Hi I was wondering if I could get some help on these problems? On the first pict

Question

Hi I was wondering if I could get some help on these problems? On the first picture, I'm not sure if I had done part 2b correctly. And if you could show your work on how you did it so I can learn fr it, that would be fantastic! 2). Ablock ofmass 3kgis kept against one endofa springof HANww AmIMAm|p=0 11-1 2) Ablock ofmass 3 kg is kept against one end ofa spring of spring constant 300 N/m which is compressed by 0.2 m. The other end of the spring is fixed. This spring-mass system lies on a rough horizontal surface as shown at right. When the block is released from rest, the spring pushes it to the right as it expands. The coefficient of kinetic friction x between the block and the surface is 0.3. Ax= 0.3 2a). Draw a FBD for the block as it is pushed to the right by the spring 2b). Calculate F the force of kinetic friction acting on the block during it's motion. 2c). Calculate WFx, the work done by the force of friction while it is being pushed by the spring. 2d). Calculate vmo the speed of the block at the moment it loses contact with the spring. P251 FSI4 CMarasinghe

Explanation / Answer

2b)
Coefficient of Kinetic Friction = uk

Force of Kinetic Friciton = uk*Fn
where Fn is normal Force = m*g

Force of Kinetic Friciton =0.3 * 3 *9.8 N
Force of Kinetic Friciton = 8.82 N

2.c)
Work done by Force of Friction while it is being pushed by Spring, = Friction Force * Displacement.

W = 8.82 * 0.2 J
W = 1.76 J

2.d)
Initial Spring Potenital Energy = 0.5*k*x^2
where k = 300 N/m
x = 0.2 m
P.E = 0.5*300*0.2^2 J = 6J

Work done against Friction, = 1.76 J

As the block loses contact this Energy is converted to Kinetic Energy of block.

0.5*m*v^2 = 6 - 1.76
v = sqrt(8.48/3)
v = 1.68 m/s
Speed of the block as it loses contact with the spring, v = 1.68 m/s

Please post seperate question in seperate post.

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.