D. distance = 23 m, displacement = + 1 m
Explanation:
Let's remind the difference between distance and displacement:
- distance is a scalar, and is the total length covered by an object, counting all the movements in any direction
- displacement is a vector connecting the starting point and the final point of a motion, so its magnitude is given by the length of this vector, and its direction is given by the direction of this vector.
In this case, the distance covered by Karen is given by the sum of all its movements:

The displacement instead is given by the difference between the final point (1.0 m in front of the starting line) and the starting point (the starting line, 0 m):

Answer:
These energy exchanges are not changes in kinetic energy. They are changes in bonding energy between the molecules. If heat is coming into a substance during a phase change, then this energy is used to break the bonds between the molecules of the substance.
Answer:
a) 1111.0 seconds
b) 833.3 s
c) Because of proportions
Explanation:
a) Total time of round trip is the sum of time upriver and time downriver

Time upriver is calculated with the net speed of student and 0.500 km:

(Becareful with units 0.5 km= 500m) Similarly of downriver:

So the sum is:

b) Still water does not affect student speed, so total time would be simply:

c) For the upriver trip, student moved half the distance in half speed of the calculation in b), so it kept the same ratio and therefore, same time. So the aditional time is actually the downriver.