2 An object is attached to a trolley of mass 0.80 kg, which is then pushed into an identical stationary trolley at a speed of 1.1 m/s.
The two trolleys couple together and move at a velocity of 0.70 m/s
after the collision. Calculate the mass of the object. [6 marks]​

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?