The answer OC. It can be changed only if all scientists approve the change
The answer to this question is option 2
Answer with explanation:
We are given that
Mass of ball,
75 g=
1 kg=1000 g
Height,

Horizontal velocity,
Mass of plate
a.Initial velocity of plate,
Velocity before impact=
Where 
Velocity after impact,
According to law of conservation of momentum

Substitute the values



Velocity of plate=1.69 m/s
b.Initial energy=
Final energy=
Final energy=
Energy lost due to compact=Initial energy-final energy=1.326-1.162=0.164 J
T = 3.5 secs
Velocity (v) = g * t = 10 m/s^2 * 3.5 sec = 35 m/s
Answer:
It includes earthwork, trenching, wall shafts, tunneling and underground
Explanation: