Why should scietist as questions

Find the average speed of a person who swims 105 m in 70 s

spin [16.1K]

Answer:

v = 1.5 m/s

Explanation:

Given that,

Distance covered by a person, d = 105 m

Time taken, t = 70 s

We need to find the average speed of the person. We know that the average speed is given by :

$v=\dfrac{d}{t}\\\\v=\dfrac{105\ m}{70\ s}\\\\v=1.5\ m/s$

So, the average speed of the person is equal to 1.5 m/s.

4 0

2 years ago

BALANCE the equation

Anna11 [10]

Answer:

1. 4FeCl3 + 3O2 → 2Fe2O3 + 6Cl2

2. 6 moles of Cl2

Explanation:

1. The balanced equation for the reaction. This is illustrated below:

4FeCl3 + 3O2 → 2Fe2O3 + 6Cl2

2. Determination of the number of mole of Cl2 produce when 4 moles of FeCl3 react with 4 moles. To obtain the number of mole of Cl2 produced, we must determine which reactant is the limiting reactant.

This is illustrated below:

From the balanced equation above,

4 moles of FeCl3 reacted with 3 moles of O2.

Since lesser amount of O2 (i.e 3 moles) than what was given (i.e 4 moles) is needed to react completely with 4 moles of FeCl3, therefore FeCl3 is the limiting reactant and O2 is the excess reactant.

Finally, we can obtain the number of mole Cl2 produced from the reaction as follow:

Note: the limiting reactant is used as it will produce the maximum yield of the reaction since all of it is used up in the reaction.

From the balanced equation above,

4 moles of FeCl3 will react to produced 6 moles of Cl2.

8 0

3 years ago

A jar is filled with water, and the lid is closed tightly. The jar is kept at constant temperature. What happens at the surface

Katarina [22]

<h2>Hello!</h2>

The correct answer is A: Water molecules evaporate and condense at the same rate.

Evaporation is defined as the physical change from liquid to gas, and Condensation is the physical change from gas to liquid.

At any given temperature, these two processes occur at once, in a dynamic equilibrium.

When the lid is closed, evaporation occurs faster than condensation, and pressure increases. Then, when pressure reaches a critical value, condensation starts to occur faster than evaporation, until an equilibrium is reached, and the pressure of the water molecules in the gas phase is maximum for that temperature. The pressure at that point is called Vapor Pressure.

Have a nice day!

5 0

2 years ago

If 5.0 kJ of energy is added to a 15.5-g sample of water at 10.°C, the water is Group of answer choices

BaLLatris [955]

Answer:

The water is completely vaporized at this stage.

Explanation:

The complete question is

If 5.0 kJ of energy is added to a 15.5-g sample of water at 10.°C, the water is

-boiling

-completely vaporized

-frozen solid

-decomposed

-still a liquid

Energy added = 50 kJ = 50000 J

mass of water = 15.5 g = 0.0155 kg

temperature of water = 10 °C

We know that the energy posses by a mass of water at a given temperature is given as

H = mcT

where H is the energy possessed by the mass of water

m is the mass of the water

c is the specific heat capacity of water = 4200 J/ kg- °C

T is the temperature of the water

substituting values, the energy of this amount of water is

H = 0.0155 x 4200 x 10 = 651 J

If 50 kJ is added to the water, the energy increases to

50000 J + 651 J = 50651 J

Temperature of this water at this stage will be gotten from

H = mcT

we solve for the new temperature

50651 = 0.0155 x 4200 x T

50651 = 65.1 x T

T = 50651/65.1 = 778.05 °C

This temperature is well over 100 °C, which is the vaporization temperature of water, but less than 3000 °C for its molecules to decompose.

3 0

3 years ago

The maximum number of trees that can be grown in an area and have all of the resources they need to survive is the forest's ____

alisha [4.7K]

Answer:

growth limit for trees

Explanation:

the awnser is the growth limit for trees

6 0

2 years ago

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