One side of the roof of a building slopes up at 38.0°. A roofer kicks a round, f
ID: 1659908 • Letter: O
Question
One side of the roof of a building slopes up at 38.0°. A roofer kicks a round, flat rock that has been thrown onto the roof by a neighborhood child. The rock slides straight up the incline with an initial speed of 15.0 m/s. The coefficient of kinetic friction between the rock and the roof is 0.470. The rock slides 10.0 m up the roof to its peak. It crosses the ridge and goes into free fall, following a parabolic trajectory above the far side of the roof, with negligible air resistance. Determine the maximum height the rock reaches above the point where it was kicked.
( m)
Explanation / Answer
On the roof,
a = g(-sin - µcos)
=g(-sin 380 - µcos 380) = -9.66305 m/s²
At the ridge,
V1 = [Vo² + 2as] = [15² - 2*9.66305*9.8] = 5.9669m/s
Hmax = 10*sin380+ V1²*sin² 38/2g
= 10* 0.61566 + (15)2 sin 2(38) /( 2 *9.8) = 6.1566+ 4.3512
Hmax = 10.507 m
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.