Most Important Selected Qs for JEE AdvancedPhysicsLaws of Motion
At t =0 , a force F = at ^2 is applied to a small body of mass m at an angle resting on a smooth horizontal plane
Options
- Avelocity of the body at the moment it brakes off the plane is
- Bthe distance travelled by the body before breaking off the plane is mg ^2 12 a .
- CIts acceleration at the time of breaking off the plane is g .
- DTime at which it breaks off the plane is mg a .
Correct answer
D. Time at which it breaks off the plane is mg a .
Step-by-step solution
For breaking off the plane: aligned & F = mg & a t ₀^2 = mg & t ₀= mg a . aligned Speed at time of breaking off. aligned & v = ₀^ b at ^2 ~m dt = at t ₀^2 3 ~m & = a 3 ~m mg a mg a & = mg ^3 9 ^2 & a = F ~m = at ₀^2 ~m = amg a ~m & = g . & s= vdt = ₀^b t ^3 3 ~m dt & = a 12 m t₀^4= a 12 m m^2 g^2 a^2 ^2 & = mg ^2 12 a . aligned