Answer:
Electric field, 
Explanation:
It is given that,
Charge, Q = +6.1 C
Distance, r = 21 cm = 0.21 m
We need to find the electric field. It is given by :



So, the electric field at this distance is
. Hence, this is the required solution.
For Plato, the correct answer is Concave mirror :)
Answer: 4.8 s
Explanation:
We have the following data:
the mass of the raft
the force applied by Sawyer
the raft's final speed
the raft's initial speed (assuming it starts from rest)
We have to find the time 
Well, according to Newton's second law of motion we have:
(1)
Where
is the acceleration, which can be expressed as:
(2)
Substituting (2) in (1):
(3)
Where 
Isolating
from (3):
(4)
Finally:
Answer:
The distance traveled!
Explanation:
This is a velocity time graph of an object moving in a straight line due North.