problem1) Find out the required mass of block A so that when it is released from rest it moves the 5kg block B 0.75 m up along the smooth inclined plane in t= 2s. Neglect mass of the pulleys and cords
problem2) A mechanic is reinstalling a newly-sharpened blade on a lawn mower. A wedged-in block of wood at C prevents blade from rotating as the 30-lb force is applied to the wrench handle. The blade is bolted to a bracket attached to the motor shaft O, which protrudes through the bracket and blade. Find out the normal force at C. State any assumptions. Does it matter whether bolt at B is installed?
problem3) Compute maximum rate (bpm) and surface pressure (psig) which could be used for the following well without fracturing the reservoir.
depth 8,000'
fracure gradient 0.65 psi/ft
Tubing 2-3/8" 4.7#
Casing - 7" 26#
Treatment fluid 15% hcl
15% hcl viscosity at 72ηf
Well spacing 40 acres (re = 660)
Hole size = 9"
Treatment interval (h) - 50
No. of perfs 50 with 2 jspf
Formation permeability 10 md
Static bottom hole pressure 2100 psi