Answer:
Thx a lot
Step-by-step explanation:
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
Answer:
(b) 1:9
(c) 1:8
Step-by-step explanation:
(b) x*y : kx*ky, so 1:k² with k=3 is 1:9
(c) Assuming the rectangles get a z dimension, the volumes would have a ratio of xyz : xkykzk = xyz : xyzk³ = 1 : k³. With k=2 that is 1:8. But the z was never introduced so this is a bit inconclusive.
Answer:
Step-by-step explanation:
Poste uma foto do problema plss