The 250-lb concrete block A is released from rest in the position shown and pulls the 400-lb log up the 30° ramp. If the coefficient of kinetic friction between the log and the ramp is 0.5, determine the velocity of the block as it hits the ground at B. 400 lb A 250 lb B 30° H₂ = 0.5 T 20′

= Q1: The 1.5-kg ball is given an initial velocity VA 2.5 in the vertical plane at position A, where the two horizontal attached springs are unstretched. The ball follows the dashed path shown and crosses point B, which is 12 cm. directly below A. Calculate the velocity of the ball at B. Each spring has a stiffness of k = 1 ª N m VA 30 cm 30 cm 12 cm A UB B Fig. 1

The 50-lb crate is subjected to the force F = 40 lb. The coefficient of kinetic friction between the crate and the ground is µk = 0.2. If the crate is initially moving to the right with a velocity of 3 ft/s, determine A) The speed of the block when t = 8 s. B) The power developed by force F at t = 8 s.

The spring has a stiffness k = 50 lb/ft and an unstretched length of 2 ft. As shown, it is confined by the plate and wall using cables so that its length is 1.5 ft. A 5-lb block is given a speed A when it is at A, and it slides down the incline having a coefficient of kinetic friction µ = 0.2. It strikes the plate and pushes it forward 0.25 ft before stopping. Neglect the mass of the plate and spring. (Figure 1), Figure k = 50 lb/ft 1.5 ft 3 ft