Amassless spring with force constant
245 n/m is fastened at its left end to a vertical
wall, as shown below.
the acceleration of gravity is 9.8 m/s
2
.
9 kg 3 kg
245 n/m
initially, the 9 kg block and 3 kg block rest
on a horizontal surface with the 9 kg block in
contact with the spring (but not compressing
it) and with the 3 kg block in contact with the
9 kg block. the 9 kg block is then moved to
the left, compressing the spring a distance of
0.7 m, and held in place while the 3 kg block
remains at rest as shown below.
9 kg 3 kg
k 0.7 m
determine the elastic energy u stored in
the compressed spring.
answer in units of j.
013 (part 2 of 4) 10.0 points
the 9 kg block is then released and accelerates
to the right, toward the 3 kg block. the
surface is rough and the coefficient of friction
between each block and the surface is 0.5 . the
two blocks collide, stick together, and move
to the right. remember that the spring is not
attached to the 9 kg block.
find the speed of the 9 kg block just before
it collides with the 3 kg block.
answer in units of m/s.
014 (part 3 of 4) 10.0 points
find the final speed of both blocks (stuck
together) just after they collide.
answer in units of m/s.
015 (part 4 of 4) 10.0 points
find the horizontal distance the blocks move
before coming to rest.
answer in units of m