i'm stuck on that question also
Answer:

Explanation:
given,
width of door dimension = 1 m
mass of door = 15 Kg
mass of bullet = 10 g = 0.001 Kg
speed of bullet = 400 m/s


a) from conservation of angular momentum





Answer:
8400m
Explanation:
The engine that falls off would have the same constant horizontal velocity as the airplane's when if falls off if we ignore air resistance. So it would have a horizontal velocity of 280m/s for 30seconds before it hits the ground.
Therefor the horizontal distance the engine travels during its fall is
280 * 30 = 8400m
Answer: 900
Explanation: Force equals mass x acceleration F=M×A
Answer:
v = 1.4 m /s
Explanation:
We shall apply law of conservation of mechanical energy
The kinetic energy of dart and block is converted into potential energy of both dart and block .
1 /2 (m+M) v² = ( m +M) gH
.5 x v² = 9.8 x .1
= v² = 1.96
v = 1.4
v = 1.4 m /s