b/T = (2.9 × 10^(−3))/3000 = 9.67 × 10^(-7) m
A bicyclist rides 2.93 km due east, while the resistive force from the air has a magnitude of 8.65 N and points due west. The rider then turns around and rides 2.93 km due west, back to her starting point. The resistive force from the air on the return trip has a magnitude of 8.65 N and points due east. Find the work done by the resistive force during the round trip. Number Type your answer here Units Choose your answer here
Answers
Answer:
-50.6 kJ
Explanation:
The work done (W) on an object is given by:
W = (Fcosθ) * S
where F is the force, S is the displacement and θ is the angle between the force and displacement.
i) During the first trip riding east, S₁ = 2.93 km = 2930 m, F₁ = 8.65 N.
The displacement is due east and the force is due west, hence θ₁ = 180°. Therefore:
W₁ = (F₁ * cosθ₁)S₁ = (8,65 * cos(180))2930 = -25.3 kJ
ii) i) During the second trip riding west, S₂ = 2.93 km = 2930 m, F₂ = 8.65 N.
The displacement is due west and the force is due east, hence θ₂ = 180°. Therefore:
W₂ = (F₂ * cosθ₂)S₂ = (8,65 * cos(180))2930 = -25.3 kJ
work done by the resistive force during the round trip is:
W = W₁ + W₂ = -25.3 kJ + (-25.3 kJ) = -50.6 kJ
The valid digits in a measurement are called _____ digits.
Answers
Answer:
Significant
Explanation:
As the word suggests, significant figures or digits are numbers that are valid in measurement.
Answer:
SIGNIFICANT DIGITS
Explanation:
MARK ME BRAINLIEST PLZZZ
The auroras occur in the
C.
a. troposphere
b. stratosphere
mesophere
d. ionosphere
Answers
Answer:
Ionosphere
Explanation:
The thermosphere reaches 600 kilometres just above mesosphere and begins immediately above the mesosphere. This layer is where the aurora and satellites appear.
The ionosphere is the comprehensive career of the mesosphere because most of the thermosphere, located 80–400 kilometres just above ground atmosphere.
Auroras — magnificent flowing streaks of light seen in the night sky – appear in this location.
In what way is Height related to Potential Energy?
Answers
Explanation:
Lets say you have a ball in your hand, you raise your hand to just above your head. Now, when you did that you created potential energy that is ready to be released. you drop the ball and the ball bounces a few times off the ground. Now lets say you got a ladder and doubled the ball's height doubling the energy now stored in the ball, when you drop it the ball should bounce much higher after hitting the ground as a result of more energy being released.
Hope this helped.
Three voltmeters V, V₁ and V₂ are connected as in
Figure 37.9. a If V reads 18V and V, reads 12V, what does V₂ read?
b If the ammeter A reads 0.5A, how much electrical energy is changed to heat and light in lamp L₁ in one minute? c Copy Figure 37.9 and mark with a + the positive terminals of the ammeter and voltmeters for correct
connection.
Answers
Answer:
a. V₂ = 6 V
b. 360 joules
c. The positive terminals of both the voltmeter and ammeter are connected to the positive terminal of the power source
Please see the attached drawing created with MS Visio
Explanation:
a. The voltmeter readings are;
V₁ = 12 V, V = 18 V
Given that the voltage reading, 'V', is the voltage reading across two loads with voltages, V₁ and V₂ connected in series, we have;
V = V₁ + V₂
V₂ = V - V₁
V₂ = 18 V - 12 V = 6 V
b. The reading of the ammeter, A, I = 0.5 A
The heat energy, Q = I·V·t
Where;
t = The time = 1 minute (60 seconds)
Therefore, for the lamp L₁, where V = 12 V, we have;
Q₁ = 0.5 A × 12 V × 60 s = 360 Joules
The amount of electrical energy changed into heat and light in lamp L₁, Q₁ = 360 joules
c. The positive terminals of the voltmeter and ammeter are connected to the positive terminal of the power source
Please see attached drawing created with MS Visio
in a series circuit, how does the voltage supplied by the battery compare to the voltages on each load?
Answers
Answer:
In a series circuit, how does the voltage supplied by the battery compare to the voltage on each load? The voltage of the battery is equal to the voltage of each load added together. ... The voltage across the two resistors must both have the same voltage of the battery.
Explanation:
mark me as BRAINLIEST
follow me
carry on learning
Answer:
The voltage of the battery is equal to the voltage of each load added together. The voltage across the two resistors must both have the same voltage of the battery.
>3
if a train starts from rest and attains a velocity of 100m/s in 25 seconds. calculate the acceleration produced by the train.
Answers
Explanation:
0-100/25
-100/25
-4
In this experiment, the ______ was intentionally manipulated. This was the independent variable.
A. fan speed
B. mass
C. acceleration
Answers
Answer:
Fan speed
Explanation:
because is the dependent variable
what is potential difference??. Please give a detailed explanation.
Answers
Explanation:
The difference of electrical potential between two points is called the potential difference.
It is also defined as the work done in the transfer of a unit quantity of electricity from one point to the other.
The SI unit of electric potential is volt. It is denoted by V.