A train starts from rest. It acquires a speed of 25 m/s after
20 s. The total
distance is
​

Answer:

v =2.02

Explanation:

v^2=0.05-4.9

v^2=-4.85

square root both side

v=2.02

^^^^this is a not a perfect square  

Answer:

Every action has an equal and opposite reaction. If the student doesn't push, nothing moves, is one student pushes, both move which is an example of newtons third law.

Explanation:

Answer:

The vacuum of outer space is not caused by the expansion of the universe, but is caused by gravity.

Explanation:

Answer: Explanation:

If the number of electrons is equal to the number of protons then the atom is uncharged and is electrically neutral. However, atoms can gain or lose electrons: increasing or decreasing the negative charge. Ionisation is the addition or removal of an electron to create an ion. ..Gaining an electron creates a negative ion.

Answer:

B. Thermal energy

E. Sound energy

Explanation:

Thermal and sound energy is kinetic energy.

Kinetic energy is the energy that results as a function of the motion of a body or the particles of the medium.

Sound energy is transmitted by the vibration of the particles in the air. The vibration leads to movement of the particles and hence, kinetic energy is produced.

Thermal energy originates as a result of the temperature differences in a body. This temperature difference leads to the increase in the kinetic energy of some particles which also causes vibration and motion of the particles.

The two options which are forms of kinetic energy include:

Kinetic energy is the form of energy possessed by a body by virtue of its

motion.

Thermal energy possesses kinetic energy as a result of the high

temperature bringing about an increase in the collision of the particles.

Sound energy also possesses kinetic energy as a result of the vibrations

through the movement of energy in a medium.

Read more about Kinetic energy here https://brainly.com/question/8101588

Answer:

Explanation:

I really don’t know

Given that,

The initial speed of a ball, u = 17.3 m/s

It is shot from the roof of a 52 m tall building, h = 52 m

It is required to find the distance from the base of the building the ball land. Let the distance be d.

Final velocity of the ball, v = 0 (when it lands)

We can use third equation of motion to find it.

[tex]v^2-u^2=2ad[/tex]

a = -g

[tex]-u^2=-2gd\\\\d=\dfrac{u^2}{2g}\\\\d=\dfrac{(17.3)^2}{2\times 9.8}\\\\d=15.26\ m[/tex]

So, it will land at a distance of 15.26 m.

Answer:

7 kg

Explanation:

Mass remains the same, regardless of gravity. If the mass of the bowling ball is 7kg on Earth, the mass on the moon will be 7kg as well.

Answer:

Explanation:

1) weight = mg = 9.81*1000 = 9810 Newtons

2) frictional force = normal force *

we must assume that the vehicle is on a flat surface so therefore the normal force is the same as the weight of the vehicle.

frictional force = 9810 * 0.55 = 5 395.5 N

3) acceleration: F = ma, a = F/m

assume that only the frictional force is acting on the vehicle:

a = 5395.5/1000 = 5.3955 m/s

4) the car decelerates at 5.3955m/s

over 6 seconds, the car decelerates by: 32.37m/s

5) original speed = 29m/s final speed = 29-32.37 = -3.37m/s which is a negative number, therefore the vehicle would have stopped before it hit the rail.

6) to get to the rail, the vehicle would have had to be traveling at least 32.37m/s which is 72.41 mph

Explanation:

mark as brainliest plssssssssssssss!

Answer:

Can dissolve

Explanation:

Answer:

The candy before was fluffy, and the candy after was compacted.

Explanation:

By definition, something that is fluffy is something very soft, and when you talk about fluffy food (e.g. cakes, cotton candy) it is food that has a lot of air in it. In this case, the cotton candy originally had the shape of a cloud and was not dense, therefore, it was fluffy.

Something that is compact, it something that is dense, solid and generally small. Since Chanel wanted her cotton candy to be more dense, she compacted it .

Answer:

c

Explanation:

Answer:

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

From the question

average speed = 250 km/h

time = 2 hrs

We have

distance = 250 × 2

We have the final answer as

Hope this helps you

Answer:

The answer would be 454 miles.

Explanation:

You multiply the average speed by time travelled. Hope this helps!

Answer:

Answers in solutions.

Explanation:

Question 6:

The density of gold is 19.3 g/cm³

The density of silver is 10.5 g/cm³

Density = mass ÷ volume = [tex]\frac{1930}{100}[/tex] = 19.3 g/cm³

Since the density of gold, given, is 19.3 g/cm³ and the density of the substance in Crown A has a density of 19.3 g/cm³ , then that substance must be gold.

Density = mass ÷ volume = 1930 ÷ 184 = 10.48913043  g/cm³ ≈ 10.5 g/cm³  (answer rounded up to one decimal place)

Since the density of the substance in Crown B is approximately equal to 10.5 g/cm³ , then that substance is Silver.

Density = mass ÷ volume = 1930g ÷ 150cm³ = 12.86666667 ≈ 12.9 cm³ (answer rounded up to one decimal place)

For 2 cm³ of the mixture, its mass equal 19.3 g + 10.5 g = 29.8 g

∴ for 1 cm³ of the mixture, its mass equal to [tex]\frac{29.8}{2}[/tex] = 14.9 g

Hence the density of the mixture = 14.9 g/cm³ and is not equal to the density of the substance in Crown C.

* Crown C is not made up of a mixture of gold and silver.

Question 7:

The mass of water that occupied the 100 cm³ space of the container = total mass - mass of the empty container = 850 g - 500 g = 350 g

Density of the liquid (water) poured into the container = mass ÷  volume = 350 g ÷ 100 cm³ = 3.5g/cm³

Question 8:

A tank filled with water has a volume of 0.02 m³

(a) 1 liter = 0.001 m³

How many liters? = 0.02 m³ ?

Cross multiplying gives:

[tex]\frac{0.02 * 1}{0.001}[/tex] =  20 liters

(b) 1 m³ = 1,000,000 cm³

0.02 m³ = how many cm³ ?

Cross-multiplying gives;

[tex]\frac{0.02 * 1,000,000}{1}[/tex] = 20,000 cm³

(c) 1 cm³ = 1 ml

∴ 0.02 m³ of the water = 20,000 cm³ = 20,000 ml

Question 9:

Caliper (a) measurement = 3.2 cm

Caliper (b) measurement = 3 cm

Question 10:

The mass of the liquid which overflow = mass of the stone = 20 g

1 gram of the liquid occupies 1 cm³ of space.

20 g of the liquid will occupy; [tex]\frac{20 * 1}{1}[/tex] = 20 cm³

(a) Since the volume of the water displaced is equal to the volume of the stone.

∴ The volume of the stone = 20 cm³

(b) Mass = density ×  volume

Density of the stone = 5.0 g/cm³

Volume of the stone = 20 cm³

Mass of the stone = 5 g/cm³ × 20 cm³ = 100 g

Answer:

Nitrogen gas (N2) is a molecule because the bond between the nitrogen atoms is a molecular bond. Water (H2O) is a molecular compound because it is a substance made from more than one kind of element that is held together with molecular bonds

Explanation:

Answer:

Similarities:

Energy can be transferred from one form to another in both systems.

Difference:

Energy can only be created or destroyed in conservation of energy.

Explanation:

Conservation of energy: tell us that energy can neither be created nor destroyed, but can be transferred from one form to another. e.g Chemical to mechanical ( combustion of fuel in vehicle to achieve mechanical work. )

Energy transfer Conservation

Energy can be stored or transferred from one form to another, but it cannot be created or destroyed.

Similarities:

Energy can be transferred from one form to another in both systems.

Difference:

Energy can only be created or destroyed in conservation of energy.

Answer:

Explanation:

bv

Answer:

B. the object will begin to move

Explanation:

If energy is transferred the object will definitely change so it CANNOT be "A". If you add energy the object will have more force so it CANNOT be "C". The mass of an object can't increase just by giving an object energy so it CANNOT be "D"

Given parameters:

Mass of each tablet  = 250mg   = 0.25g

Mass of all tablets in the bottle = 1kg  = 1000g

Unknown:

Number tablets in the bottle = ?

Solution:

The number of tablets in the bottle;

    Number of tablets  = [tex]\frac{mass of all tablets in the bottle}{mass of each tablet}[/tex]

                     Mass is the amount of matter that makes up a substance

Number of tablets  = [tex]\frac{1000g}{ 250 x 10^{-3} }[/tex]   = 4000 tablets

Considering the rule of three, the number of tablets in the bottle is 4.

In first place, the rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.

That is, what is intended with it is to find the fourth term of a proportion knowing the other three.  

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied.

To solve a direct rule of three, the following formula must be followed, being a, b and c known data and x the variable to be calculated:

a ⇒ b

c ⇒ x

So: [tex]x=\frac{cxb}{a}[/tex]

The direct rule of three is the rule applied in this case as follow:  if 250 mg = 0.250 g is the mass of 1 medicinal tablet, 1 kg = 1000 g is the mass of how many medicinal tablets?

0.250 grams ⇒ 1 medicinal tablet

1000 grams ⇒ x

Then:

[tex]x=\frac{1000 gramsx1 medicinal tablet}{0.250 grams}[/tex]

x= 4 medicinal tablets

Finally, the number of tablets in the bottle is 4.

Learn more:

Answer:  Initial Velocity = 2.8 km/h

Final Velocity = 32 km/h

Explanation:

Answer:

magma

Explanation:

actually cooling and solidification of magma

I think it would be, D. Warm air in a hot air balloon rises and heats air at the top of the  balloon.

The scenario that represents an example of the transfer of thermal energy by convection is the warm air in a hot air balloon rises and heats air at the top of the balloon. Thus, the correct option for this question is D.

Convection may be defined as a type of process through which heat is significantly transferred by the movement of a heated fluid such as air or water. It involves the transfer of heat by the movement of a fluid (liquid or gas) between areas of different temperatures.

Thermal energy refers to the energy which is contained within a system that is responsible for its temperature. Heat is the flow of thermal energy.

This thermal energy gets transferred through the process of convection from the top of the balloon in an example of a hot air balloon. The concept of this works on the warm air that is filled in a balloon and this warm air rises and heats air at the top of the balloon.

Therefore, the correct option for this question is D.

To learn more about Convection, refer to the link:

https://brainly.com/question/9382711

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Answer:

grav times mass equals force

Explanation:

Heat moves in three ways: Radiation, conduction, and convection. Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else. This is how the heat from the Sun gets to Earth. In fact, all hot things radiate heat to cooler things.