A light spring of force constant 3.85N/m is compressed by 8.00 cmand held between a .250 kg block on the left and a .500 kg block onthe right. Both blocks are at rest on a horizontal surface. Theblocks are released simultaneously so that the spring tends to pushthem apart. What is the maximum velocity each block attains if thecoefficient of kinetic friction between each block and the surfaceis:
A) 0
B) .100
C) .463
Assume that the coefficient of static friction is larger than thatfor kinetic friction
Hint:
In the part where there is friction you know that ;
-fk.d= (Uf+Kf)- (Ui+Ki)
d= 0.08-x ; (0.08 being the compressed distance)
You have to get the frictions for the two blocks, you already knowthe force of the spring.
For the heavier block the force of the spring will be smaller thanthe friction fk, so the heavier block will stand still, and thefrictional force exerted by the floor change the momentum of thetwo blocks system. The light block will gain speed as long as thespring force is larger than the friction force, that is until thespring compresses and the magnitude of the spring force:
Fs= kx =fk (lighter spring)
Answers:
A) -.256 m/s and .128 m/s
b) .0642 m/s and 0
c) 0 and 0
A light spring of force constant 3.85N/m is compressed by 8.00 cmand held between a .250 kg block on the left and a .500 kg block onthe right. Both blocks are at rest on a horizontal surface. Theblocks are released simultaneously so that the spring tends to pushthem apart. What is the maximum velocity each block attains if thecoefficient of kinetic friction between each block and the surfaceis:
A) 0
B) .100
C) .463
Assume that the coefficient of static friction is larger than thatfor kinetic friction
Hint:
In the part where there is friction you know that ;
-fk.d= (Uf+Kf)- (Ui+Ki)
d= 0.08-x ; (0.08 being the compressed distance)
You have to get the frictions for the two blocks, you already knowthe force of the spring.
For the heavier block the force of the spring will be smaller thanthe friction fk, so the heavier block will stand still, and thefrictional force exerted by the floor change the momentum of thetwo blocks system. The light block will gain speed as long as thespring force is larger than the friction force, that is until thespring compresses and the magnitude of the spring force:
Fs= kx =fk (lighter spring)
Answers:
A) -.256 m/s and .128 m/s
b) .0642 m/s and 0
c) 0 and 0
