A cheetah , weighing 150 kg , chases a deer , weighing 30 kg , in a straight path . The speed of the cheetah is 20 m/s and that of the deer is 25 m/s . The approximate speed of the centre of mass of the pair is

A cheetah , weighing 150 kg , chases a deer , weighing 30 kg , in a st

1.	A cheetah , weighing 150 kg , chases a deer , weighing 30 kg , in a straight path . The speed of the cheetah is 20 m/s and that of the deer is 25 m/s . The approximate speed of the centre of mass of the pair is
Answer» SOLUTION :Here `m_(1) = 150` KG , `m_(2) = 30` kg `v_(1) = 20` m/s , `v_(2) = 25` m/s Speed of the centre of mass is `v_(CM) = (m_(1) v_(1) + m_(2) v_(2))/(m_(1) + m_(2))` `= ((150 kgxx 20 m//s)+ (30 kg xx 25 m//s))/(150 kg + 30 kg)` `= (3750 kg m//s)/(180 kg) = 21` m/s