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1. Two blocks of equal mass are each pushed (from rest) along a frictionless surface a distance d. The force applied to block B is four times that applied to block A. What is the velocity of block B, relative to that of block A, vA?
a) 4 vA
b) 2 vA
c) vA
d) vA/2
e) vA/4
2. What is the kinetic energy of block B relative to that of block A, KA?
a) 4 KA
b) 2 KA
c) KA
d) KA/2
e) KA/4
3. The same work is done compressing spring A or spring B from their equilibrium lengths. The spring constant of spring A is four times that of spring B. How much is spring B compressed relative to spring A, xA?
a) 8 xA
b) 4 xA
c) 2 xA
d) xA/2
e) xA/4
f) xA/8
4. What is the maximum force applied to spring B relative to that applied to spring A, FA?
a) 8 FA
b) 4 FA
c) 2 FA
d) FA/2
e) FA/4
f) FA/8
For 1. I figure that pushing B with 4 times the force would make it accelerate 4 times as fast, thus making the final velocity 4 times as fast as the velocity of block A if they both start at rest. So I chose a)
For 2. I figure that since the velocity of B is 4 times larger than the velocity of A, then the KE = 1/2 m*v2 would make the KE of B 4 times larger than the KE of A, so I chose a) again.
For 3. I figure that kA is 4kB. If the work for both is equal, then F*dA = F*dB, and since kA = 4kB, then B is compressed 4 times as much, so I chose b). I am unsure about this one.
For 4. I'm kind of confused...
Any help at all would be appreciated!
a) 4 vA
b) 2 vA
c) vA
d) vA/2
e) vA/4
2. What is the kinetic energy of block B relative to that of block A, KA?
a) 4 KA
b) 2 KA
c) KA
d) KA/2
e) KA/4
3. The same work is done compressing spring A or spring B from their equilibrium lengths. The spring constant of spring A is four times that of spring B. How much is spring B compressed relative to spring A, xA?
a) 8 xA
b) 4 xA
c) 2 xA
d) xA/2
e) xA/4
f) xA/8
4. What is the maximum force applied to spring B relative to that applied to spring A, FA?
a) 8 FA
b) 4 FA
c) 2 FA
d) FA/2
e) FA/4
f) FA/8
For 1. I figure that pushing B with 4 times the force would make it accelerate 4 times as fast, thus making the final velocity 4 times as fast as the velocity of block A if they both start at rest. So I chose a)
For 2. I figure that since the velocity of B is 4 times larger than the velocity of A, then the KE = 1/2 m*v2 would make the KE of B 4 times larger than the KE of A, so I chose a) again.
For 3. I figure that kA is 4kB. If the work for both is equal, then F*dA = F*dB, and since kA = 4kB, then B is compressed 4 times as much, so I chose b). I am unsure about this one.
For 4. I'm kind of confused...
Any help at all would be appreciated!