A spring (k = 210 N/m) is fixed at the top of a frictionless plane inclined at a
ID: 1435371 • Letter: A
Question
A spring (k = 210 N/m) is fixed at the top of a frictionless plane inclined at angle = 32 °. A 1.6 kg block is projected up the plane, from an initial position that is distance d = 0.60 m from the end of the relaxed spring, with an initial kinetic energy of 30 J. (a) What is the kinetic energy of the block at the instant it has compressed the spring 0.20 m? (b) With what kinetic energy must the block be projected up the plane if it is to stop momentarily when it has compressed the spring by 0.50 m?
Explanation / Answer
A.
y = d*sin A = (0.6+0.2)*sin 32 deg = 0.4239
By energy conservation
Ki + Ui = Kf + Uf
30 + 0 = Kf + mgy + 0.5*kx^2 = Kf + 1.6*9.81*0.4239 + 0.5*210*0.2^2
30 = kf + 10.8535
kf = 19.1465 J
B. Ki + Ui = Kf + Uf
Ki + 0 = 0 + mgy1 + 0.5*kx^2
y1 = 1.1*sin 32 deg = 0.5829
Ki = 1.6*9.81*0.5829 + 0.5*210*0.5^2
Ki = 35.39 J
comment below if you have any doubt.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.