Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Only need part D AND E! A thin-walled, hollow spherical shell of mass m and radi

ID: 1977251 • Letter: O

Question

Only need part D AND E!

A thin-walled, hollow spherical shell of mass m and radius r starts from rest and rolls without slipping down the track shown in the figure . Points A and B are on a circular part of the track having radius R. The diameter of the shell is very small compared to h_0 and R, and rolling friction is negligible.

A) What is the minimum height h_0 for which this shell will make a complete loop-the-loop on the circular part of the track?

B) How hard does the track push on the shell at point B, which is at the same level as the center of the circle?

C) Suppose that the track had no friction and the shell was released from the same height h_0 you found in part (a). Would it make a complete loop-the-loop?

D) In part (c), how hard does the track push on the shell at point A, the top of the circle?

E) How hard did the track push on the shell at point A in part (a)?

Explanation / Answer

in   part (c) mgh0 = mg (2R) + (1/2) mv2      from the part (a) h0 = (17/6) R                 mg  (17/6) R - mg (2R) =(1/2) mv2                  mg (   (17/6) R - 2R) = (1/2) mv2      gives v2 = ( 5/3) gR          F = ma at point A gives           mg+ n = mv2/r                n = m (( v2/R) - g) = ( 2/3) mg e) in part (a) n = 0 since at this point gravity alone supplies the net downward force that is required for the circular motion.      from the part (a) h0 = (17/6) R                 mg  (17/6) R - mg (2R) =(1/2) mv2                  mg (   (17/6) R - 2R) = (1/2) mv2      gives v2 = ( 5/3) gR          F = ma at point A gives           mg+ n = mv2/r                n = m (( v2/R) - g) = ( 2/3) mg e) in part (a) n = 0 since at this point gravity alone supplies the net downward force that is required for the circular motion.