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3 years ago

A cheetah has been clocked at 112 km/h over a 100-m distance. What is this speed in m/s?

Chemistry

1 answer:

Serhud [2]3 years ago

8 0

M/sec = 112 km / 1 hr / 1 min / 1000 meters
hr / 60 min / 60 sec / 1 km

So the answer is = 31.1 meters/sec

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After the discovery of the microscope, many microorganisms were placed into taxonomic categories. What characteristic of science

Mrac [35]

It changes with new evidence.

The example shows that science changes with new evidence. Science can not change with common beliefs because first of all beliefs should be proved and become evidence. Second, science is not fixed because of the scientific method and experimentation, which is a phase of the scientific method.

5 0

4 years ago

Read 2 more answers

You have a hard glass flask that you plug up with a stopper at room temperature (25 C) and an internal pressure of 1 atm. If you

liubo4ka [24]

Answer:

pressure of 0atm

Explanation:

5 0

3 years ago

A copper atom has a mass of 1 06 times 10^-22 g and a penny has a mass of 2.5 g. Use this information to answer the questions be

amm1812

Answer:

Mass of 1 mole of copper is 63.83 g.

0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.

Explanation:

Mass of 1 copper atom,m = $1.06\times 10^{-22} g$

$1 mole = 6.022\times 10^{23} atoms$

Mass of 1 mole of copper :

= $6.022\times 10^{23} atoms\times 1.06\times 10^{-22} g=63.83 g$

Mass of 1 mole of copper = 63.83 g

Mass of copper penny = 2.5 g

Atomic mass of copper = 63.83 g/mol

Moles of copper in 2.5 g of copper penny:

$\frac{2.5 g}{63.83 g/mol}=0.03916 mol$

0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.

8 0

3 years ago

Calculate the amount of heat that must be absorbed by 10.0 g of ice at –20°C to convert it to liquid water at 60.0°C. Given: spe

Murljashka [212]

Answer:

The amount of heat to absorb is 6,261 J

Explanation:

Calorimetry is in charge of measuring the amount of heat generated or lost in certain physical or chemical processes.

The total energy required is the sum of the energy to heat the ice from -20 ° C to ice of 0 ° C, melting the ice of 0 ° C in 0 ° C water and finally heating the water to 60 ° C.

So:

Heat required to raise the temperature of ice from -20 °C to 0 °C

Being the sensible heat of a body the amount of heat received or transferred by a body when it undergoes a temperature variation (Δt) without there being a change of physical state (solid, liquid or gaseous), the expression is used:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation (ΔT=Tfinal - Tinitial).

In this case, m= 10 g, specific heat of the ice= 2.1 $\frac{J}{g*C}$ and ΔT=0 C - (-20 C)= 20 C

Replacing: Q= 10 g*2.1 $\frac{J}{g*C}$ *20 C and solving: Q=420 J

Heat required to convert 0 °C ice to 0 °C water

The heat Q necessary to melt a substance depends on its mass m and on the called latent heat of fusion of each substance:

Q= m* ΔHfusion

In this case, being 1 mol of water= 18 grams: Q= 10 g* $6.0 \frac{kJ}{mol} *\frac{1 mol of water}{18 g}$ = 3.333 kJ= 3,333 J (being kJ=1,000 J)

Heat required to raise the temperature of water from 0 °C to 60 °C

In this case the expression used in the first step is used, but being: m= 10 g, specific heat of the water= 4.18 $\frac{J}{g*C}$ and ΔT=60 C - (0 C)= 60 C

Replacing: Q= 10 g*4.18 $\frac{J}{g*C}$ *60 C and solving: Q=2,508 J

Finally, Qtotal= 420 J + 3,333 J + 2,508 J

Qtotal= 6,261 J

The amount of heat to absorb is 6,261 J

3 0

3 years ago

Which of the following correctly describes the law of conservation of energy

egoroff_w [7]

Mass and energy can not be created or destroyed, they may be able to just be converted, and neither one seems without the opposite. For this reason in closed systems, both mass and energy are conserved individually. " I hope this helps "

3 0

3 years ago