The time taken by a block of wood (initially at rest) to slide down a smooth inclined plane $9.8\, m$ long (angle of inclination is ${30^o}$) is.........$sec$
A
$0.5$
B
$2$
C
$4$
D
$1$
The time taken by a block of wood (initially at rest) to slide down a smooth inclined plane $9.8\, m$ long (angle of inclination is ${30^o}$) is.........$sec$
For one dimensional motion along a plane
$S = ut + \frac{1}{2}a{t^2}$$ \Rightarrow 9.8 = O + \frac{1}{2}$ $g\sin {30^o}{t^2}$
$⇒$ $t = 2\sec $