Block A has a constant velocity of 48 in./s to the left. For the position shown, determine the velocity of block B. (Note: The radius of the pulley may be neglected.)
Solution
For the triangle of sides 2ft and 1.5 ft :
let 2ft side = x (variable )
let 1.5ft side = c constant through out the motion.
Hypotenuse : s^2 = c^2 + x^2 also a variable
differentiate wrt t
s*ds/dt = x*dx/dt
dx/dt = 48in/s at x = 2ft and s = 2.5ft
ds/dt = 38.4ft/s
Since string is inextensible ds/dt will be same as the velocity of block B
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Block A has a constant velocity of 48 in--s to the left- For the posit.docx
1. Block A has a constant velocity of 48 in./s to the left. For the position shown, determine the
velocity of block B. (Note: The radius of the pulley may be neglected.)
Solution
For the triangle of sides 2ft and 1.5 ft :
let 2ft side = x (variable )
let 1.5ft side = c constant through out the motion.
Hypotenuse : s^2 = c^2 + x^2 also a variable
differentiate wrt t
s*ds/dt = x*dx/dt
dx/dt = 48in/s at x = 2ft and s = 2.5ft
ds/dt = 38.4ft/s
Since string is inextensible ds/dt will be same as the velocity of block B
