Answer:
A. Mg+2
Explanation:
im not sure, but since it lost two electrons which have a negative charge it gained two charge.
Temperature of substance changes from -20 celsius to 20 celsius. What is temperature change in kelvin scale
Answer:
313kelvin
Explanation:
40 degree celcius plus 273=313K
what is gravity..
what is force.
mention the two type of force
and give 3,3 exmples
Answer:
Oh, umm…
Jump! (The higher, the better!)
Drop your pencil! (or pen or ruler, whichever you prefer!)
Throw a ball of paper! (and make sure you pick it back up later!)
Explanation:
if you satisfied to my answer , just put brainliest please , and ur welcomeee♥️♥️
What is energy and what is the formula of energy
Answer:
Energy is: the ability to do work
The formula for energy is: power x time = energy
Explanation:
Hope this helps (there isn't really an explanation)
A road with a radius of 75.0 m is banked so that a car can navigate the curve at a speed of 15.0 m/s without any friction. When a car is going 31.8 m/s on this curve, what minimum coefficient of static friction is needed if the car is to navigate the curve without slipping?
Find the angle θ made by the road. When rounding the curve at 15.0 m/s, the car has a radial acceleration of
a = (15.0 m/s)² / (75.0 m) = 3.00 m/s²
There are two forces acting on the car in this situation:
• the normal force of the road pushing upward on the car, perpendicular to the surface of the road, with magnitude n
• the car's weight, pointing directly downward; its magnitude is mg (where m is the mass of the car and g is the acceleration due to gravity), and hence its perpendicular and parallel components are, respectively, -mg cos(θ) and mg sin(θ)
By Newton's second law, the net forces in the perpendicular and parallel directions are
(perp.) ∑ F = n - mg cos(θ) = 0
(para.) ∑ F = mg sin(θ) = ma
==> sin(θ) = a/g ==> θ = arcsin(a/g) ≈ 17.8°
(Notice that in the paralell case, the positive direction points toward the center of the curve.)
When rounding the curve at 31.8 m/s, the car's radial acceleration changes to
a = (31.8 m/s)² / (75.0 m) ≈ 13.5 m/s²
and there is now static friction (mag. f = µn, where µ is the coefficient of static friction) acting on the car and keeping from sliding off the road, hence pointing toward the center of the curve and acting in the parallel direction. Newton's second law gives the same equations, with an additional term in the parallel case:
(perp.) ∑ F = n - mg cos(θ) = 0
(para.) ∑ F = mg sin(θ) + f = ma
The first equation gives
n = mg cos(θ)
and substituting into the second equation, we get
mg sin(θ) + µmg cos(θ) = ma
==> µ = (a - g sin(θ)) / (g cos(θ)) = a/g sec(θ) - tan(θ) ≈ 1.12
Answer:
Explanation:
You are in the chapter on Physics about uniform circular motion and gravity. This is a centripetal force problem in particular, and the equation for that is
[tex]F_c=\frac{mv^2}{r}[/tex] where
[tex]F_c[/tex] is the centripetal force needed to keep the car moving in its circular path,
m is the mass of the car,
v is the velocity with which the car is moving, and
r is the radius of the circle that the car is moving around.
For us, the centripetal force is supplied by the friction keeping the car on the road, altering the equation to become
[tex]f=\frac{mv^2}{r}[/tex] and friction is defined by
f = μ[tex]F_n[/tex] (the coefficient of friction multiplied by the weight of the car).
Going on and getting buried even deeper,
[tex]F_n=mg[/tex] which says that the weight of the car is equal to its mass times the pull of gravity. Putting all that together, finally, we have the equation we need to solve this problem:
μ·m·g = [tex]\frac{mv^2}{r}[/tex] and we solve this for μ:
μ = [tex]\frac{mv^2}{mgr}[/tex] and it just so happens that the mass of the car cancels out. (I'll tell you why the mass of the car doesn't matter at the end of this problem). Filling in and solving for the coefficient of friction:
μ = [tex]\frac{31.8^2}{(9.8)(75.0)}[/tex] to 2 significant figures is
μ = 1.4
The mass of the car doesn't affect whether or not the car can stay on the curve. Even though a car with a greater mass will have a greater frictional force, that doesn't mean that it's easier for that car to stay on the road; a larger mass only means that a larger centripetal force is needed to keep it moving in a circle. This makes the gain in friction become offset by the fact that a larger centripetal force is necessary. Thus,
On a flat curve, the mass of the object experiencing circular motion does not affect the velocity at which it can stay on the curve.
When you flip a penny (2.35 g), it leaves your hand and moves upward at 2.85 m/s. Use energy to find how high the penny goes above your hand before stopping. A (b) The penny then falls to the floor, 1.26 m below your hand. Use energy to find its speed just before it hits the floor. A (c) Explain your choice of reference level for parts (a) and (b). C (d) Choose a different reference level and repeat part (b)
Answer:
a. 0.41 m
b. 5.72 m/s
c. i. For part (a), I chose the hand as the reference level since the penny was thrown from the hand and the height of the penny at the hand is zero and also, it is easier to calculate from a zero reference level.
ii. For part (b), I chose the ground as the reference level since the height of the penny above the ground is positive and the height of the penny when the penny hits the ground is zero and also, it is easier to calculate from a zero reference level.
d. 5.72 m/s
Explanation:
a. Use energy to find how high the penny goes above your hand before stopping.
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy at the hand, E equals the total mechanical energy when the penny stops in the air, E'.
E = E'
U + K = U' + K' where U = initial potential energy at hand level = mgh where h = height at hand level = 0, K = initial kinetic energy at hand level = 1/2mv² where v = speed at hand level = 2.85 m/s, U' = final potential energy at stopping level = mgh' where h' = height at stopping level, K = final kinetic energy at stopping level = 1/2mv'² where v = speed at stopping level = 0 m/s (since the penny momentarily stops)
So, U + K = U' + K'
mgh + 1/2mv² = mgh' + 1/2mv'²
substituting the values of the variables into the equation, we have
mg(0) + 1/2m(2.85 m/s)² = mgh' + 1/2m(0 m/s)²
0 + 1/2m(8.1225 m²/s²) = mgh' + 0
m(4.06125 m²/s²) = mgh'
h' = 4.06125 m²/s² ÷ g
h' = 4.06125 m²/s² ÷ 9.8 m/s²
h' = 0.41 m
(b) The penny then falls to the floor, 1.26 m below your hand. Use energy to find its speed just before it hits the floor.
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy when the penny stops in the air, E' equals the total mechanical energy on the ground, E"
E' = E"
U' + K' = U" + K" where U' = initial potential energy at stopping level = mgh" where h' = height at stopping level = height of penny above hand, h' + height of hand above ground = 0.41 m + 1.26 m = 1.67 m, K = initial kinetic energy at stopping level = 1/2mv'² where v = speed at stopping level = 0 m/s (since the penny momentarily stops), U = final potential energy at ground level = mgh₁ where h₁ = height at ground level = 0, K = final kinetic energy at ground level = 1/2mv"² where v" = speed at ground level,
So, U' + K' = U' + K'
mgh" + 1/2mv'² = mgh₁ + 1/2mv"²
substituting the values of the variables into the equation, we have
mg(1.67 m) + 1/2m(0 m/s)² = mg(0) + 1/2mv"²
1.67mg + 0 = 0 + 1/2mv"²
1.67mg = 1/2mv"²
1.67g = 1/2v"²
v"² = 2(1.67g)
v" = √[2(1.67g)]
v" = √[2(1.67 m × 9.8 m/s²)]
v" = √[2(16.366 m²/s²)]
v" = √[32.732 m²/s²)]
v" = 5.72 m/s
(c) Explain your choice of reference level for parts (a) and (b).
i. For part (a), I chose the hand as the reference level since the penny was thrown from the hand and the height of the penny at the hand is zero and also, it is easier to calculate from a zero reference level.
ii. For part (b), I chose the ground as the reference level since the height of the penny above the ground is positive and the height of the penny when the penny hits the ground is zero and also, it is easier to calculate from a zero reference level.
(d) Choose a different reference level and repeat part (b)
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy when the penny stops in the air, E' equals the total mechanical energy on the ground, E"
E' = E"
U' + K' = U" + K" where U' = initial potential energy at stopping level = mgh' where h' = height at stopping level = 0.41 m, K = initial kinetic energy at stopping level = 1/2mv'² where v' = speed at stopping level = 0 m/s (since the penny momentarily stops), U = final potential energy at ground level = mgh₁ where h₂ = height of hand above the ground level = height of ground below hand = -1.26 m(it is negative since the ground is below the hand), K = final kinetic energy at ground level = 1/2mv"² where v = speed at ground level,
So, U' + K' = U' + K'
mgh' + 1/2mv'² = mgh₂ + 1/2mv"²
substituting the values of the variables into the equation, we have
mg(0.41 m) + 1/2m(0 m/s)² = mg(-1.26 m) + 1/2mv"²
0.41mg + 0 = -1.26 mg + 1/2mv"²
0.41mg + 1.26mg = 1/2mv"²
1.67mg = 1/2mv"²
1.67g = 1/2v"²
v"² = 2(1.67g)
v" = √[2(1.67g)]
v" = √[2(1.67 m × 9.8 m/s²)]
v" = √[2(16.366 m²/s²)]
v" = √[32.732 m²/s²)]
v" = 5.72 m/s
10.
You are standing on a sheet of ice that covers the football stadium parking lot in Buffalo; there is
negligible friction between your feet and the ice. A friend throws you a 0.4 kg ball that is traveling
horizontally at 10 m/s. Your mass is 70 kg. If you catch the ball, with what speed do you and the ball
move afterwards?
1.02 m/s
0.06 m/s
0.02 m/s
0.12 m/s
Answer:
Explanation:
This is a classic Law of Momentum Conservation problem. For us the equation will look like this:
[tex][(m_yv_y+m_bv_b)]_b=[(m_y+m_b)v_{both}]_a[/tex] Filling in with our given info:
[tex][(70.0)(0)+(.40)(10.0)]_b=[(70.0+.40)v_{both}]_a[/tex] and
4.0 = 70.4v and
v = .06 m/s
A fixed mass of gas has a volume of gas of 25cm3. the pressure of the gas is 100kPA. the volume of the gas is slowly decreased by 15cm3 at a constant temperature. what is the change in the pressure of the gas?
a) 67kPA
b) 150kPA
c) 170kPA
d) 250kPA
give reasons
A fixed mass of gas has a volume of 25 [tex]cm^3[/tex], the pressure of the gas is 100 kPa, the volume of the gas is slowly decreased by 15 [tex]cm^3[/tex] at a constant temperature, and the change in pressure of the gas is 150 kPa, which is option b.
What is the calculation of the change in pressure?PV = nRT (P= pressure of the gas, V =volume, n = number of moles of gas, R = gas constant, and T =temperature of the gas in kelvin)
Suppose the gas is an ideal gas and that the temperature is constant,
P1V1 = P2V2
Here P1 = 100 kPa, V1 = 25 [tex]cm^3[/tex], V2 = 10 [tex]cm^3[/tex],
100 kPa x 25 [tex]cm^3[/tex] = P2 x 10 [tex]cm^3[/tex]
P2 = (100 kPa x 25 [tex]cm^3[/tex]) / 10 [tex]cm^3[/tex]
P2 = 250 kPa
the change in pressure of the gas is,
ΔP = P2 - P1 = 250 kPa - 100 kPa = 150 kPa
The reason is that when the volume of a fixed mass of gas is decreased, the pressure of the gas increases proportionally, so here assuming that the temperature is constant it is calculated.
Hence, the volume of the gas is slowly decreased by 15 [tex]cm^3[/tex] at a constant temperature, and the change in pressure of the gas is 150 kPa, which is option b.
Learn more about the calculation of the change in pressure here.
https://brainly.com/question/15938504
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What is the gravitational force between two objects?
Answer:
Gravitational force -an attractive force that exists between all objects with mass; an object with mass attracts another object with mass; the magnitude of the force is directly proportional to the masses of the two objects and inversely proportional to the square of the distance between the two objects.
Explanation:
hope it helped
How does an electric bulb work?
this is a class 6 question...
Answer:
Explanation:
When a light bulb connects to an electrical power supply, an electrical current flows from one metal contact to the other. As the current travels through the wires and the filament, the filament heats up to the point where it begins to emit photons, which are small packets of visible light.
A force of 20000N acts on the raft in the direction down
State the name given to the force shown by arrow in Fig.
Calculate the mass of the raft.
Answer:
Figure is not there
Explanation:
1o4 Fahrenheit is equal to
Answer:
40 degrees Celsius
Explanation:
Have a great summer :)
Two friends are working out together using weights:
-James lifts 20kg weights up at a velocity of 1.9m/s
-Kayla lifts 15kg weights up at a velocity of 2.6m/s
0
Which friend is creating more momentum?
Answer:
Kayla. You can calculate it using the formula for momentum: momentum=mass×velocity and find the bigger number between the two momentums
Number of conducting plates of a multiplate capacitor is 5. The no. Of capacitors is
A.1
B.2
C.3
D.4
(Ans with explanation pls)
Answer:
4 capacitors
Explanation:
Given
[tex]n = 5[/tex] --- conducting plates
Required
The number of capacitor (c)
This is calculated as:
[tex]c = n - 1[/tex]
So, we have:
[tex]c = 5 - 1[/tex]
[tex]c = 4[/tex]
When the interval between the stimuli decreases, _______.
A. a second action potential is generated until the interval reaches the absolute refractory period
B. a second action potential is generated regardless of the stimulus and the interval
C. a second action potential is generated until the interval reaches the relative refractory period
D. a second action potential is generated as long as the stimulus is above threshold
Answer:
The correct option is A. a second action potential is generated until the interval reaches the absolute refractory period.
Explanation:
The inter-stimulus interval (ISI) is the temporal interval between two successive stimuli, measured from the offset of the first stimulus to the commencement of the second.
A cell's refractory period is the time during which it is unable to replicate an action potential. Therefore, the absolute refractory period is the amount of time it takes for a second action potential to be initiated, regardless of how large a stimulus is applied repeatedly.
A second action potential is generated when the gap between the stimuli decreases until the interval reaches the absolute refractory period.
Therefore, the correct option is A. a second action potential is generated until the interval reaches the absolute refractory period.
That is, when the interval between the stimuli decreases, a second action potential is generated until the interval reaches the absolute refractory period.
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
what two forces contribute to the nuclear tug of war in an atom
Answer:2 protons and 2 neutrons
Explanation:In Nuclei, There are 2 forces. 1 force is electrostatic and acts as repulsion between 2 protons. The other is force of attraction called Nuclear force between 2 neutrons.
Find the acceleration a body whose velocity increases from 11m/s to 33m/s in 10 seconds
Answer:
I am not sure if this is the answer
acceleration: 2.2m/s
Explanation:
here
initial velocity(u): 11m/s
Final velocity(v): 33m/s
time taken(t): 10 s
now
a:v-u/t
or
acceleration:final velocity-initial velocity/time taken
or
a: 33-11/10
or
a:22/10, divide it
: a=2.2m/s#
I need this now
On the planet Xenos, an astronaut observes that a 2.0 m long pendulum has a period of 2.2 s.
What is the free-fall acceleration on Xenos? *
Answer:
[tex]g=16.31\ m/s^2[/tex]
Explanation:
Given that,
The length of the pendulum, l = 2 m
The period of the pendulum, T = 2.2 s
The formula for the time period of a pendulum is given by :
[tex]T=2\pi \sqrt{\dfrac{l}{g}}[/tex]
or
[tex]T^2=4\pi ^2\dfrac{l}{g}\\\\g=\dfrac{4\pi ^2l}{T^2}\\\\g=\dfrac{4\pi ^2\times 2}{(2.2)^2}\\\\g=16.31\ m/s^2[/tex]
So, the free fall acceleration is [tex]16.31\ m/s^2[/tex].
explain how conservation of mechanical energy occurs a kicking a ball
If the car falls down the side of the cliff, what is happening to the gravitational potential energy of the falling car (Assume the bottom of the cliff is zero)
Group of answer choices
the gravitational potential energy is decreasing
the gravitational potential energy has not changed
the gravitational potential energy is increasing
Explanation:
Gravitational potential energy is energy an object possesses because of its position in a gravitational field. ... The gravitational potential energy is equal to its weight times the height to which it is lifted. PE = kg x 9.8 m/s2 x m = joules. The 9.8 us the gravitational acceleration constant.
so the answer is "the gravitational potential energy is decreasing"
A woman pushes a car with a force of 400 N for a distance of 15m. How much work has she done?
Answer:
the work done by the woman is 6,000 J
Explanation:
Given;
force applied by the woman, F = 400 N
distance moved by the woman, d = 15 m
The work done by the woman is calculated as follows;
W = F x d
W = 400 N x 15 m
W = 6000 Nm = 6,000 J
Therefore, the work done by the woman is 6,000 J
Scientists have developed a new type of solar cell with an efficiency of over 40 %.
The efficiency of the solar cell was confirmed independently by other scientists.
Suggest why it was important to confirm the efficiency independently.
Answer:
According to Carl Sagan's Baloney Detection Kit notes
"Whenever possible there must be independent confirmation of the facts"
Independent confirmation by other scientist is to ensure that the observation of the over 40% efficient solar panel is repeatable
It is also important to avoid accepting the given mandates at face value and accepting that the scientist considered all factors when taking the results or that the original developers has assigned others to check their findings before the introduction of the new type of solar cell
Explanation:
calculate:An elcetric lamp is rated 240V and 40W. What is the cost of running the lamp for 62 hours if the elctricity authorities charges #2.50k per KWH
Explanation:
The voltage of the lamp, V = 240 V
Power of the lamp, P = 40 W
It is running for 62 hours.
The cost of running is $2.50k per KWH
Electric power is,
P = 40×62 Wh
= 2480 Wh
P = 2.48 kWh
At the rate of $2.5 per kWh
P = $6.2
So, the cost of running is $6.2 per kWh.
.If a vehicle covers 3 km in 5 minutes, calculate the speed of the vehicle? (With process )
Answer:
Speed = 1.6 m/s
Explanation:
Formula,
Speed = Distance ÷ Time
what is fundamental
Fundamental
forming a necessary base or core; of central importance.
"the protection of fundamental human rights"
A.All three bulbs will go out
B.Bulbs 2 and 3 will go out, but bulb 1 will remain lit
C. All three bulbs will go out
D. Bulb 3 will go out, but bulbs 1 and 2 remain lit
Answer:
(D)
Explanation:
When switch C is opened then, Current is not flowing across 3 So bulb 3 will go out.
But current is flowing across 1 and 2 bulb because their switch is closed
therefore bulb 1 and 2 will remain it.
Hence, option (D) will be correct.
6) A car of mass 1000kg moving with a velocity of 40m/s collides with a tree and comes to stop in 5s. What will be the force exerted by the car on the tree?
Answer:
Refer to the attachment!~
You throw a water balloon straight up with a velocity of 13 m/s. What is its
maximum height?
O A. 4.4 m
B. 6.3 m
C. 10.7 m
D. 8.6 m
Answer:
Explanation:
[tex]h=-v^2 /2g[/tex]
[tex]with\\g = 9,8 m/s^2 or 10 m/s^2[/tex]
[tex]h= (-13)^2 / 2 * 9,8 = 8,6[/tex]
En el proceso de diseño de ingeniería, ¿qué limitaciones deben tenerse en cuenta al utilizar un modelo / prototipo?
Answer:
Las limitaciones de un modelo o prototipo son;
1) Los parámetros ambientales (donde se opera el modelo, prototipo o producto) son diferentes y, por lo tanto, pueden producir relaciones y factores ambientales que serán diferentes de los factores ambientales y las relaciones del objeto real.
2) El análisis del problema puede ser inadecuado
3) La posibilidad de falta de satisfacción del cliente con un modelo, preferencia por la demostración real del producto.
4) Reproducción inexacta del entorno del producto durante la prueba del modelo
5) El factor de costo del modelo
6) Mayor complejidad introducida por el modelo / prototipo al análisis de la solución
Explanation:
El modelo o prototipo es la presentación del diseño articulado, construido para demostrar el producto real con el propósito de encontrar la existencia de errores en el diseño que serían corregidos, antes de que se realice la producción real
DEFINE UNIFORM AND NON UNIFORM VELOCITY
Explanation:
Uniform velocity is when an object goes an equal amount of space in an equal amount of time whereas non uniform velocity is when the object covers an unequal amount of distance in an equal amount of time.