Answer: a dark (absorption) line
Explanation:
This is as a result of absorption of electromagnetic a specific wavelength. The pattern followed by such lines is characteristic of specific atoms in the path of radiation.
Answer:
5.09 m/s
Explanation:
Use the height to find the time it takes to land:
y = y₀ + v₀ᵧ t + ½ gt²
0 = 8.0 m + (0 m/s) t + ½ (-9.8 m/s²) t²
t = 1.28 s
Now use the horizontal distance to find the initial velocity.
x = x₀ + v₀ₓ t + ½ at²
6.5 m = 0 m + v₀ (1.28 s) + ½ (0 m/s²) (1.28 s)²
v₀ = 5.09 m/s
Input heat, Qin = 4 x 10⁵ J
Output heat, Qout = 3.5 x 10⁵ J
From the first Law of thermodynamics, obtain useful work performed as
W = Qin - Qout
= 0.5 x 10⁵ J
By definition, the efficiency is
η = W/Qin
= 100*(0.5 x 10⁵/4 x 10⁵)
= 12.5%
Answer: The efficiency is 12.5%
