Answer:
1. A
sound can't travel through vacuum only
Explanation:
The rod is uniform, so the center of gravity is at the center, or 0.75 m from the end. The wedge is 0.5 m from the end, so the center is 0.25 m from the wedge.
Sum the torques about the wedge (it may help to draw a diagram first). Take counterclockwise to be positive.
∑τ = Iα
W (0.25 m) − (100 N) (0.50 m) = 0
W = 200 N
Sum the forces in the y direction.
∑F = ma
F − 100 N − 200 N = 0
F = 300 N
Answer:
0.043 m
Explanation:
From the attachment, the shaded part is the ethyl alcohol. The crossed part on the other hand, is that of glycerin.
The height of the Ethyl Alcohol is h2 = 0.25 m, it's density is ρ2 = 790 kg/m³. The density of glycerin is ρ1 = 1260 kg/m³
If we assume pressure at the two points to be the same, then
P1 = P2
ρ1.g.V1 = ρ2.g.V2
ρ1.A.h1 = ρ2.A.h2
ρ1.h1 = ρ2.h2, making h1 subject of formula
h1 = ρ2.h2 / ρ1, so that
h1 = 790 * 0.25 / 1260
h1 = 197.5 / 1260
h1 = 0.157 m
Δh = 0.2 - 0.157
Δh = 0.043 m or 4.3 cm
Answer:
Efficiency = 77%
Explanation:
Input energy = 570 J
Output energy = 440 J
To find the efficiency;
Substituting into the equation, we have;

Efficiency = 77.19 ≈ 77%
Therefore, the efficiency of the engine is 77 percent.