The first, third, fourth, fifth and sixth
Given data:
Yan speed;

Christopher speed;

Christophe starts 30 s later than Yan. Therefore, Christophe takes 30 s less than Yan to reach the same distance.
Part (A)
The distance is given as,

Let both Yan and Christophe meet at d distance from the start position. Therefore,

Substituting all known values,

Therefore, 600 s after Yan's departure Christophe will join him.
Part (B)
The distance is given as,

Substituting all known values,

Therefore, Christophe joins Yan after 6.17 km from the start.
120 minutes=2 hours
20/2= 10mph
the correct answer is no ;)
Answer:

Explanation:
The electric field inside a parallel plate capacitor is

where A is the area of one of the plates, and Q is the charge on the capacitor.
The electric force on the electron is

where q is the charge of the electron.
By definition the capacitance of the capacitor is given by

Plugging this identity into the force equation above gives

The work done by this force is equal to change in kinetic energy.
W = Fx = (30q)(0.05) = 1.5q = K
The charge of the electron is 
Therefore, the kinetic energy is 