Answer:
vibration
Explanation:
When the school bell vibrates, it forces the adjacent particles in air to vibrate. ... As the bell continues to move forward and backward, it produces a series of compressions and rarefactions. This makes the sound of a bell propagate through air.
Answer:
Water
Explanation:
The speed of light in water is about 230 million m/s.
The coefficient of friction is 0.5.
<h3>What is Coefficient of friction?</h3>
The ratio of friction force to normal force is known as the coefficient of friction (COF), which has no dimensions. Those materials are said to as lubricous if their COF is less than 0.1. Surface roughness and COF are dependent on the composition of the materials.
Initial velocity, u=30m/s
time taken = 6s
Final velocity, v=0
Acceleration of friction, a=μg=10μms⁻²
Apply first kinematic equation of motion,
v - u = at
0 - 30 = (-10μms⁻²) × 6
-30 = -60μ
μ = 1/2
μ = 0..5
Hence, coefficient of friction is 0.5
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