Answer:

Explanation:
From the question, using the expression:

where;



This is a combined intensity of 4 speakers.
Thus, the intensity of 3 speakers = 
= 2.372 W/m²
Thus;


90+66=156
156/2=78
Reply:78kilometers in 2 hours.
Answer: The softer barrier is the better option
Explanation:
1) When is a car is moving at a certain speed, it has a certain amount of momentum (p=mv). A collision against a barrier would cause its momentum to decrease to 0. A change in momentum is Impulse
2) The formula for Impulse: J = f * Δt
J is Impulse
f is the force applied during the time Δt
A tough barrier would produce a smaller Δt, which means more force is applied on the car. (J is always constant)
A softer barrier would apply less force on the car, which means Δt is large.
Answer: The softer barrier is the better option
Answer:
where are the statements so i can see which one is correct
Explanation: