Q.
A mass of 3kg descending vertically downward supports a mass of 2kg by means the end of 5s, the string breaks. How much higher the 2kg mass will go further?
Acceleration of combined system, a=m1+m2m1−m2⋅g=3+23−2×9.8=1.96ms−2
Vertically upward velocity of 2kg mass at the time of breaking of string, v=at=5×1.96=9.8ms−2.
After breaking of string, mass m2 moves under gravity and go further higher through a height h, where final velocity is zero.
Hence, (0)2−(9.8)2=2×(−9.8)×h
or h=4.9m