A mass of `1kg` attached to one end of a string is first lifted up with an acceleration `4.9m//s^(2)` and then lowered with same acceleration What is the ratio of tension in string in two cases .

Explanation

When mass is lifted up with acceleration `4.9m//s^(2)`
`T_(1)=m(g+a)=1(9.8+4.9)=14.7N`
When mass is lowered with same acceleration
`T_(2)=m(g-a)=1(9.8-4.9)=4.9N`
`therefore (T_(1))/(T_(2))=(14.7)/(4.9)=3:1`