1.Answer the following work problem: a) Calculate the wok done by a force F give
ID: 1529967 • Letter: 1
Question
1.Answer the following work problem:
a) Calculate the wok done by a force F given in Cartesian coordinates as (-2 N, 3 N, 3 N) on an object when it moves from Ri = (10 m, 4 m, -2 m) to Rf = (18 m, 22 m, -5 m).
b) The object in the figure has a mass of 7.7 kg and is pulled up a slope AB by a constant external force F. The slope AB is 40 m long; the height BC is 3.2 m. There's no friction and the object's moving up with constant speed. Find the work done by the force F on the object moving it from point A to point B.
c) A block of mass m = 2.3 kg is released from rest at a height of H = 0.55 m on a curved frictionless ramp. At the foot of the ramp is a spring whose spring constant is k = 330 N/m. What's the max compression of the spring, x? After the spring reaches its max compression, it pushes the block backwards, what's the max height reached by the block?
Explanation / Answer
1)
a)
displacement r = Rf - Ri - ( (18-10) , (22-4) , (-5+2) ) = ( 8 , 18 , -3 )
work = F.r = (-2*8) + (3*18) + (3*-3) = -16 + 54 - 9 = 29 J
-----------
(b)
work done = F*s = m*g*sintheta*x = 7.7*9.8*3.2/40*40 = 241.5 J
---------
(c)
from energy conservation
gravitational PE at the top = elastic PE at the bottom
m*g*h = (1/2)*k*x^2
2.3*9.8*0.55 = (1/2)*330*x^2
x = 0.274 m
maximm height 0.55 m
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.