Block A in the figure (Figure 1) has mass 1.00 kg, and block B has mass 3.00 kg.

Question

Block A in the figure (Figure 1) has mass 1.00 kg, and block B has mass 3.00 kg. The blocks are forced together, compressing a spring S between them; then the system is released from rest on a level, frictionless surface. The spring, which has negligible mass, is not fastened to either block and drops to the surface after it has expanded. Block B acquires a speed of 1.60 m/s .

Part A

What is the final speed of block A?

SubmitMy AnswersGive Up

Part B

How much potential energy was stored in the compressed spring?

SubmitMy AnswersGive Up

Provide FeedbackContinue

Figure 1 of 1

Block A in the figure (Figure 1) has mass 1.00 kg, and block B has mass 3.00 kg. The blocks are forced together, compressing a spring S between them; then the system is released from rest on a level, frictionless surface. The spring, which has negligible mass, is not fastened to either block and drops to the surface after it has expanded. Block B acquires a speed of 1.60 m/s .

Part A

What is the final speed of block A?

v =   m/s  

SubmitMy AnswersGive Up

Part B

How much potential energy was stored in the compressed spring?

U =   J  

SubmitMy AnswersGive Up

Provide FeedbackContinue

Figure 1 of 1

Explanation / Answer

Part A: mA =1 kg , uA =0 , mB = 3 kg , bB =0 , vB =1.6 m/s

From conservation of momentum

mAuA+mBuB = mAvA+mBvB

0+0 = 1*vA + 3*1.6

vA = -4.8 m/s

Part B:

From conservation of energy

Potential energy in spring = kinetic energy of system

U = (1/2)mAvA^2 +(1/2)mBvB^2

U = (0.5*1*4.8*4.8) +(0.5*3*1.6*1.6)

U =15.36 J

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

---