The answer is commensalism because commensalism is a relationship where an organism is benefitted and the other is neither benefitted nor harmed. The barnacle is being benefited and the whale is not being benefited or harmed.
Answer:
20.6 m
Explanation:
P₁ = Power of first bulb = 45 W
P₂ = Power of second bulb = 130 W
r₁ = distance from the first bulb
r₂ = distance from the second bulb = 35 m
Using the equation
Inserting the values
r₁ = 20.6 m
I assume the 100 N force is a pulling force directed up the incline.
The net forces on the block acting parallel and perpendicular to the incline are
∑ F[para] = 100 N - F[friction] = 0
∑ F[perp] = F[normal] - mg cos(30°) = 0
The friction in this case is the maximum static friction - the block is held at rest by static friction, and a minimum 100 N force is required to get the block to start sliding up the incline.
Then
F[friction] = 100 N
F[normal] = mg cos(30°) = (10 kg) (9.8 m/s²) cos(30°) ≈ 84.9 N
If µ is the coefficient of static friction, then
F[friction] = µ F[normal]
⇒ µ = (100 N) / (84.9 N) ≈ 1.2