Answer: 25
Explanation ;)
Which statement about the photoelectric effect is true?
A When light acts as a wave, electrons are removed from a metal,
B. It occurs when an electric current causes light to be produced,
C. An electric current is produced when light shines on a surface,
D. It occurs any time an electric current is produced.
Answer: A
Explanation:
The photoelectric effect was first proposed by Einstein. He claimed that when a light wave comes in contact with an electron, it has the ability to strip that electron from its atom. It depends on how much energy the light wave is carrying, and what type of atom the light is hitting. We use the photoelectric effect in garage motion sensors.
What is the wave speed of a wave if the wavelength is 100 m and the period is 2 seconds?
Explanation:
speed =frequency *wavelength
frequency=1/2
=0.5Hz
speed=0.5*100
50m/s
A cork on the surface of a pond bobs up and down two times per second on ripples having a wavelength of 8.80 cm. If the cork is 10.5 m from shore, how long does it take a ripple passing the cork to reach the shore?
Answer:
12m / 7.3*10^-2m/cy = 164.38 cycles.
164.38cy / 2cy/s = 82.2s.
Explanation:
A student pedaling a bicycle applies a net force of 250 N. The mass of the rider and the bicycle is 48 Kg. Assuming no friction is present, what is the acceleration of the bicycle and rider? (1 N= 1.0 kg-m/sec?)
What is significant about the temperature 0 K
A. Matter no longer exists
B. Ice melts
C. Water freezes
D. Particles no longer move
Answer: I's either A. Matter no longer exists or D. Particles no longer move
Explanation:
Sorry if I get it wrong
Hope his helps :)
Answer:
d
Explanation:
5.) Scott pushes a piano along a slope and has an initial velocity of 10.0 m/s [up]. Its acceleration is 2.0 m/s2 [down].
a.) After its release, what is the piano’s velocity at 2.0 s, 5.0 s and 8.0s? b.) What is the piano’s displacement at 2.0 s, 5.0 s and 8.0s?
Answer:
a) 6m/s, 0m/s, -6m/s
b) 16m, 25m, 16m
Explanation:
For the first part of the problem, use the Kinematic Equation for Final Velocity:
V = Vi + atYou are looking for the final velocities of the times: 2s, 5s, and 8s (plug those in for t). We also know that the acceleration is going down so it is negative (-2 is plugged in for a). 10 is the initial velocity and it is positive.
For the second part of the problem, use the Kinematic Equation for Displacement:
ΔX = Vi(t) + 1/2a(t²)You are looking for the displacement of the piano at times: 2s, 5s, and 8s (plug in and square at t). Again, the acceleration is negative because it is in the direction of down, so plug -2 in for a. The initial velocity is positive 10. Plugging those numbers in for each variable should get the correct answer.
Hopefully this helped, I went on here in search of an answer and found it out myself and since no one has answered it yet, I'll help someone else out.
A 12.0-kilogram mass weighs 84.0 newtons on a newly discovered planet. What is the magnitude of the acceleration due to gravity on this planet?
A. 1.20 m/s²
B. 7.0 m/s²
C) 9.8 m/s²
D. 84 m/s²
Acceleration be a
Apply Newton's second law
[tex]\\ \rm\Rrightarrow F=ma[/tex]
[tex]\\ \rm\Rrightarrow a=\dfrac{F}{m}[/tex]
[tex]\\ \rm\Rrightarrow a=\dfrac{84}{12}[/tex]
[tex]\\ \rm\Rrightarrow a=7m/s^2[/tex]
[tex] \huge\bf\underline{solution}[/tex]
Mass of given body (m) = 12Kg
Force (F) = 84.0N
We have been asked to find the magnitude of of the acceleration .
[tex] \huge\bf\purple{force = mass \times acceleration}[/tex]
Put all the given value we get
[tex] \sf \dashrightarrow84 = 12 \times acceleration \\ \\ \sf \dashrightarrow \frac{84}{12} = acceleration \\ \\ \sf \dashrightarrow7 {ms}^{ - 2} = acceleration[/tex]
So, the acceleration due to gravity on that planet is 7m/s² .
So Your answer is B) 7.0m/s²
Density = Mass/Volume
If a ball has a mass of 25g and a Volume of 50ml, what is the Density of the ball?
Answer: 0.5
mass=50
volume=25
25/50=0.5
Identify the number of electrons each of the following atoms needs to gain or lose to have a stable outer electron configuration.
sodium (Na):
strontium (Sr):
sulfur (S):
astatine (As):
Parents who make few demands on their children and use little punishment are what?
Answer:
Permissive - allowing or characterized by great or excessive freedom of behavior.
Explanation:
Hope this helps! Please let me know if you need more help, or if you think my answer is incorrect. Brainliest would be MUCH appreciated. Have a great day!
A transformer bank is rated at 300kva and consists of three 100kva transformers has a three phase 480v delta primary and a 120v/240v 3phase, 4 wire delta connected secondary. What is the calculated rating of the transformers primary and secondary currents?
The rating of the transformers primary and secondary currents will be 360.8A and 180.4A.
How to calculate the current?From the information given, the rating of the transformer bank is given as 300kVA. The full load primary current will be:
✓3 × V × I = 300 × 10³
✓3 × 480 × I = 300 × 10³
I = 360.8A
Also, the secondary load current will be calculated thus:
Transformation ratio = 240/480 = 0.5
Load current = 360.8 × 0.5
= 180.4 A
In conclusion, primary and secondary currents will be 360.8A and 180.4A.
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PLEASE HELP I NEED THIS FAST
Describe how electric potential energy, kinetic energy, and work change when two charges of opposite sign are placed near each other.
Answer:
If the charges have the same sign, so that qsqt>0, then the potential energy decreases as the charges separate; if the charges have opposite sign, the potential energy increases from negative infinity.
Explanation:
I hope this answered your question!
Which forces can be either attractive or repulsive.
Answer:
Magnetic forces.
When the magnets are put together, the north pole is attracted to the south pole, which the south pole goes toward the opposing pole on the opposite magnet. Complicated, yes, but how magnets work.
I hope this helps!
1. What is the weight (force due to gravity) of an object that has a mass of 15 kg?
Answer: 1470 N
Explanation: mass = 15
weight is the product of mass and force due to gravity
AS WE KNOW THAT
W = mG
W = 15 X 9.8
W = 1470 N
Calculate the answer to the correct number of significant digits.
-0.166
×0.033
The maximum induced emf in a generator rotating at 28 rad/s is 35 v. How fast must the rotor of the generator rotate if it is to generate a maximum induced emf of 65 V?
Answer:
148
Explanation:
you have to add 28+35+65
In a stable ecosystem, the number of predators _____________ if the number of prey increases. Question 12 options: Decreases Stays the same Increases Dies.
In a stable ecosystem, the number of predators increases if the number of prey increases.
What is the relation between predators and prey?Predators are the species that are dependent upon prey for their foods. predators actually hunt the prey for their food.
predators are the species that depend upon other living species like deer fish goats etc for example lions depend upon deer, zebras, etc.
while the preys are the species who depend upon the plants for their food so if the number of preys will be higher then the number of the predators will also be higher.
Thus In a stable ecosystem, the number of predators increases if the number of prey increases.
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What is parallel connection
If it takes 20 seconds to push the table across the room.What is the power ?
Answer: Its applied force and friction, The friction is the drag and the applied force is you pushing
SOMEONE PLEASE HELPPP!
Answer:
The first and third one
Explanation:
The roughness of the surfaces is very important when determining friction as well as the force pressed on a surfaces as it helps increase friction.
HOPE IT HELPED
In urgent need of help, science is my worse subject!
The first reason is that in the past humans didn't necessarily see the connections between the oceans and thus labelled them that way separating them into 5 oceans and the names stuck to this day.
Secondly, while all the oceans of the world constitute one large Ocean, people need some way to identify each part of it since it is easier to think when we have different categories instead of one large category.
Hope that helped!
A 20N net force acts upon an object with a mass of 4. 0kg. What is the object's acceleration?
Answer:
5ms^-2
Explanation:
F = 20N, m = 4.0kg, a = ?
Using the formula for Force
F = ma
Then making acceleration the subject of the formula
a = F/m
a = 20N/4.0kg
a = 5ms^-2
A tennis ball with a speed of 22.2 m/s is moving perpendicular to a wall. After striking the wall, the ball rebounds in the opposite direction with a speed of 14.9184 m/s. If the ball is in contact with the wall for 0.00965 s, what is the average acceleration of the ball while it is in contact with the wall? Take "toward the wall" to be the positive direction. Answer in units of m/s 2
Answer:
[tex]a=-3846.46\ m/s^2[/tex]
Explanation:
Given that,
Initial velocity of the ball, u = 22.2 m/s
Final velocity of the ball, v = -14.9184 m/s (minus sign shows opposite direction of motion)
Time for contact, t = 0.00965 s
We need to find the average acceleration of the ball when it is in contact with the ball. The acceleration of an object is equal change in velocity per unit time. So,
[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{-14.9184 -22.2 }{0.00965 }\\\\a=-3846.46\ m/s^2[/tex]
So, the acceleration of the ball is [tex]3846.46\ m/s^2[/tex] towards the opposite direction of motion.
HELP HELP
Preview the map listed below. List 5 questions about this map that will help predict the text. Use your 5 W’s and h questioning techniques. Predict what the text will be about.
A map of Africa with two keys. The first key uses symbols to represent goods and resources that come from Africa such as cocoa, coffee, rice, rubber. The second key uses color to represent activities in Africa such as commercial plantation agriculture, irrigated agriculture, livestock raising, Nomadic herding.
The text that can be inferred from the map is about the crops that are gotten from Africa and how agriculture can be developed in the area.
What is agriculture?It should be noted that agriculture simply means the planting of crops and rearing of animals for human use.
In this case, the text that can be inferred from the map is about the crops that are gotten from Africa and how agriculture can be developed in the area.
The use of irrigation, and nomadic herding can be sent in Africa. Therefore, this can be the central idea in the text.
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Answer:
Who was involved in the listed keys on the map provided?
What happened to symbols representing goods and resources that come from Africa?
When did commercial plantation agriculture, irrigated agriculture, livestock raising, and Nomadic herding occur in Africa?
Where did cocoa, coffee, rice, and rubber cone originate in Africa?
Why did Africa transpire as commercial plantation agriculture, irrigated agriculture, livestock raising, and Nomadic herding?
How did it change over time?
Explanation:
A force is applied to a block, causing it to accelerate along a horizontal, frictionless surface. The kinetic energy gained by the block is equal to which of the following
Answer:
The work done to the block
See
Workdone is Force×Displacement .
Also work done is total mechanical energy of body
As potential energy is 0Mechanical energy=Kinetic energy
So option C is correct
Why are electromagnets, rather than permanent magnets, used in MRLs?
Answer:
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Explanation:
1. How many bones are in the collection?
Answer:
Explanation:
The NISP of the bones found in the park is 22. 2. The bones that belong to the axial skeleton is the 3 skulls, and the bones that belong to the appendicular skeleton are the 6 femora, 4 hip bones, 2 humerus, 2tibiaes, and 5 scapula bones.
Hope it helps.... :)
A car has a mass of 1000 kg. What is the acceleration produced by a force of 2000 N?
Newton's 2nd Law of Motion states:
F = ma
Which statement describes how the coil of wire is similar to a bar magnet?
(1 point)
o They both have north and south magnetic poles.
o They both require a battery or other power source.
O They both have no influence on the current in the wire.
OThey both keep the magnetic field strength the same.
Answer:
They both have North and South magnetic poles
Explanation:
No matter how a magnet is made or what material it will have both resistance and attraction
How are mass and acceleration related?
Answer:
The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.
Explanation: