Answer:
v = - 0.096 m/s
Step-by-step explanation:
given,
mass of the robot, M = 100 Kg
mass of wrench, m = 0.8 Kg
speed of the wrench,v' = 12 m/s
recoil of the robot,v = ?
initial speed of the robot and the wrench is equal to zero
using conservation of motion
(M + m) V = M v + m v'
(M + m) x 0 = 100 x v + 0.8 x 12
100 v = -9.6
v = - 0.096 m/s
negative sign shows that velocity of robot is in opposite direction of wrench.
hence, the recoil velocity of the robot is equal to 0.096 m/s