Step-by-step explanation:
Given:
This field will have a scalar potential 
if it satisfies the condition 
. While the first x- and y- components of 
are satisfied, the z-component doesn't.
Therefore the field is nonconservative so it has no scalar potential. We can still calculate the work done by defining the position vector 
as
and its differential is
The work done then is given by
Answer:
y is 10 degrees the pink one
The question also states that Lucy has a winning probability of 1/50, which means that she has 1 chance of winning if the total runners were 50. Therefore, there are 49 runners who may be faster than her.
The fact that Lucy is the 50th slowest runner, means that starting from the slowest she is in 50th position, therefore there are 49 runners that are slower than her.
The total number of runners will be the sum of those faster than Lucy, those slower than Lucy and Lucy:
49 + 49 + 1 = 99
There are 99 runners in Lucy's school.
