Question

A sphere of mass 2kg and radius 0.5 m is rolling with an initial speed of 1 ms^–1 goes up an inclined plane which makes an angle of 30° with the horizontal plane, without slipping. How low will the sphere take to return to the starting point A ? 

 

(1) 0.60 s

(2) 0.52 s

(3) 0.57 s

(4) 0.80 s

 

Answer 1

 Correct option is (3) 0.57 s 

\( a=\frac{g\sin \theta}{1+\frac{I}{mR^2}}  \)

\( \frac{5}{7}×\frac{10}{2} =\frac{25}{7}\)

\( t=\frac{2v_0}{a}=\frac{2×1×7}{25} \)

=0.56 s