CE 298

Exam 2 Problem 1 (20%)

A 6 kg block B starts from rest and slides on the 10 kg wedge A, which is supported by a horizontal surface. Neglecting friction, determine the velocity of B relative to A when the velocity of A reaches 0.5 m/sec.

Problem 2 (25%)

A 2-lb sphere falls freely and impacts upon a 10-lb wedge with a velocity of 10 ft/sec. Assuming all surfaces to be frictionless, and assuming an elastic impact between the sphere and the wedge and a coefficient of restitution between the wedge and the ground of e=0.75, determine the velocities of the sphere and wedge immediately after impact.

Problem 3 (30%)

The inner spool, with radius 1 m, of a gear with radius 2 m, is rolling without slip on a fixed gear rack as shown. The inner spool is pulled at the instant shown at a speed of 10 m/sec. and at an acceleration of 2 m/sec2 by a cord wrapped around as shown. Find the acceleration of point P.

2 m/sec2

Problem 4 (25%)

The block shown has a mass of 0.5 kg and moves within the smooth vertical slot. If the block starts from rest, at position A, when the attached spring is unstretched, determine the constant vertical force F which must be applied to the cord so that the block, at position B, attains a speed of 2.5 m/sec. Neglect the mass of the cord and pulley. Use sB= 0.15 m.