u1 =initial speed of the bullet= 490.86 m/sec is the correct answer
using conservation of linear momentum, we write
m1u1 + m2 u2 = m1 v1 + m2v2
where u1 ,u2 are the initial velocities of masses m1 and m2
where v1 ,v2 are the final velocities of masses m1 and m2
hence (.007) (u1) + 1.5(0) = 1.5(v2) + .007(200).........................1
using energy equation for the block alone we get
mgh = 1/2 m (v2)^2
hence 9.8(.094) =.5 (v2)^2
hence v2=1.357 m/sec
substitute it in 1
we get,
u1 =initial speed of the bullet= 490.86 m/sec
To learn about conservation of linear momentum
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