Answer:
Her centripetal acceleration during the turn at each end of the track is 
Step-by-step explanation:
Total distance covered in one round , D= 400 m
Time taken to cover one round , T = 1 min 40 s = 100 sec
Speed of runner , 
Now centripetal acceleration is given by

where 


Thus her centripetal acceleration during the turn at each end of the track is 
Suppose the larger pump alone can empty the tank in L hours, and the smaller pump can finish the job in S hours, then each hour the large pump empties 1/L portion of the tank, and the small pump empties 1/S per hour
Working together for three hours, they empty the whole tank, which is 100% of it, so 3/L+3/S=100%=1
Larger pump can empty the tank in 4 hours less than the smaller one, so L=S-4
replace L: 3/(S-4)+3/S=1
Make the denominator the same to solve for:
3S/[S(S-4)] +3(S-4)/[S(S-4)]=1
(3S+3S-12)/[S(S-4)]=1
(3S+3S-12)=[S(S-4)]
S^2-10s+12=0
use the quadratic formula to solve for S
S is about 8.6
The answer is not whole hour.
This system of equations is consistent and independent, because there is only one solution. the answer is C
Answer:
8.1
Step-by-step explanation:
2x^2 -9 = 121
+9 +9
2x^2 = 130
/2 /2
x^2 = 65
x= sqrt (65)
x= 8.06225...
x = 8.1
Answer:
x =20
Step-by-step explanation:
As a line is 180 degrees
So 7x + 40 would be 180, which would lead us with the equation:
7x+40=180
=7x =140 (minus both sides by 40)
=x =20 (divide both sides by 7)