The correct answer as the first one above !
Answer:
D
Explanation:
- The rate of the Diels-Alder is orders of magnitude faster if there is an electron-withdrawing group on the dienophile. For example, replacing a hydrogen on ethene with the electron-withdrawing group CN results in about a 10^5 increase in the reaction rate.
- Other common electron withdrawing functional groups that will accelerate the Diels Alder reaction of dienophiles include aldehydes, ketones, and esters.
- In short, any functional group conjugated with the pi bond which can act as a pi acceptor will accelerate a Diels-Alder reaction with a typical diene.
- See attachment for graphical explanation.
m = mass = 1,200 kg
A = acceleration = 3 m/s^2
Apply Newton's second law:
Force = mass x acceleration
F = 1,200 x 3 =3600 N
The net force the car experiences is 3600 N
Answer:
Photons strike the CD 
Explanation:
First of all, it is necessary to calculate the energy produced by a semiconductor laser for 69 minutes:


Next, it is possible to calculate the number of photons striking the CD surface during this time:

long in CD
light velocity
Solve to n'

