A block of mass 5 kg is (i) pushed in case (A) and (ii) pulled in case (B), by a force F = 20 N, making an angle of `30^(@)` with the horizontal, as shown in the figures. The coefficient of friction between the block and floor is `mu=0.2` . The difference between the accelerations of the block, in case (B) and case (A) will be: `(g=10ms^(-2))`

Options

A. `0.8ms^(-2)`
B. `0ms^(-2)`
C. `3.2ms^(-2)`
D. `0.4ms^(-2)`

Answer

A

Explanation

`N_(1)=50+10=60N`
`F_(4m)=0.2xx60=12N`
`F_("appred")gt12N`
`:.f_(1)=12N`
`:a_(1)=(17.32-12)/5`
`=5.32/5`
`:.a_(1)-a_(2)=-4/5`
`|a_(1)-a_(2)|=4/5=0.8m//s^(2)`
`N_(2)=50-10=40N`
`F_(4m)=0.2xx40=8N`
`F_("appled")gt8N`
`a_(2)=(17.32-8)/3`