Answer:
Consequently the statement is FALSE
Explanation:
The process of emission of electrons or photoelectric effect, was explained by Einstein, assuming that light behaves as formed by how many so-called photons and each one of them collides with an electron, therefore to start an electron the incident photon energy must be greater than the work function of the material.
E =K + Ф
By mentioning the intensity we increase the number of photons but we do not increase their energy.
Consequently the statement is FALSE
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"
What is kinetic and potential energy?
Answer:
the energy produced in a body due to its motion is kinetic energy.
energy produced in a body due to its position is potential energy.
Explanation:
kinetic energy is the energy possessed by a body in motion
Potential energy is the energy possessed by a body by virtue of its position with respect to a reference level
A partially inflated balloon is faded over the open end of a glass beaker that contains water the beaker is placed in an ice bath which cause the water and causes the balloon to the flea what are the correct designs for the heat and work changes to the beaker and balloon system
Answer:
a
Explanation:
ASAPP PLS HELP MEE
The density of aluminum is 2.7 g/cm^3. Which of the following statement is true?
A) 1 g of aluminium has a volume of 1 cm^3
B) 2.7 g of aluminium has a volume of 1 cm^3
C) 1 g of aluminium has a volume of 2.7 cm^3
D) 2 g of aluminium has a volume of 7 cm^3
Answer:
B) 2.7 g of aluminium has a volume of 1 cm^3
Explanation:
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
If the density of aluminum is 2.7 g/cm³, it simply means that 2.7 g of aluminium has a volume of 1 cm³
Check:
Given the following data;
Mass = 2.7 grams
Volume = 1 cm³
Substituting into the formula, we have;
[tex]Density = \frac{2.7}{1}[/tex]
Density = 2.7 g/cm³
when a car drives in a circle there must be ?
no net force axting on it
Answer:
I think none of above
Explanation:
hioe it's right answer
The dependent variable measured was the ______
a. fan speed
b. mass
c. acceleration
Answer:
a
Explanation:
Fan speed is the answer
Behaviors in deer such as herding and male deer using antlers to compete for females increase the chances of successful reproduction.
True or False
Answer:
True
Explanation:
The reproductive success of any species is the capability to produce their offspring per breeding lifetime or event.
Most of the species have to attract their partners by their physical capability and build up so that the mother can choose her partner in order to breed the best kind of off spring.
In the context, in case of deer, the size of the their antlers as well as behavior in herding is considered as the best chances for a successful reproduction to compete among the males and find their breeding mate.
Thus the answer is TRUE.
Give atleast (5) etypes of cleaning tools , equipment,supplies, and materials that you can find either in your home or school. Identify each use
Answer and Explanation:
Cleaning tools, equipment, supplies, and materials that can be easily found in a school in one each are: scrub brush, sponges, buckets and brooms.
These equipments are essential to promote a clean, organized and safe environment and for this reason, they can be easily found both at school and in a home, since the cleanliness of these two places is essential for the well-being, proactivity and health of the people who attend them.
The three scientists credited with using all available data and correctly determing the sturcture of dna from many years of previous work are
Answer:
James Watson, Francis Crick, and Maurice Wilkins
Explanation:
The three scientists that used the available data ( x-ray images of DNA provided by Rosalind Franklin) to correctly determine the structure of DNA are : James Watson, Francis Crick, and Maurice Wilkins.
These scientists discovered the structure of DNA in 1953 and they received, and they receive a Nobel Prize in Physiology or Medicine for their discovery
help....................
Please help!!!!! I will give brainliest. Describe four examples of acceleration you see during your day. Choose an object that is slowing down, one that is speeding up, one that is moving at a constant speed but changing direction, and one that is moving at a constant velocity with zero acceleration.
When the brake is applied to the car and comes to rest after some time is an example of an object that is slowing down.
What is acceleration?The rate of change of velocity with respect to time is known as acceleration. According to Newton's second law, the eventual effect of all forces applied to a body is its acceleration.
1. When the brake is applied to the body and comes to rest after some time is an example of an object that is slowing down.
2. When a person accelerates the car and the velocity is increasing is an example of speeding up.
3. An object moves in a circular motion moving at a constant speed but changing direction,
4. Acceleration is the rate of change of velocity. If the change in the velocity is constant the acceleration is zero is an example of moving at a constant velocity with zero acceleration.
To learn more about acceleration, refer to the link;
https://brainly.com/question/2437624
#SPJ1
A puck is travelling at a speed of 28 m/s. If it has a mass of 200 g, what is its momentum?
Answer:
Explanation:
Momentum is equal to mass times velocity:
p = mv; therefore,
p = .200(28) and
p = 5.6 [tex]\frac{kg*m}{s}[/tex]
DO U KNOW CARRYMINATI
A constellation’s changing position in the sky, at the same time of the evening, over a period of several weeks is evidence that:
a- Earth is round b- Earth’s axis is tilted. c- Earth rotates on its axis.
d- Earth revolves around the sun.
Answer:
d- Earth revolves around the sun.
Explanation:
Earth rotation can be defined as the amount of time taken by planet earth to complete its spinning movement on its axis.
This ultimately implies that, the rotation of earth refers to the time taken by earth to rotate once on its axis. One spinning movement of the earth on its axis takes approximately 24 hours to complete with respect to the sun.
On the other hand, earth revolution can be defined as a complete trip along a path around the sun. This path is known as an orbit and it typically takes the Earth 365¼ days to complete it's journey around the Sun.
When a constellation (stars) changes its position in the sky, at the same time of the evening and over a period of several weeks; it ultimately implies or is an evidence that Earth revolves around the sun.
If a serve hits the net, what happens?
• Re-do
• Dead Ball
• Other teams point
• Play the ball
Answer:
Depends: Is it tennis or volleyball?
Explanation:
If it's volleyball, it's C, the other teams point.
If it's tennis, it's A, you get a re-do.
Hai tiếp điểm hình trụ bằng đồng có đầu hình cầu bán kính R = 70mm, lực ép tiếp điểm F = 100N, Mô đun đàn hồi của đồng là 11.8 * 106(N/cm2). Cho biết: a = 0.86 * (F*R/E)1/3, điện trở suất của đồng là 1.62 * 10-8 (Ω/m), với tiếp điểm đồng thì hệ số K1 = 3,16.10-4 (ΩN1/2). Biết các giá trị ứng suất của đồng là: σdh = 38300 N/cm2; σdẻo = 45000 N/cm2; σd.Nát = 51000 N/cm2. Tính điện trở tiếp xúc trong trường hợp thỏa mãn điều kiện tản dòng lí tưởng và trong trường hợp thực nghiệm.
Answer:
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A cell has an emf of 1.5 V and an internal resistance of 0.65 Q.
The cell is connected to a resistor R.
[0[8].[4] State what is meant by an emf of 1.5 V.
[2 marks]
I
[0] 8]-[2] The current in the circuit is 0.31 A.
Show that the total power output of the cell is approximately 0.47 W.
[1 mark]
[o[s).[3] Calcutate the energy dissipated per second in resistor R.
[2 marks]
energy dissipated per second = Ist
[o[si.[4] The cell stores 14 kJ of energy when it is fully charged. The cell's emf and internal resistance are constant as the cell f discharged.
Calculate the maximum time during which the fully-charged cell can deliver energy to
resistor R.
[2 marks)
maximum time = 5
Answer:
14000 J / 0.40 J/s = 35 000 s or about 9.75 hrs
A sled with mass 11.00 kg moves in a straight line on a frictionless horizontal surface. At one point in its path, its speed is 4.00 m/s; after it has traveled a distance 3.00 m beyond this point, its speed is 7.00 m/s. Use the work-energy theorem to find the force acting on the sled, assuming that this force is constant and that it acts in the direction of the sled's motion.
Answer:
The magnitude of the force acting on the sled is 60.5 newtons.
Explanation:
The Work-Energy Theorem states that the work done by the external force applied on the sled ([tex]W[/tex]), in joules, is equal to the change of its translational kinetic energy ([tex]\Delta K[/tex]), in joules:
[tex]W = \Delta K[/tex] (1)
By definitions of work and translational kinetic energy we expand the equation above:
[tex]F\cdot s = \frac{1}{2}\cdot m\cdot (v_{2}^{2}-v_{1}^{2})[/tex] (1b)
Where:
[tex]F[/tex] - External force applied on the sled, in newtons.
[tex]s[/tex] - Travelled distance, in meters.
[tex]v_{1}, v_{2}[/tex] - Initial and final velocities, in meters per second.
If we know that [tex]m = 11\,kg[/tex], [tex]v_{1} = 4\,\frac{m}{s}[/tex], [tex]v_{2} = 7\,\frac{m}{s}[/tex] and [tex]s = 3\,m[/tex], then the external force applied on the sled is:
[tex]F = \frac{m\cdot (v_{2}^{2}-v_{1}^{2})}{2\cdot s}[/tex]
[tex]F = \frac{(11\,kg)\cdot \left[\left(7\,\frac{m}{s} \right)^{2}-\left(4\,\frac{m}{s} \right)^{2}\right]}{2\cdot (3\,m)}[/tex]
[tex]F = 60.5\,N[/tex]
The magnitude of the force acting on the sled is 60.5 newtons.
Susan claims that she can throw a dart at a dartboard from a distance of 3.0m and hit the 5.0cm wide bull's-eye if she throws horizontally with a speed of 20 m/s. She starts to throw at the same height as the top of the bull's-eye. Will Susan hit the bull's-eye?
What is being asked? How to calculate?
what is time write its SI unit
Change the following as indicated in the brackets.
8m (km,cm)
metres to kilometres = 1/1000
8 m ⇒ 0.008 km
metres to centimetres = × 100
8 m ⇒ 800 cm
Answer:
1000m=1km
so, 8m=8/1000 = 0.008km
1m=100cm
so, 8m=8×100=800
QUESTION 30 A tennis ball moves back and forth 10 times in 5 sec. The frequency of its motion is
Answer:
so in 1 sec 2 times
so frequency = 2
Explanation:
If the amplitude of a sound wave is increased by a factor of four,how does the energy carry by the sound wave in each time interval change?
Answer:
The energy will be increased by a factor 16
Explanation:
Mathematically, we have it that the energy carried by the sound wave is directly proportional to the square of the amplitude
So we have it that;
E = k * A^2
where E is the wave energy
K is the constant value
A is the amplitude value
So;
If E1 = k * (A1)^2
E2 = k * (A2)^2
But A2 = 4A1
E2 = k * (4A1)^2
E2 = k * 16(A1)^2
Divide E2 by E1
E2/E1 = k/k * 16(A1)^2/(A1)^2
E2/E1 = 16
E2 = 16 * E1
so simply, the energy will be increased by a factor of 16
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
Brass is made by melting a mixture which contain 67% by mass of copper and 33% by mass of zinc if no change in volume.Calculate the density of brass
Answer:
The density of brass is approximately 8,261.73 kg/m³
Explanation:
The percentage composition by mass of brass is given as follows;
The percentage by mass of copper = 67%
The percentage by mass of zinc = 33%
The density of copper, ρ₁ = 8.96 g/cm³
The density of zinc, ρ₂ = 7.133 g/cm³
Therefore, where we have, m = 100 g of brass, we have;
The mass of copper, m₁ = 67 g
The volume of copper, V₁ = m₁/ρ₁
∴ V₁ = 67 g/(8.96 g/cm³) ≈ 7.47767857 cm³
The volume of zinc, V₂ = m₂/ρ₂
∴ V₂ = 33 g/(7.133 g/cm³) ≈ 4.62638411 cm³
The volume of the brass, V = V₁ + V₂
V = 7.47767857 cm³ + 4.62638411 cm³ ≈ 12.104 cm³
The density of brass, ρ = m/V
∴ ρ = 100 g/(12.104 cm³) ≈ 8.26 g/cm³
The density of brass, ρ ≈ 8.26 g/cm³ = 8,261.73 kg/m³
which of the following items has the most inertia while at rest
Answer:
wats the following items
if a train starts from rest and attains a velocity of 100m/s in 25 seconds. calculate the acceleration produced by the train.
Why is a person not a good blackbody radiator?
O A. A person emits only visible light.
OB. A person emits only infrared radiation.
O C. A person absorbs most of the light that hits him or her.
O D. A person reflects little of the light that hits him or her.
Answer:
O C. A person absorbs most of the light that hits him or her.
Explanation:
Answer:
Option D hope it's helpful mark me as brainlistTwo parallel circular rings of radius R have their centres in the X axis separated by a distance L. If each ring carries a uniformly distributed charge Q,find the electric field at points along the X axis
Answer:
E" = Q/4πε₀√[(x² + R²)]³(x - (L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
Explanation:
The electric field due to a charged ring of radius R at a distance x from the center of the ring when the axis of the ring is located on the x - axis is
E = Qx/4πε₀[√(x² + R²)]³
Since the rings are separated by a distance L, the electric field at point x due to the second ring is E' = -Q(L - x)/4πε₀[√((L - x)² + R²)]³. It is negative since it points in the negative x - direction.
So, the resultant electric field at x is E" = E + E' = Qx/4πε₀[√(x² + R²)]³ + {-Q(L - x)/4πε₀[√((L - x)² + R²)]³}
E" = Qx/4πε₀√[(x² + R²)]³ - Q(L - x)/4πε₀√[((L - x)² + R²)]³
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[((L - x)² + R²)]³})
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[(L² - 2Lx + x² + R²)]³})
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[(L - 2x)L + (x² + R²)]³})
E" = Q/4πε₀√[(x² + R²)]³(x - (L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
So, the electric field at points along the x axis is
E" = Q/4πε₀√[(x² + R²)]³(x - {(L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
A box at rest is in a state of equilibrium half way up on a ramp. The ramp has an incline of 42° . What is the force of static friction acting on the box if box has a gravitational force of 112.1 N ?
70 N
80 N
75 N
85 N
Answer:
the correct answer is 75 N
Explanation:
This is a translational balancing exercise, let's set a reference system with the x-axis in the direction of the plane and the y-axis perpendicular to the plane.
In this reference system the force to decompose is the weight
sin 42 = Wₓ / W
cos 42 = W_y / W
Wₓ = W sin 42
W_y = W cos 42
Wₓ = 112.1 sin 42 = 75.0 N
W_y = 112.1 cos 42 = 83.3 N
The expression for equilibrium on the x-axis is
Wₓ - fr = 0
fr = Wₓ
fr = 75.0 N
the correct answer is 75 N
