A van accelerates uniformly down an inclined hill going from reast to `30m//s` in `6s`. During the acceleration , a toy of mass `m=0.1kg` hangs by a light string from the van's ceiling . The acceleration is such that string remains perpendicular to the ceiling. `(` Take `g=10m//s^(2))`

The tension n the string is

Options

A. `1.0N`
B. `0.5N`
C. `(sqrt(3))/(2)N`
D. `sqrt(3)N`

Answer

C

Explanation

Acceleration of the van `=(30)/(6)=5 m//s^(2)`
`g sin theta =a`
`rArr sin theta =(1)/(2)`
`rArr theta=30^(@)`
Tension
`T=mg cos theta =(sqrt(3))/(2)N`