Answer:
1) 9.8×10⁻⁹ m/s
2) 50970.3238656 L
Explanation:
1) In 30 days hair grows 1 inch
1 inch = 2.54 cm
1 cm = 0.01 m
2.54 cm = 2.54 × 0.01 m
⇒2.54 cm = 0.0254 m
30 days = 30×24×60×60 = 2592000 seconds
Speed = Distance / Time
Speed at which hair grows is 9.8×10⁻⁹ m/s
2) 1 ft = 0.3048 m
0.3048 m = 30.48 cm
1 ft = 30.48 cm
15 ft = 15×30.48 = 457.2 cm
8 ft = 8×30.48 = 243.84 cm
Volume of water in pool = Length × Width × Depth
⇒Volume of water in pool = 457.2×457.2×243.84
⇒Volume of water in pool = 50970323.8656 cm³
or
Volume of water in pool = 15×15×8 = 1800 ft³
1 ft³ = 30.48³ cm³
1800 ft³ = 30.48³ × 1800 = 50970323.8656 cm³
Converting to liters
1 L = 1000 cm³
0.001 L = 1 cm³
50970323.8656 cm³ = 50970323.8656×0.001 = 50970.3238656 L
Volume of water in pool is 50970.3238656 L
The FFA is the Future Farmers of America. It has no authority in aeronautical matters.
On the list of choices that you provided, there is no such statement.
Answer:
a) t₁ = 4.76 s, t₂ = 85.2 s
b) v = 209 ft/s
Explanation:
Constant acceleration equations:
x = x₀ + v₀ t + ½ at²
v = at + v₀
where x is final position,
x₀ is initial position,
v₀ is initial velocity,
a is acceleration,
and t is time.
When the engine is on and the sled is accelerating:
x₀ = 0 ft
v₀ = 0 ft/s
a = 44 ft/s²
t = t₁
So:
x = 22 t₁²
v = 44 t₁
When the engine is off and the sled is coasting:
x = 18350 ft
x₀ = 22 t₁²
v₀ = 44 t₁
a = 0 ft/s²
t = t₂
So:
18350 = 22 t₁² + (44 t₁) t₂
Given that t₁ + t₂ = 90:
18350 = 22 t₁² + (44 t₁) (90 − t₁)
Now we can solve for t₁:
18350 = 22 t₁² + 3960 t₁ − 44 t₁²
18350 = 3960 t₁ − 22 t₁²
9175 = 1980 t₁ − 11 t₁²
11 t₁² − 1980 t₁ + 9175 = 0
Using quadratic formula:
t₁ = [ 1980 ± √(1980² - 4(11)(9175)) ] / 22
t₁ = 4.76, 175
Since t₁ can't be greater than 90, t₁ = 4.76 s.
Therefore, t₂ = 85.2 s.
And v = 44 t₁ = 209 ft/s.
