plz solve

Asked by lovemaan5500 | 27th Dec, 2017, 01:27: PM

Expert Answer:

 
Figure shows the position of 1.5 kg and 1 kg mass at initial and final status. It can be seen from figure that string length from 1.5 kg mass to pully is changed to √5 m. Initially string length from 1.5 kg mass to pully was 1 m. Hence the height raised by 1 kg mass is (√5-1)m.
 
Let us account the energy gain/loss.
 
1.5 kg mass has lost its potential energy of height 1 m. This loss of potential energy ΔE1 = 1.5×9.8*1 = 14.7 Joules
1 kg mass has increased its potential energy of height (√5-1) metre is  ΔE2 = 1×9.8×(√5-1) = 12.11 Joules.
 
The difference of energy between ΔE1 and ΔE2 is converted into kinetic energy of 1.5 kg mass at final status.
begin mathsize 12px style 1 half cross times 1.5 cross times v squared space equals space capital delta E subscript 1 minus space capital delta E subscript 2 space equals space 2.59 space J o u l e s h e n c e space v space equals space 1.858 space m divided by s end style

Answered by  | 1st Jan, 2018, 10:34: PM