Step-by-step explanation:
The upstream speed is S / t₁, and the downstream speed is S / t₂.
If we say f is the speed of the fish in calm water, and r is the speed of the river, then:
f − r = S / t₁
f + r = S / t₂
If we say T is the time it takes to cross the river, then the speed perpendicular to the river is ℓ/T, the speed parallel to the river is r, and the overall speed is f.
Using Pythagorean theorem:
f² = (ℓ/T)² + r²
f² − r² = (ℓ/T)²
(f − r) (f + r) = (ℓ/T)²
(S / t₁) (S / t₂) = (ℓ/T)²
S² / (t₁ t₂) = (ℓ/T)²
(t₁ t₂) / S² = (T/ℓ)²
√(t₁ t₂) / S = T/ℓ
T = ℓ√(t₁ t₂) / S
Answers are A, D
Because they will have people that don’t like sports and do like sports where as if you survey them in a sports shop there gonna like sports otherwise they wouldn’t be there
Perpendicular lines<span> are two or more lines that intersect at a 90-degree angle, like the two lines drawn on this graph, and the x and y axes that orient them.</span>
<span> </span>
Answer:
15
Step-by-step explanation:
Sorry I'm in high school.. but according to my physics class, the instantaneous speed is when t (time) is 0, or whatever you'd use (like x).. anyways, when t=0, the instantaneous speed would be 3 ft/s, and the instantaneous acceleration is 0.
