1.

A particle moves in the xy - plane with velocity v = xhati+ythatj. At t = (xsqrt(3))/(y) the magnitudes of tangential and normal accelerations respectively are

Answer»

`(sqrt(3Y))/(2),(y)/(2)`
`(sqrt(2y))/(3),(sqrt(3y))/(2)`
`(sqrt(3y))/(2),(5y)/(2)`
`2sqrt(3y),(11y)/(sqrt(3))`

Solution :Given velocity of particle is v = `xhati+yhatj`
So`|v|=v=sqrt(x^(2)+y^(2)t^(2))`
Magnitude of tangential acceleration is
`a_(t)=(dv)/(DT)=(0+2ty^(2))/(2sqrt(x^(2)+y^(2)t^(2)))`
or `a_(t)=(ty^(2))/(sqrt(x^(2)+y^(2)t^(2)))`
Now substituting `t=(xsqrt(3))/(y)` we get
`((xsqrt(3))/(y)xxy^(2))/(sqrt(x^(2)+y^(2)xx((x^(2)xx3)/(y^(2)))))`
`implies a_(t)=(sqrt(3y))/(2)`
Also total acceleration of particle is a `=(dv)/(dt)`
`implies a=(d)/(dt)(xhati+yt hatj)`
`implies a=yhatj`
or magnitude of total acceleration is
`a=|a|=y`
Hence normal acceleration is
`a_(n)=a_("total")-a_("tangential ")`
So `a_(n)=|a_(n)|=` magnitude of normal acceleration
`=sqrt(a^(2)-a_(1)^(2))=sqrt(y^(2)-((y^(4)y^(2))/(x^(2)+y^(2)t^(2))))`
`=sqrt((x^(2)y^(2))/(x^(2)+y^(2)t^(2)))=(xy)/(sqrt(x^(2)+y^(2)t^(2))`
Now with t `=(xsqrt(3))/(y)` we get
`a_(n)=|a_(n)|=(xy)/(sqrt(x^(2)+y^(2).(3x^(2))/(y^(2))))=(xy)/(2x)=(y)/(2)`


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