Answer:
the time taken for the radioactivity of a specific isotope to fall to half its original value.
the time required for any specific property (e.g. the concentration of a substance in the body) to decrease by half.
Explanation:
I don't know if that's what your looking for
Two neutral objects - object A and object B - are rubbed together. During the process,
electrons are transferred from object A to object B. This would cause object A to acquire
a charge and object B to acquire a charge.
Answer:
I think it is + and + I could be wrong but I hope it helps
3.Three resistors of 25.0Ω, 30.0Ω, and 40.0Ω are in a series circuit with a 6.0-volt battery. What is the current in the circuit?
please answer by steps
Answer:
Current = 0.063 Amperes
Explanation:
Let the three resistors be R1, R2, and R3 respectively.
Given the following data;
R1 = 25.0Ω,
R2 = 30.0Ω
R3 = 40.0Ω
Voltage = 6 Volts
First of all, we would determine the equivalent or total resistance;
Total resistance (in series) = R1 + R2 + R3
Total resistance = 25.0Ω + 30.0Ω + 40.0Ω
Total resistance = 95 Ω
Next, we find the current flowing through the circuit;
Voltage = current * resistance
Substituting into the formula, we have;
6 = current * 95
Current = 6/95
Current = 0.063 Amperes
The _____ of a mechanical wave is a direct measure of its energy.
speed
frequency
amplitude
hertz
I'm stuck between B and C
In the problem, I know the potential energy increases because the height increases.
A block is at the bottom of a frictionless ramp and is given a kick so that it has some initial velocity and starts to slide up the ramp. There
is no air resistance. Which of the following is true of the energy of the block as it slides?
(A) Its potential energy will increase; its kinetic energy will decrease.
(C) Both its potential and kinetic energies will increase.
(B) Its potential energy will decrease; its kinetic energy will increase.
(D) Both its potential and kinetic energies will decrease.
Answer:
Explanation:
The answer is A. First of all, due to the First Law of Thermodynamics, energy cannot be created or destroyed, it only changes form. That being said, it is impossible for the PE and the KE to both increase or decrease at the same time. The second one starts decreasing, the other starts increasing at the exact same rate. PE exists or is at its highest when an object has the potential to fall to a point lower than it is, and it is at this point where Kinetic energy is the lowest. If this block is kicked UP a ramp, which is odd but there you have it, the potential energy increases as it gets higher off the ground. Because of gravity, and assuming that once the block is kicked, the foot that kicked it is no longer important to it (meaning it's not being pushed up, it's just kicked once and that's it) and it will slow down very quickly. KE exists where there is a great amount of velocity.
The answer is A.
Boxers wear gloves that are padded to lessen the force of a punch. Calculate the force exerted by a boxing glove on an opponent's face, if the glove and face compress 8.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. Give your answer in Newtons, do not include the unit in your answer.
Answer:
F = 4117.64
Explanation:
First, we will calculate the acceleration of the hand, by using the third equation of motion:
[tex]2as = v_f^2 - v_i^2\\[/tex]
where,
a = acceleration = ?
s = distance covered = compression = 8.5 cm = 0.085 m
vf = final speed = 0 m/s
vi = iniial speed = 10 m/s
Therefore,
[tex]2a(0.085\ m) = (0\ m/s)^2-(10\ m/s)^2\\a = - 588.23\ m/s^2[/tex]
negative sign hows deceleration.
Now, we will calculate the force exerted by the hand:
[tex]F = ma = (7\ kg)(588.23\ m/s^2)\\[/tex]
F = 4117.64 N
Help please:A boy weighing 30 kg rides a scooter. The total kinetic energy of the boy and the scooter is 437.6 J. Determine the speed at which the boy moves if the mass of the scooter is 5kg?
Answer:
5 m/s
Explanation:
Mass of the boy + scooter system = 35 kg
Kinetic Energy = 437.6 J
437.6 = [tex]\frac{1}{2} 35 {v}^2[/tex]
25.0057143 = [tex]v^{2}[/tex]
v = 5 m/s
Which of the following statements is true for a ball thrown vertically upward
discuss impact of Newton's second law on roads
Answer:
The second law: When a force is applied to a car, the change in motion is proportional to the force divided by the mass of the car. This law is expressed by the famous equation F = ma, where F is a force, m is the mass of the car, and a is the acceleration, or change in motion, of the car
You hold an object up with a spring scale and it reads 5N.
What is the mass of the object?
Answer:
balance
Explanation:
Which object is an example of a mechanical wave?
A. light from a flashlight
B. microwaves used to heat food
C. police siren
D. sunlight
Answer:
C.
Explanation:
Hope It Helps
brainliest please
Answer:
C. police siren
Explanation:
Sound waves are mechanical waves
A uniform electric field, with a magnitude of 449 N/C, is directed parallel to the positive x-axis. If the potential at x= 4.59 m is 966 V, what is the potential at x= 1.61 m?
Answer:
2.334 kV
Explanation:
Since the electric field strength Ecosθ = -ΔV/Δx = -(V₂ - V₁)/(x₂ - x₁)
where V₁ = potential at x₁ = 966 V, x₁ = 4.59 m, V₂ = potential at x₂ = unknown, x₂ = 1.61 m and θ = angle between E and the x - axis.
Given that E = + 449 N/C and since it is directed parallel to the positive x - axis, θ = 0°
So,
Ecosθ = -ΔV/Δx
Ecos0° = -ΔV/Δx
E = -ΔV/Δx
E = -(V₂ - V₁)/(x₂ - x₁)
making V₂ subject of the formula, we have
-E(x₂ - x₁) = V₂ - V₁
-E(x₂ - x₁) + V₁ = V₂
V₂ = V₁ - E(x₂ - x₁)
Substituting the values of the variables into the equation, we have
V₂ = V₁ - E(x₂ - x₁)
V₂ = 966 V - 449 N/C(1.61 m - 4.59 m)
V₂ = 966 V - 449 N/C(-2.98 m)
V₂ = 966 V + 1,338.02 Nm/C
V₂ = 966 V + 1,338.02 V
V₂ = 2,334.02 V
V₂ ≅ 2,334 V
V₂ = 2.334 kV
Utility companies charge by the kilowatt-hour. The number of kilowatt-hours used equals the number of kilowatts multiplied by the number of hours an electrical device was used. How long would it take for a 50-watt fan to use 1 kilowatt-hour of electricity? (Hint: 50 watts = 0.05 kilowatts.)
Answer:
t = 3 minutes
Explanation:
Given that,
Power of fan, P = 50 W
Energy used, E = 1 kWh
We know that,
Energy = Power/time
As, 50 watts = 0.05 kilowatts
So,
[tex]t=\dfrac{P}{E}\\\\t=\dfrac{0.05\ kW}{1\ kWh}\\\\t=0.05\ h[/tex]
or
t = 3 min
So, the required time is equal to 3 minutes.
which apparatus is used to measure mass of a bread
Explanation:
a triple beam balance can measure the mass of one slice of bread
A laser pulse of duration 25 ms has a total energy of 1.4 J. The wavelength of this radiation is
567 nm. How many photons are emitted in one pulse? Let 1 eV = 1.60 x 10-19 J, the mass of
an electron m=9.11 10-31
kg, the speed of light c= 3.00 x 108 m/s, and Planck's constant h
= 4.136 10-15 eV .s.
Answer:
n = 4 x 10¹⁸ photons
Explanation:
First, we will calculate the energy of one photon in the radiation:
[tex]E = \frac{hc}{\lambda}\\\\[/tex]
where,
E = Energy of one photon = ?
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of radiation = 567 nm = 5.67 x 10⁻⁷ m
Therefore,
[tex]E = \frac{(6.625\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{5.67\ x\ 10^{-7}\ m}[/tex]
E = 3.505 x 10⁻¹⁹ J
Now, the number of photons to make up the total energy can be calculated as follows:
[tex]Total\ Energy = nE\\1.4\ J = n(3.505\ x\ 10^{-19}\ J)\\n = \frac{1.4\ J}{3.505\ x\ 10^{-19}\ J}\\[/tex]
n = 4 x 10¹⁸ photons
Which two structures are not found in animal cells?
A) vacioles and ribosomes
B) chloroplasts and ribosomes
C) cell walls and chloroplasts
D) endoplasmic reticulum and cell walls
Answer:
C
Explanation:
So, lets start off by thinking about what we know is in both cells, and rule out from there.
There are just some basic things you need in eukaryotic cells, those include the following:
Nucleuscell membranemitochondriacytoplasm(dont get confused with chloroplast)Rough and smooth endoplasmic reticulumGolgi vescileGolci apparatusNucleolus(Dont get confused with nulceus)Here are jsut a few examples of what can be found in both plant and animal cells, however we can already rule out all of the following except for:
C
Because remember, c talks about the chlorplast, which is not the chlorplasm found in both plant anf animal cells, its just the chloroplast found in plant cells.
Although I gave the asnwer to you. Here are some things that are in plant cells that arent in animal cells:
Cell wallvaciolescentral vaciolechlroplastplastidsAnimal cells on the other hand, have a few things that plant cells do not as well:
LysomeCentrolsomeHope this helps! ;)
What is a mechanical advantage?
Answer:
B
Explanation:
A Mechanical Advantage is when you use a piece of machinery to help you do work, and it is an easy advantage.
Suppose you needed to push a 1,500-N sofa up a frictionless ramp with a 30° angle. How much force would you have to apply to the sofa?Show your work below.
Answer:
1299N
Explanation:
GIven data
Weight W= 1500N
Angle Ф= 30°
The applied force up the frictionless ramp is gotten by applying the formula below
F= WcosФ
substitute
F=1500 cos 30
F = 1500*0.8660
F= 1299N
Hence the applied force is 1299N
How can you make two objects with different masses move the same distance
Answer:
apply more energy to the object with more mass
Explanation:
Why are solar storms a concern to Earth?
A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.
Answer:
B.) a wheel and axle and a lever
Explanation:
P.S - The exact question is -
Given - A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.
To find - Which simple machines make up a wheelbarrow?
A.) a pulley and an inclined plane
B.) a wheel and axle and a lever
C.) a pulley and a wheel and axle
D.) a lever and a wedge
Proof -
The correct option is - B.) a wheel and axle and a lever
Wheelbarrows are used to carry more goods from place to place by using minimal force as compared when goods are carried by hand.
With this machine, During hauling people can save time.
Answer:
B.) a wheel and axle and a lever
Explanation:
this questions pls help
Answer:
1. True
2. False
3. True
4. True
5. False
A 200kg bumper car moving 3 m/s collides head on with a 392kg bumper car moving 6m/s. After impact, the larger car continues traveling in the same direction with a velocity of 1.6 m/s . Determine the speed of the other car.
Answer:
the final speed of the smaller car is 5.624 m/s
Explanation:
Given;
mass of the small car, m₁ = 200 kg
initial velocity of the small car, u₁ = 3 m/s
mass of the larger car, m₂ = 392 kg
initial velocity of the larger car, u₂ = 6 m/s
final velocity of the larger car, v₂ = 1.6 m/s
let the direction of the larger car be positive
let the direction of the smaller car be negative
Apply the principle of conservation of linear momentum to determine the final speed of the smaller car.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
200(-3) + 392(6) = 200v₁ + 392 x 1.6
-600 + 2352 = 200v₁ + 627.2
1752 = 200v₁ + 627.2
1752 - 627.2 = 200v₁
1124.8 = 200v₁
v₁ = 1124.8/200
v₁ = 5.624 m/s
Therefore, the final speed of the smaller car is 5.624 m/s
If a cart at the top of a hill has 50 newtons of pot. energy what will it have when it comes down?
Answer:
50 newtons of kenetic energy?? im guessing ngl
Explanation:
The kinetic theory describes the __1__ of particles in matter and the forces of attraction between them. The theory assumes that the volume occupied by a gas is mostly __2__, that the particles of gas are relatively __3__, move __4__ of each other, and are in constant __5__ motion. The __6__ between particles are perfectly elastic so that the total __7__ remains constant. Gas pressure results from the simultaneous collisions of billions of particles with an object. Barometers are used to measure __8__ pressure. Standard conditions are defined as a temperature of __9__ and a pressure of __10__.
Answer:
1. Motion
2. Empty space
3. Far apart
4. Independently
5. Random or rapid
6. Collision
7. Kinetic energy
8. Atmospheric
9. 273 Kelvin or 0° Celsius
10. 1 atm, 101.3 kPa or 760 mmHg
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are;
I. Gas.
II. Solid.
III. Liquid.
Filling the missing words or texts in the question, we have;
The kinetic theory describes the motion of particles in matter and the forces of attraction between them. The theory assumes that the volume occupied by a gas is mostly empty space, that the particles of gas are relatively far apart, move independently of each other, and are in constant random or rapid motion. The collision between particles are perfectly elastic so that the total kinetic energy remains constant. Gas pressure results from the simultaneous collisions of billions of particles with an object. Barometers are used to measure atmospheric pressure. Standard conditions are defined as a temperature of 273 Kelvin or 0° Celsius and a pressure of 1 atm, 101.3 kPa or 760 mmHg.
a) How is the single covalent bond usually shown in each diagram?
In a car collision, is it better for the passenger if the change in momentum is over a short period of time or a long period of time?
Explanation:
The force on the passenger will be F = ma
Here, m does not change, but a is the variable.
If the cars slows down very fast, the acceleration will be higher, and thus the force will be higher.
If the acceleration is lower, the force will be lower as well, which would be the most desirable scenario for the passenger.
Help Me!! 50pts
It will mean a lot
Explanation:
full moon
Maria's mother was deported 6 months ago, and she is staying with a cousin. She has to share a room with 3 other children and is very discouraged. She has little energy to do much of anything, and she cries a lot. She is probably suffering from?
She is probably suffering from a major depression. Depression results in emotional change and loss of interest in previously appreciated activities.
What is depression?Depression is a frequent and significant medical ailment that has an adverse effect on how you feel, think, and act. It can cause a number of mental and physical difficulties, as well as a loss in your ability.
According to epidemiological research, a hereditary element is involved in 30% to 40% of instances of bipolar illness. As a result, environmental influences have a larger role in the development of depression.
Maria's mother was deported 6 months ago, and she is staying with a cousin. She has to share a room with 3 other children and is very discouraged.
She has little energy to do much of anything, and she cries a lot, she is probably suffering from a major depression.]
Hence, option A is correct.
To learn more about the depression, refer to the link;
https://brainly.com/question/9790235
#SPJ2
heena wants to measure the volume of a ball that is 24 cm across. How should she set up her equation? v = one-third pi 24 squared (12). v = one-third p 12 squared (24). v = four-thirds pi 24 cubed. v = four-thirds pi 12 cubed.
Answer:
v = four-thirds pi 12 cubed.
Explanation:
A ball has a spherical shape. The volume of a spherical shape can be calculated using the following formula:
[tex]V = \frac{4}{3} \pi r^3[/tex]
where,
V = Volume of Ball = ?
d = diameter of the ball = length across the ball = 24 cm
r = radius of ball = d/2 = 24 cm/2 = 12 cm
Therefore,
[tex]V = \frac{4}{3}\pi (12)^3[/tex]
Hence, the correct answer is:
v = four-thirds pi 12 cubed.
GIVING BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 25pts-
Answer:
b and d :)
Explanation:
Answer:
A, B, And C,
Explanation:
The law of conservation of energy is a physical law that states energy cannot be created or destroyed but may be changed from one form to another. Another way of stating this law of chemistry is to say the total energy of an isolated system remains constant or is conserved within a given frame of reference.