A uniform plank AB of length 5 m and mass 22 kg rests horizontally in equilibrium on supports at C and D. AC = 1.7 m and CD = 2.5 m. Find the reaction on the plank at D. An object of mass 6 kg is now attached to the plank at A and equilibrium is maintained. Calculate the new reaction at C.

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

Aparticle moves in the xy plane with constant acceleration. at time zero, the particle is at x = 6 m, y = 8.5 m, and has velocity ~vo = (9 m/s) ˆı + (−2.5 m/s) ˆ . the acceleration is given by ~a = (4.5 m/s 2 ) ˆı + (3 m/s 2 ) ˆ . what is the x component of velocity after 3.5 s? answer in units of m/s.