50 A 10 kg block is pushed against a spring with a spring constant of 100 N/m, compressing the spring by 0.4 m. The block is then released from rest. Assuming no friction, what is the maximum speed of the block after being released from the spring?
A) 2.0 m/s
B) 3.0 m/s
C)4.0 m/s
D)5.0 m/s
E) 6.0 m/s
Anyone knows how to solve this?
The correct answer is C
Sorry my bad, I think we should solve it with Hooke’s Law.
F = kx
F = 100(0.4)
F= 40J
If 40J of energy is used in total,
F = ma
40 = 10(a)
a=4 m/s2
If initial velocity is 0 and the acceleration is 4, the maximum speed after 1 seconds is 4 m/s.
But I think the questions should’ve specifically asked for the speed after 1 seconds.
consider pressing the block against the spring. the force (f=-kx) exerted on the spring is 40 N (100N/m times 0.4m is 40 N). we also know f=ma, substituting f with 40N and m with 10 kg you get 4,0m/s which is also the maximum velocity the block will reach