In Fig, a bullet with mass im 10 g is moving directly upward at V 800 m/s strike
ID: 2306161 • Letter: I
Question
In Fig, a bullet with mass im 10 g is moving directly upward at V 800 m/s strikes and passes through the center of mass of aM 508 block that is initially at rest. The bullet emerges from the block moving directly upward at 400m/s 10g ? Bullet a) What is the upward velocity V of the block after the collision? (A) 0.8 m/s (B) 0.4 m/s (C) 1.2 m/s To what maximum height, h, does the block then rise above its initial position? A) 0.05 m B) 0.04 m (C) 0.03 m What is the impulse J on the block? m/s (B) 4 kg m/s (C) 6 kg m/s D 2 kq m/sExplanation / Answer
here,
mass of bullet , m = 10 g = 0.01 kg
mass of block , M = 5 kg
intial speed of bullet , u1 = 800 m/s
final speed of bullet , v1 = 400 m/s
a)
let the final speed of block after the collison be v
using conservation of momentum
m * u1 = m * v1 + M * v
0.01 * 800 = 0.01 * 400 + 5 * v
v = 0.8 m/s
the upward velocity is (a) 0.8 m/s
b)
the maximum height , hm = v^2 /2g
hm = 0.8^2 /( 2 * 9.81) m
hm = 0.03 m
the maximum height is C) 0.03 m
c)
the impulse on the block , J = M * ( v - u)
J = 5 * 0.8 = 4 kg.m/s
the impulse on the block is (B) 4 kg.m/s