Answer:
r = - 
Step-by-step explanation:
Given that r varies inversely as t , then the equation relating them is
r = 
← k is the constant of variation
To find k use the condition t = - 6 when r = - 2, then
- 2 = 
( multiply both sides by - 6 )
12 = k, thus
r = 
← equation of variation
when t = - 7, then
r = 
= -
I would have to go with B as your answer
Answer:
640
Step-by-step explanation:
Answer:
t₁ = 2,75 sec
Step-by-step explanation:
The ball will get h maximum when dh/dt ( its vertical component of the speed is equal to 0. At this moment the ball has flown half of the total flight time
Then
h(t) = - 4t * ( 4*t - 11 )
h(t) = - 16*t² + 44*t
Taking derivatives on both sides of the equation we get:
dh/dt = - 32*t + 44
dh/dt = 0 ⇒ -32*t + 44 = 0
t = 44/32 ⇒ t = 1,375 s
So twice this time
2*t = 2 * 1.375
Total time t₁ = 2,75 sec
