Answer: 3.84dB
Explanation:
Since person A is talking 1.2dB louder than B, we will have
A = 1.2B... (1)
Similarly, person C is talking 3.2 dB louder than person A, we have
C = 3.2A... (2)
From equation 1, B = A/1.2... (3)
To get the ratio of the sound intensity of person C to the sound intensity of person B, we will divide equation 2 by 3 to give
C/B = 3.2A/{A/1.2}
C/B = 3.2A×1.2/A
C/B = 3.2×1.2
C/B = 3.84dB
Answer:
The force pulling the roller along the ground is 128.55 N
Explanation:
A force of 200 N acting at an angle of 50° with the ground level
This force is pulled a garden roller
We need to find the force pulling the roller along the ground
The force that pulling the roller along the ground is the horizontal
component of the force acting
→ The force acting is 200 N at direction 50° with ground (horizontal)
→ The horizontal component = F cosФ
→ F = 200 N , Ф = 50
→ The horizontal component = 200 cos(50) = 128.55 N
128.55 N is the horizontal component of the force that pulling the
roller along the ground
<em>The force pulling the roller along the ground is 128.55 N</em>
Answer:
B - Velocity
Explanation:
Velocity definition: “The speed of something in a given direction.”
Answer:
8.91 J
Explanation:
mass, m = 8.20 kg
radius, r = 0.22 m
Moment of inertia of the shell, I = 2/3 mr^2
= 2/3 x 8.2 x 0.22 x 0.22 = 0.265 kgm^2
n = 6 revolutions
Angular displacement, θ = 6 x 2 x π = 37.68 rad
angular acceleration, α = 0.890 rad/s^2
initial angular velocity, ωo = 0 rad/s
Let the final angular velocity is ω.
Use third equation of motion
ω² = ωo² + 2αθ
ω² = 0 + 2 x 0.890 x 37.68
ω = 8.2 rad/s
Kinetic energy,
K = 0.5 x 0.265 x 8.2 x 8.2
K = 8.91 J