James stewart, 2002 motorcross/supercross rookie of the year, is leading a race when he runs out of gas near the finish line. he is moving at 16 m/s when he enters a section of the course covered with sand where the effective coefficient of friction is 0.90. will he be able to coast through this 15-m-long section to the finish line at the end? if yes, what is his speed at the finish line?

We are given the coefficient of friction which is:
Cf = 0.90
The acceleration based on this would be:
a = -Cf * g 
a = -0.90 * (9.81 m/s^2)
a = -8.83 m/s^2
Calculate the distance at his total stop v = 0 using the formula:
v^2 = vo^2 + 2ad
where v is final velocity = 0, vo is initial velocity = 16, d is distance
0 = 16^2 + 2 (-8.83) d
d = 14.5 m
So he is short by 0.5 m, he does not reach the finish line

What does the start look like

Answerthe valence of an element or radical is equal to the number of positive or negative charges on the ion.