A block of metal of mass 2 kg on a horizontal table is attached to a mass of `0.45` kg of by a light string passing over a frictionless pulley at the edge of the table . The block is subjected to a horizontal force by allowing the `0.45` kg mass of fall . The coefficient of sliding friction between the block and table is `0.2`

Calculate (a) the initial acceleration , (b) the tension in the string , (c ) the distance the block would continue to move if , after 2 s of motion . the string should break

Explanation

Here, `m_(1) = 0.45 kg`
`m_(2) = 2kg`
`m= 0.2 `
(a) Initial acceleration ,
`a = ((m_(1)-mum_(2))/(m_(1)+m_(2)))g`
`= [(0.45 - 0.2xx2)/(0.45+2)]xx9.8`
` a = 0.2 ms^(-2)`
(b) From fig , we have
`T - f = m_(2) a `
`T - 3.92 = 2 xx 0.2 `
` [ f = mumg = 0.2 xx 2xx 9.8] `
= 3.92 N
` rArr N = 0.4 + 3.92 = 4.32 N `