Answer:
Paul B. MacCready, 81; inventor of human-powered aircraft, other innovations. Paul B. MacCready, the Caltech-trained scientist and inventor who created the Gossamer Condor -- the first successful human-powered airplane -- as well as other innovative aircraft, has died. He was 81.
Explanation:
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
to learn more about Coefficient of friction go to - brainly.com/question/14121363
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<span>Lifting an object increases the gravitational potential energy of the system. If you release the object, that potential energy will be transformed into the energy of an object in motion which is termed as the kinetic energy as it falls toward earth. Hope this helps.</span>
