2. what is nappening in this diagram:

A bike rider approaches a hill with a speed of 8.5 m/s. The total mass of the bike and the rider is 85 kg. Find the kinetic ener

krek1111 [17]

KE=3070.625 J

Height = 3.686 m

<h3>Further explanation</h3>

mass of bike+rider=85 kg

velocity = 8.5 m/s

$\tt KE=\dfrac{1}{2}mv^2\\\\KE=\dfrac{1}{2}\times 85\times 8.5^2\\\\KE=3070.625~J$

Conservation of energy :

(KE+PE)₁ (downhill) = (KE+PE)₂ (up the hill)

PE₁=0⇒h=0

KE₂=0⇒v=0(stop), so equation becomes :

KE₁=PE₂

$\tt KE_1=3070.625\\\\KE_1=mgh_2\\\\3070.625=85\times 9.8\times h\Rightarrow h=3.686~m$

5 0

2 years ago

Combine the two half-reactions that give the spontaneous cell reaction with the smallest E∘. Fe2+(aq)+2e−→Fe(s) E∘=−0.45V I2(s)+

Iteru [2.4K]

Answer: The spontaneous cell reaction having smallest $E^o$ is $I_2+Cu\rightarrow Cu^{2+}+2I^-$

Explanation:

We are given:

$E^o_{(Fe^{2+}/Fe)}=-0.45V\\E^o_{(I_2/I^-)}=0.54V\\E^o_{(Cu^{2+}/Cu)}=0.34V$

The substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction. Here, iodine will always undergo reduction reaction, then copper and then iron.

The equation used to calculate electrode potential of the cell is:

$E^o_{cell}=E^o_{oxidation}+E^o_{reduction}$

The combination of the cell reactions follows:

Case 1:

Here, iodine is getting reduced and iron is getting oxidized.

The cell equation follows:

$I_2(s)+Fe(s)\rightarrow Fe^{2+}(aq.)+2I^-(aq.)$

Oxidation half reaction: $Fe(s)\rightarrow Fe^{2+}(aq.)+2e^-$ $E^o_{oxidation}=0.45V$

Reduction half reaction: $I_2(s)+2e^-\rightarrow 2I_-(aq.)$ $E^o_{reduction}=0.54V$

$E^o_{cell}=0.45+0.54=0.99V$

Thus, this cell will not give the spontaneous cell reaction with smallest $E^o_{cell}$

Case 2:

Here, iodine is getting reduced and copper is getting oxidized.

The cell equation follows:

$I_2(s)+Cu(s)\rightarrow Cu^{2+}(aq.)+2I^-(aq.)$

Oxidation half reaction: $Cu(s)\rightarrow Cu^{2+}(aq.)+2e^-$ $E^o_{oxidation}=-0.34V$

Reduction half reaction: $I_2(s)+2e^-\rightarrow 2I_-(aq.)$ $E^o_{reduction}=0.54V$

$E^o_{cell}=-0.34+0.54=0.20V$

Thus, this cell will give the spontaneous cell reaction with smallest $E^o_{cell}$

Case 3:

Here, copper is getting reduced and iron is getting oxidized.

The cell equation follows:

$Cu^{2+}(aq.)+Fe(s)\rightarrow Fe^{2+}(aq.)+Cu(s)$

Oxidation half reaction: $Fe(s)\rightarrow Fe^{2+}(aq.)+2e^-$ $E^o_{oxidation}=0.45V$

Reduction half reaction: $Cu^{2+}(aq.)+2e^-\rightarrow Cu(s)$ $E^o_{reduction}=0.34V$

$E^o_{cell}=0.45+0.34=0.79V$

Thus, this cell will not give the spontaneous cell reaction with smallest $E^o_{cell}$

Hence, the spontaneous cell reaction having smallest $E^o$ is $I_2+Cu\rightarrow Cu^{2+}+2I^-$

7 0

2 years ago

Will give brainliest

mote1985 [20]

Answer:

1)Around 450 B.C., the Greek philosopher Democritus introduced the idea of the atom.

2)All matter is made of atoms, Atoms are indivisible and indestructible.Compounds are formed by a combination of two or more different kinds of atoms, A chemical reaction is a rearrangement of atoms.

3)B

Explanation:

7 0

2 years ago

Alka-seltzer is an antacid that is dissolved in water before use. for an experiment, three tablets of alka-seltzer are dissolved

Naddika [18.5K]

Alka-seltzer in an antacid that contains a mixture of sodium bicarbonate and citric acid. When the tablet is dissolved in water, the reactants which are in solid form in tablet become aqueous and react with each other.

During this reaction, Carbon Dioxide gas is evolved which causes the reaction mixture to fizz. The equation is given below.

$NaHCO_{3}\ (aq) + H_{3}C_{6}H_{5}O_{7} (aq)\rightarrow Na_{3}C_{6}H_{5}O_{7}(aq)+ CO_{2}(g)+H_{2}O (l)$

Rate of the above reaction is affected by the Temperature.

As the temperature increases , the rate of the reaction increases. This happens because at higher temperature, the collisions between reacting species are more which result in formation of product in less time. This increases the rate of reaction.

We have been given equal volumes of water for each beaker. But the temperature of beaker c is 80°C which is the highest temperature. That means the reaction in beaker c is fastest.

Whereas beaker a is at lowest temperature (30°C) , therefore the reaction in beaker a would be slowest .

Therefore the answer that correctly orders the reaction rates from fastest to slowest reaction is beaker c > beaker b > beaker a

8 0

3 years ago

Disposal site for solid waste

Alexxandr [17]

Answer:

"where deliberately discarded solid waste is discharged, deposited, injected, dumped, spilled, leaked, or placed so that such solid waste or a constituent thereof may enter the environment or be emitted into the air or discharged into waters, including ground waters."

Explanation:

https://definitions.uslegal.com/s/solid-waste-disposal-site/

7 0

2 years ago