Spring on inclined plane with a Block

[masterchiefo]

Homework Statement

A block of mass m = 4 kg, is held at rest on a spring (point A), spring constant k =
500 N / m, compressed by a distance AB = .DELTA.L as shown in Figure 3. When the block is freed ,
it reaches the point B ( non-deformed position of the spring ) with a velocity of VB = 5 m / s. assume
the coefficient of kinetic friction between the block and the incline is μk = 0.15 , determine :
a) compression of the spring ;
b) the distance traveled by the block to stop, point C (measured from point B);

Problem original drawing:
http://i.imgur.com/i98xq8J.png

Homework Equations

∑Fy = m*ay
F_k = μk * N
W_i->f = F(cos(angle)*DELTA X)
U_gi + U_ei + (W_i->f) + 1/2 *m*v_i² = U_gf + U_ef + 1/2*m*vf²

The Attempt at a Solution

My drawing of the problem:
The spring become uncompressed at B.
http://i.imgur.com/Db1HwA0.jpg

v = speed (m/s)

∑Fy = m*ay
ay = 0 // m = 4kg
N - W*cos(35) = m*ay => N - (4*9.81)*cos(35) = 4*0
N = 32.1435N

F_k = μk * N
F_k = 0.15 * 32.1435N
F_k = 4.82153N

W_i->f = F(cos(angle)*DELTA X)
W_i->f = 4.82153N(cos(35)*DELTA X)

U_gi + U_ei + (W_i->f) + 1/2 *m*v_i² = U_gf + U_ef + 1/2*m*vf²

U_gi = 0J
U_ei = 1/2 * K * X_sf²
W_i->f = 4.82153N(cos(35)*DELTA X)
1/2 *m*v_i² = 0 since speed initial is 0m/s
U_gf = m*g*h_f = 4Kg*9.81* h_f*sin(35)
U_ef = 0J
1/2*m*vf² = 1/2*4Kg*5m/s²

I am stuck here... :(

 

[SammyS]

Homework Statement

A block of mass m = 4 kg, is held at rest on a spring (point A), spring constant k =
500 N / m, compressed by a distance AB = .DELTA.L as shown in Figure 3. When the block is freed ,
it reaches the point B ( non-deformed position of the spring ) with a velocity of VB = 5 m / s. assume
the coefficient of kinetic friction between the block and the incline is μk = 0.15 , determine :
a) compression of the spring ;
b) the distance traveled by the block to stop, point C (measured from point B);

Problem original drawing:

Homework Equations

∑Fy = m*ay
F_k = μk * N
W_i->f = F(cos(angle)*DELTA X)
U_gi + U_ei + (W_i->f) + 1/2 *m*v_i² = U_gf + U_ef + 1/2*m*vf²

The Attempt at a Solution

My drawing of the problem:
The spring become uncompressed at B.
http://i.imgur.com/Db1HwA0.jpg

v = speed (m/s)

∑Fy = m*ay
ay = 0 // m = 4kg
N - W*cos(35) = m*ay => N - (4*9.81)*cos(35) = 4*0
N = 32.1435N

F_k = μk * N
F_k = 0.15 * 32.1435N
F_k = 4.82153N

W_i->f = F(cos(angle)*DELTA X)
W_i->f = 4.82153N(cos(35)*DELTA X)

U_gi + U_ei + (W_i->f) + 1/2 *m*v_i² = U_gf + U_ef + 1/2*m*vf²

U_gi = 0J
U_ei = 1/2 * K * X_sf²
W_i->f = 4.82153N(cos(35)*DELTA X)
1/2 *m*v_i² = 0 since speed initial is 0m/s
U_gf = m*g*h_f = 4Kg*9.81* h_f*sin(35)
U_ef = 0J
1/2*m*vf² = 1/2*4Kg*5m/s²

I am stuck here... :(

You can post those links as images if they're not too large, like I did with one of yours

Otherwise, download them to your own file system, then upload to PF & show a thumbnail.