If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s

Answer:

Explanation:

There is no pressure of your feet on the scales, and no pressure of the floor on the scales, so the scales will read zero*. Hence, your weight, in a freely falling lift is zero

Answer:

12000gram

Explanation:

1kg=1000gram

so, 12kg=12x1000

12kg=12000gram

Given amount=12kg

[tex]\boxed{\sf 1kg=1000g}[/tex]

[tex]\\ \sf\longmapsto 12kg=12(1000)[/tex]

[tex]\\ \sf\longmapsto 12kg=12000g[/tex]

Lithium element contains one electron therefore valence electron will be one.  

The highest level of energy is due to valence electrons which are available to the atom.

The calcium has 2 valence electrons which has electrons with high energy.

These energy will be used by the electron during the chemical reaction, and they will either lose or gain valence electron.

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Answer:

calcium

Explanation:

2 electron

Answer: i think c

Explanation:QA: “What is ordinary glass made of ?”

Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.

“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C

Answer with Explanation:

Let me answer this in a simple way, since the density of stone is greater than that of water, the stone sinks as the weight of the stone is greater than the weight of water displaced by it. But the ship is designed in such a way that the relative density of the ship always becomes less than that of water. Therefore, the weight of the water displaced becomes equal to the total weight of the ship and thus it floats.

There are many other ways to explain this but this should give you the general idea.

Answer:

Energy production requires the setting up of a complete interconnected chain from generation of energy from the root source of the energy to the storage of the generated energy and the eventual utilization of the energy when required

Solar energy, indirectly, continues to be the main source of energy, however, the direct use of solar energy to power the systems we use in our everyday life, require the development of technologies, such as high efficiency solar cells, means of energy storage, and compatible efficient energy usage which are industrial areas that are seeing good progress but in which the current developed equipment are expensive to produce, and  due to their efficiency, are undergoing further research and development

Therefore, due to the continuous increasing improvement in solar technology which can observed, the use of the produced energy through solar is evolving, and therefore, will continue to play a continuously increasing but lower role compared to other sources of energy which have been developed to satisfactory level that can drive an industry, considering the financial investment involved

Explanation:

Answer:

D. water

Explanation:

sugar ( glucose ) and oxygen are bi-products

Answer:

(d) water

Explanation:

water is required for photosynthesis to take place .

sugar , oxygen , ATP are not required to take place in photosynthesis.

Answer:

Explanation:

A plane mirror is the kind you look into when you look into a "regular" mirror. The image you see is right-side-up. These images are virtual. Real images are always upside down and are made by mirrors that are "parabolic" in shape. Virtual images are always right-side-up.

Answer:D.Keeping track of the exact amount of wind on each plant

Answer:

a). Silver, Ag

b). Iron, Fe

c). Copper, Cu

d). Aluminium, Al

e). Gold, Au

Answer:

If effort distance was 4 times, efficiency would be 100%.

Since it takes 5 times for effort distance, efficiency drops to output/input

output is 1*F

input is (1/4*F)*5

so: F/1/5*F/4 = 4F/5F = .8 or 80%

The efficiency of the lever is 80%.

To calculate the efficiency of the lever, we can use the formula for mechanical advantage and efficiency.

Mechanical Advantage (MA) is the ratio of the load (L) to the effort (E) in a lever system:

MA = Load / Effort

Given that the load is four times the effort applied:

Load = 4 * Effort

Also, the effort distance (dEffort) is five times the load distance (dLoad):

dEffort = 5 * dLoad

Now, we can write the formula for efficiency (η) of a lever system:

Efficiency (η) = (Mechanical Advantage / Ideal Mechanical Advantage) * 100%

The Ideal Mechanical Advantage (IMA) is the ratio of the effort distance to the load distance:

IMA = dEffort / dLoad

Substitute the given values into the IMA equation:

IMA = (5 * dLoad) / dLoad

IMA = 5

Now, we can calculate the Mechanical Advantage (MA) using the relationship between the load and effort:

MA = Load / Effort

MA = (4 * Effort) / Effort

MA = 4

Finally, we can calculate the efficiency (η):

Efficiency (η) = (Mechanical Advantage / Ideal Mechanical Advantage) * 100%

η = (4 / 5) * 100%

η = 0.8 * 100%

η = 80%

The efficiency of the lever is 80%.

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Answer:

0.80 m

Explanation:

Neglecting friction, the total mechanical energy of the pendulum is constant.

E = K + U where K = kinetic energy and U = potential energy.

At its release point of 0.80 m, the pendulum bob has a mechanical energy which is equal to its potential energy, since, its initial kinetic energy is zero. By the time the bob swings to the other end, it has a mechanical energy equal to it initial potential energy since total energy is conserved.

Neglecting friction, the pendulum bob would swing back to its original height of 0.80 m since the total mechanical energy is conserved and at its highest point, it is purely potential energy.

So, the height the pendulum bob swings to after release from a height of 0.80 m neglecting fiction is 0.80 m.

Answer:

good

Explanation:

Answer:

fine

Explanation:

make me as brainliast

Answer:

But negative acceleration means that the rate of change of velocity is negative or velocity decreases. Example: (1) When we apply brakes in a moving car, then negative acceleration acts on it and the car stops. (2) When we throw a ball upwards, then also negative acceleration acts on it.

Explanation:

If it helps you mark me as a brainleast

MATHEMATICALLY A NEGATIVE ACCELERATION MEANS YOU WILL SUBTRACT FROM THE CURRENT VALUE OF THE VELOCITY.

Answer:

False -> negative charge

Answer:

false

Explanation: electrons are negative charges

protons are positive charges

Answer:

1) The kinetic energy of the object after it drops for 2.0 seconds is approximately 384.9 Joules

2) The potential energy of the object after it drops for 2.0 seconds is approximately 204 J

Explanation:

1) The given mass of the object, m = 2.0 kg

The height from which the object is dropped, h = 30 m

The kinetic energy of the object after it drops for 2.0 seconds = Required

Kinetic energy, K.E. = (1/2)·m·v²

Where;

v = The velocity of the object

The kinematic equation for finding the velocity of the object is presented as follows;

v = u + g·t

Where;

u = The initial velocity of the object = 0

g = The acceleration due to gravity of the object ≈ 9.81 m/s²

t = The time of motion of the object = 2.0 seconds

∴ The velocity after 2 seconds, v ≈ 0 + 9.81 m/s² × 2 s = 19.62 m/s

The kinetic energy, K.E. after 2 seconds as the object drops is given as follows;

[tex]K.E._{(after \ two \ seconds)}[/tex] = (1/2) × 2.0 kg × (19.62 m/s)² = 384.9444 J ≈ 384.9 J

2) The total energy, M.E. of the object at the top, h = 30 m, u = 0, is given as follows;

The total mechanical energy, M.E. = P.E. + K.E.

M.E. = m·g·h + (1/2)·m·u²

∴ M.E. = 2.0 kg × 9.81 m/s² × 30 m + 0 = 588.6 J

M.E. = 588.6 J

Given that the total mechanical energy, M.E., is constant, we have;

At 2.0 seconds, M.E. = 588.6 J , K.E. ≈ 384.9 J, P.E. = M.E. - K.E.

∴ P.E. = 588.9 J - 384.9 J ≈ 204 J

The potential energy after it drops 2.0 seconds, P.E. ≈ 204 J

Answer:D

Explanation:

Answer:

A simple machine uses a single applied force to do work against a single load force

Ignoring the friction losses. The work done on the load is equal to the work done with the applied energy. The machine can increase the amount of output power, with a corresponding drop in the distance transported by the load.

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Explanation:

Magnetic lines of force are closed curves. C) Outside the magnet their direction is from north pole to south pole and inside the magnet these are from south to north pole.

Answer:

cần cung cấp 70 độ vì nước sôi ở 100°C

Explanation:

Option ( iv ) is the correct answer.

A vector quantity the physical quantity that has both direction as well as magnitude.

We know

[tex]\boxed{\sf Spring\:constant(K)=\dfrac{F}{x}}[/tex]

[tex]\\ \sf\longmapsto K=\dfrac{1}{0.5}[/tex]

[tex]\\ \sf\longmapsto K=2N/m[/tex]

Answer:

True

Explanation:

The bigger an object is, the more force you must apply to move the object. Think about it like moving a mouse compared to moving an elephant. You can't move the elephant by yourself, because you don't have enough strength or force to move it. But, you can easily pick up a mouse, because it requires less force, or strength. Hope this helped :)

Answer:

I don't know

Explanation:

sorry but I will help u next time kk

AnswerIt is continuously falling towards the surface of the earth

Explanation:

since gravity from earth is the thing that keeps it constantly in orbit

Answer:

HOPE IT HELP YOU A LOT :)

I prove it also .

Answer:

Newtons Second law of motion states that"The rate of change of momentum is directly proportional to the force applied"

Answer:

the specific heat capa city of the aluminium is 900 joules per kilogram per °C.

Am I right please?

Answer:

Explanation:

The first part of this question is simply asking us to convert the speed from miles per hour to meters per second:

[tex]60.0\frac{mi}{hr}*\frac{1hr}{3600sec}*\frac{1609.34m}{1mi}=26.8\frac{m}{s}[/tex] choice C.

The next part wants us to use the equation for acceleration and find the acceleration:

[tex]a=\frac{v-v_0}{t}[/tex] where v is final velocity, v0 is initial velocity, and t is time in seconds (which was one of the reasons we had to convert the initial velocity from 60.0 mph to m/s):

[tex]a=\frac{26.8-0}{2.5}[/tex] and

a = 10.7 m/s/s, choice B.

Answer:

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Answer:

25 mm = 0 deg C

200 mm = 100 deg C

200 - 25 = 175 = change in thread per 100 deg C

95 - 25 = 70 mm - change in thread from 0 deg C

70 / 175 * 100 = 40 deg C    final temperature at 95 mm