As shown in the figure,a 1.45-kg block is held in place against the spring by a 21-N horizontal external force.The external force is removed,and the block is projected with a velocity $v 1 = 1.2 \mathrm {~m} / \mathrm { s }$ as it separates from the spring.The block descends a ramp and has a velocity $v _ { 2 } = 2.1 \mathrm {~m} / \mathrm { s }$ at the bottom.The track is frictionless between points A and B.The block enters a rough section at B,extending to E.The coefficient of kinetic friction between the block and the rough surface is 0.29.The velocity of the block is $v _ { 3 } = 1.4 \mathrm {~m} / \mathrm { s }$ at C.The block moves on to D,where it stops.How much of the mechanical energy was converted to internal energy between points B and C?
A)-1.8 J
B)-3.6 J
C)-14 J
D)-6.4 J
E)-7.0 J

Question

As shown in the figure,a 1.45-kg block is held in place against the spring by a 21-N horizontal external force.The external force is removed,and the block is projected with a velocity $v 1 = 1.2 \mathrm {~m} / \mathrm { s }$ as it separates from the spring.The block descends a ramp and has a velocity $v _ { 2 } = 2.1 \mathrm {~m} / \mathrm { s }$ at the bottom.The track is frictionless between points A and B.The block enters a rough section at B,extending to E.The coefficient of kinetic friction between the block and the rough surface is 0.29.The velocity of the block is $v _ { 3 } = 1.4 \mathrm {~m} / \mathrm { s }$ at C.The block moves on to D,where it stops.How much of the mechanical energy was converted to internal energy between points B and C? 
A)-1.8 J 
B)-3.6 J 
C)-14 J 
D)-6.4 J 
E)-7.0 J

Quizplus · Accepted Answer

The Answer of As shown in the figure,a 1.45-kg block is held in place against the spring by a 21-N horizontal external force.The external force is removed,and the block is projected with a velocity $v 1 = 1.2 \mathrm {~m} / \mathrm { s }$ as it separates from the spring.The block descends a ramp and has a velocity $v _ { 2 } = 2.1 \mathrm {~m} / \mathrm { s }$ at the bottom.The track is frictionless between points A and B.The block enters a rough section at B,extending to E.The coefficient of kinetic friction between the block and the rough surface is 0.29.The velocity of the block is $v _ { 3 } = 1.4 \mathrm {~m} / \mathrm { s }$ at C.The block moves on to D,where it stops.How much of the mechanical energy was converted to internal energy between points B and C? 
A)-1.8 J 
B)-3.6 J 
C)-14 J 
D)-6.4 J 
E)-7.0 J

As Shown in the Figure,a 1 v1=1.2 m/sv 1 = 1.2 \mathrm {~m} / \mathrm { s }v1=1.2 m/s

As Shown in the Figure,a 1 $v 1 = 1.2 \mathrm {~m} / \mathrm { s }$