Looks like you need to review through the lesson and take notes as it tells you in the lesson what each of these are.
Answers:
kinetic energy lost = 86.4J
Explanation:
let Kf be the kinetic energy after the collision and Ki be the kinetic energy before the collision. let the 3kg car be 1 and 2kg car be 2.
Kf = K1(f) + K2(f)
Ki = K1(i) + k2(i)
loss in kinetic energy = Kf - Ki
= 1/2(3)(2.20)^2 + 1/2(2)(2.20)^2 - 1/2(3)(7)^2 - 1/2(2)(-5)^2
= 12.1 - 98.5
= -86.4 J
therefore, the kinetic energy lost in the collision is 86.4 J.
Answer:
The change in potential energy is 
Explanation:
From the question we are told that
The magnitude of the uniform electric field is 
The distance traveled by the electron is 
Generally the force on this electron is mathematically represented as
Where F is the force and q is the charge on the electron which is a constant value of 
Thus


Generally the work energy theorem can be mathematically represented as

Where W is the workdone on the electron by the Electric field and
is the change in kinetic energy
Also workdone on the electron can also be represented as
Where
considering that the movement of the electron is along the x-axis
So

substituting values


Now From the law of energy conservation
Where
is the change in potential energy
Thus

The answer is B because it literally says it right there, and I don't wanna make it impossibly confusing for a middle school student, lol.
Because Charles Darwin went and researched the animals on the Galapagos islands.