Question

1. A caveman applies a horizontal force of 800 N at height of 0.1 m above the center of a large spherical boulder of mass 400 kg and radius of 0.5 m (treat as a sphere: Icm = 2/5 mr2 ). Assume the sphere starts from rest and rolls horizontally without slipping.

a) Draw a free-body diagram and label all the forces at their point of contact.

b) Write equations applying Newton’s 2nd law for rotation and translation for the boulder.

c) Solve for the translational and angular acceleration of the boulder.

d) What is the minimum coefficient of static friction to prevent slipping?

e) If the boulder were replaced with a hollow hoop of the same mass and radius (assume no slipping), how would that have affected i) the angular acceleration ii) the linear acceleration iii) the static friction needed not to slip

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Answer 1