This answer has not been graded yet. Question Part Points Submissions Used A sma
ID: 2142704 • Letter: T
Question
This answer has not been graded yet.
Question Part Points Submissions Used A small rock with mass 0.23 kg is released from rest at point A, which is at the top edge of a large, hemispherical bowl with radius R = 0.49 m (see figure). Assume that the size of the rock is small compared to R, so that the rock can be treated as a particle, and assume that the rock slides rather than rolls. The work done by friction on the rock when it moves from point A to point B at the bottom of the bowl has magnitude 0.21 J. Between points A and B, how much work is done on the rock by the following. the normal force gravity What is the speed of the rock as it reaches point B? Of the three forces acting on the rock as it slides down the bowl, which (if any) are constant? (Select all that apply.) gravitynormal force friction force Which are not constant? Just as the rock reaches point B, what is the normal force on it due to the bottom of the bowl?Explanation / Answer
(a) 1.the normal force will always be perpendicular to the motion so work done by normal force = 0
2. work done by gravity = m*g*R
= 0.23*9.8*0.49
= 1.104 J
(b) work done by gravity + work done by friction = change in kinetic energy
=> 1.104 + (-0.21) = 1/2(m*v^2) - 0
=> 0.89 = 0.5(0.23*v^2)
=> v^2 = 7.778
=> v = 2.789 m/s
(c)1. 'force of gravity' will remain constant.
2. normal force & friction will not remain constant. because normal will remain changing as the particle moves towards bottom, due to centripetal force acting on the partical & because of normal force , friction will also remain changing due to its dependency on normal force)
(d) normal at the bottom = mg + (m*v^2)/R
= 2.254 + 3.651
= 5.905 N
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.