The minimum coefficient of friction to avoid slippage of the coin is 0.23.
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Minimum coefficient of friction</h3>
The minimum coefficient of friction can determined from the maximum speed of the coin.
ma = μmg
mv²/r = μmg
v²/r = μg
v² = μgr
μ = v²/(gr)
μ = (ωr)²/(gr)
μ = ω²r/g
μ = (7.95² x 0.035)/(9.8)
μ = 0.23
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C is the answer because contact force, is the only force mentioned that opposes the motion of the rock
Answer:
W=561.41 J
Explanation:
Given that
m = 51 kg
μk = 0.12
θ = 36.9∘
Lets F is the force applied by man
Given that block is moving at constant speed it mans that acceleration is zero.
Horizontal force = F cos θ
Vertical force = F sinθ
Friction force Fr= μk N
N + F sinθ = m g
N = m g - F sinθ
Fr = μk (m g - F sinθ)
For equilibrium
F cos θ = μk (m g - F sinθ)
F ( cos θ +μk sinθ) = μk (m g
Now by putting the values
F ( cos 36.9∘ + 0.12 x sin36.9∘)=0.12 x 51 x 10
F= 70.2 N
We know that Work
W= F cos θ .d
W= 70.2 x cos 36.9∘ x 10
W=561.41 J
The answer is A. Proton. Protons have the opposite charge to electrons, which have negative charges.