Answer:
β = 114 db
Explanation:
The intensity of sound in decibles is
β = 10 log 
in most cases Io is the hearing threshold 1 10-12 W / cm²
let's calculate the intensity of each instrument
I / I₀ = 10 (β / 10)
I = I₀ 10 (β / 10)
trumpet
I1 = 1 10⁻¹² 10 (94/10)
I1 = 2.51 10⁻³ / cm²
Thrombus
I2 = 1 10⁻¹² 10 (107/10)
I2 = 5.01 10-2 W / cm²
low
I3 =1 1-12 (113/10) W/cm²
I3 = 1,995 10-1 W / cm²
when we place the three instruments together their sounds reinforce
I_total = I₁ + I₂ + I₃
I_ttoal = 2.51 10-3 + 5.01 10-2 + 1.995 10-1
I_total = 0.00251 + 0.0501 + 0.1995
I_total = 0.25211 W / cm²
let's bring this amount to the SI system
β = 10 log (0.25211 / 1 10⁻¹²)
β = 114 db
Answer:

Explanation:
We are asked to find the final velocity of the boat.
We are given the initial velocity, acceleration, and time. Therefore, we will use the following kinematic equation.

The initial velocity is 2.7 meters per second. The acceleration is 0.15 meters per second squared. The time is 12 seconds.
= 2.7 m/s - a= 0.15 m/s²
- t= 12 s
Substitute the values into the formula.

Multiply the numbers in parentheses.




Add.

The final velocity of the boat is <u>4.5 meters per second in the positive direction.</u>
Answer:
The potential energy of the hiker is
.
Explanation:
Given that,
Mass of the hiker, m = 61 kg
Height above sea level, h = 1900 m
We need to find the potential energy associated with a 61-kg hiker atop New Hampshire's Mount Washington. The potential energy is given by :

g is the acceleration due to gravity

So, the potential energy of the hiker is
. Hence, this is the required solution.
Answer:
F = 4399 KN
Explanation:
given,
mass of automobile = 890 kg
initial speed = 48 km/h
= 48 × 0.278 = 13.34 m/s
using equation of motion
v² = u² + 2 a × s
0 = 13.34² - 2 a ×0.018

a = 4943.21 m/s²
F = m × a
F = 890 × 4943.21
F = 4399456.9 N
F = 4399 KN
hence, the Net force is F = 4399 KN