Answer:
The second option
Explanation:
Speed is defined at the rate at which distance changes with time. It is scalar quantity and it is expressed as shown below:
Speed = 
At constant speed the rate of change of distance with time is the same. On the second graph, this is noticeable. Both distance and time change at the same rate.
Check the attached file for the answer.
Answer:
East
Explanation:
Given Newton's third law of motion; "Action and reaction are equal and opposite", when a student jumps off a sled toward the west after it stops at the bottom of an icy hill, the sled will move in the East direction.
This is because, the force exerted on the sled is a reaction force and is opposite in direction to the force that thrusts the boy westward though equal in magnitude with the former.
Answer: The activation energy Ea for this reaction is 22689.8 J/mol
Explanation:
According to Arrhenius equation with change in temperature, the formula is as follows.
![ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}]](https://tex.z-dn.net/?f=ln%20%5Cfrac%7Bk_%7B2%7D%7D%7Bk_%7B1%7D%7D%20%3D%20%5Cfrac%7B-E_%7Ba%7D%7D%7BR%7D%5B%5Cfrac%7B1%7D%7BT_%7B2%7D%7D%20-%20%5Cfrac%7B1%7D%7BT_%7B1%7D%7D%5D)
= rate constant at temperature 
= 
= rate constant at temperature 
= 
= activation energy = ?
R= gas constant = 8.314 J/kmol
= temperature = 
= temperature = 
Putting in the values ::
![ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}]](https://tex.z-dn.net/?f=ln%20%5Cfrac%7B4.8%5Ctimes%2010%5E8%7D%7B2.3%5Ctimes%2010%5E8%7D%20%3D%20%5Cfrac%7B-E_%7Ba%7D%7D%7B8.314%7D%5B%5Cfrac%7B1%7D%7B649%7D%20-%20%5Cfrac%7B1%7D%7B553%7D%5D)
The activation energy Ea for this reaction is 22689.8 J/mol
Four molecules have carbon as the central atom and hydrogen atoms around it. The shape that would give rise to a polar molecule is a bent shape. <span>The bent shape will not be symmetrical which will result to being polar. Hope this answers the question.</span>
