(a) 
The relationship beween centripetal acceleration and angular speed is

where
is the angular speed
r is the radius of the circular path
Here we gave
is the centripetal acceleration
r = 5.15 m is the radius
Solving for
, we find:

(b) 21.3 m/s
The relationship between the linear speed and the angular speed is

where
v is the linear speed
is the angular speed
r is the radius of the circular path
In this problem we have

r = 5.15 m
Solving the equation for v, we find

Well if it was traveling for an hour then the answer is 8 miles.
Answer:
0.25 gram of neptunium is remaining
Explanation:
First we calculate the no. of half lives passed. For that we have formula:
n = t/T
where,
n = no. of half lives passed = ?
t = total time passed = 8 days (From Monday noon to Tuesday noon of following week)
T = Half Life Period = 2 days
Therefore,
n = 8 days/2 days
n = 4
Now, for the remaining mass of neptunium, we use the formula:
m = (mi)/(2)^n
where,
mi = initial mass of neptunium = 4.00 grams
m = remaining mass of neptunium = ?
Therefore,
m = 4 grams/2⁴
<u>m = 0.25 gram</u>