Answer:
Power
step by step explanation:
Which of these is untrue about ray diagrams?
A. The arrowheads show the direction of the light
B. Lines must always be straight
C. More arrowheads on lines mean a brighter light
Answer:
The untrue option is C: "More arrowheads on lines mean a brighter light"
Explanation:
Ray diagrams are used to show how the light behaves with things like mirrors or lenses. Where we only study how the direction of the light changes when it interacts with these objects.
The "light" is represented with arrows, where again, the only thing we care is the direction of the light, so the first statement is true, the arrowheads show the direction of the light, and only that.
The intensity of the light, in this context, has no effect on how light behaves, so there is not a necessity of representing the intensity of the light, thus, more arrowheads on lines do not mean a brighter light. It may only be used to represent changes in direction of the light.
Finally, we know that light travels in straight pats (the pats can be curved in some cases, like with large gravitational fields, but this is not the case of a ray diagram) so the lines that represent the light should always be straight, thus option B is also true.
The untrue option is C: "More arrowheads on lines mean a brighter light"
if a train starts from rest and attains a velocity of 100m/s in 25 seconds. calculate the acceleration produced by the train.
Find the emitted power per square meter and wavelength of peak intensity for a 3000 K object that emits thermal radiation.
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
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?
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.
Why do we see different phases of the lunar cycle?
A) As the moon rotates around its axis, different sides of it become visible.
B) as the earth rotates its axis, people can see different sides of the moon.
C) as earth revolves around the sun, the moon is cast into different shadows by earth.
D) as the moon revolves around earth, the different amounts of the sunlit side faces earth.
Answer: The answer is: D) as the moon revolves around earth, the different amounts of the sunlit side faces earth.
Explanation: I have my ways ;>
Have a great day!
-Sunny
In what way is Height related to Potential Energy?
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.
The unit of area is a derived unit. Why?
Explanation:
area=length(m) ×breadth(m) . The unit of area is expressed in terms of fundamental units m^2.thus it is derived unit
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
Answer:
The 80 mph car
Because the formula says 1/2 mass but for the velocity it is squared
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?
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
in a series circuit, how does the voltage supplied by the battery compare to the voltages on each load?
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:
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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
Which of the following is not a true statement
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?
An aluminium cube of side 5cm and R.D 2.7 is suspended by a thread in alcohol of relative density 0.8o. Find the tension in thread.
Answer:
The tension in the thread is approximately 3.2103225 Newtons
Explanation:
The given parameters are;
The side length of the aluminum cube, s = 5 cm
The R.D. of aluminum = 2.7
The relative density of alcohol into which the aluminum cube is placed = 0.8
The volume of the aluminum cube, V = s³ = (5 cm)³ = 125 cm³
The mass of the aluminum cube, V = The volume of the cube
The mass of the aluminum cube, m = V × R.D. × Density of water
m₁ = 0.000125 × 2.7 × 970 = 0.327375 kg
The mass of the alcohol displaced, m₂ = 0.000125 × 0.8 × 970 = 0.097
The tension in the string, T = The apparent weight of the aluminum cube, Wₐ
∴ The tension in the thread, T = Wₐ = (m₁ - m₂) × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
∴ T ≈ (0.327375 - 0.000125) × 9.81 = 3.2103225
The tension in the thread, T ≈ 3.2103225 N.
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
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
How many players are allowed to play for one team during a game of
5 points
Netball?
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
what is potential difference??. Please give a detailed explanation.
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.
A ball is thrown vertically up. If the ball reached at maximum height in 3s. Assume air resistance is negligible. What is the initial velocity of the ball. (Answer using a coordinate system where upwards is positive)
Answer:
Explanation:Gravitational force always acts on the ball in the downward direction, thus an acceleration due to gravity always point in the downward direction with a constant magnitude 10.6m/s
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) .
Answer:
there it is fella atleast i tried
A current of 17 A flows through a resistor of 10 2. What is the voltage
across the resistor
calculate the volume of a ball having radius of 8 cm
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
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
Answer:
Jupiter and neptune
Explanation:
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.
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
The valid digits in a measurement are called _____ digits.
Answer:
Significant
Explanation:
As the word suggests, significant figures or digits are numbers that are valid in measurement.
Answer:
SIGNIFICANT DIGITS
Explanation:
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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
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
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
A chemical reaction is the change that takes place when ____ or more substances interact to form new substances.
Answer:
two or more substances
Explanation:
A chemical reaction can't take place if there is only one substance
Answer:
A chemical reaction is the change that takes place when two
or more substances interact to form new substances.
Explanation:
Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.
In this experiment, the ______ was intentionally manipulated. This was the independent variable.
A. fan speed
B. mass
C. acceleration
Answer:
Fan speed
Explanation:
because is the dependent variable
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?
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
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.
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
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
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.