CAN ANYONE PLS HELP me, 25 points! Question (1) dt= -3 t+6 is the equation of motion for a moving object, at what instant the object will reverse its direction of motion?

Hint: Substitute d=0 m in the above equation and solve for t.

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.