1.) Consider a 20.0 kg block at rest on a horizontal table top. The coefficient
ID: 306828 • Letter: 1
Question
1.) Consider a 20.0 kg block at rest on a horizontal table top. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.25 between block and the table top. The block is tied by a massless string that stretches horizontally from the block over a frictionless, massless pulley to an empty bucket hanging vertically over the side of the table. The bucket has a mass of 5.0 kg. A) If sand is slowly added to the bucket how much sand will be added before the block starts moving? Sources: B.) Once the block begins to move what is its acceleration?Explanation / Answer
1. (A) on 20kg block, N = M g = 20 x 9.8 = 196 N
and f_max = us N = 0.5 x 196 = 98 N
So we need tension equal to 98 N , to strat the block to move.
T = m g
98 = m (9.8) => m = 10 kg
mass to be added = 10 - 5 = 5 kg .......Ans
(B) when it starts moving then kinetic friction will act on it.
uk = uk N = 39.2
a = (98 - 49)/10 = 4.9 m/s^2
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.