Question

28. A projectile is projected at 10 ms by making at an angle 60° to the horizontal. After some time, its velocity (in ms-1) makes an angle of 30° to the horizontal. Its speed at this instant is (b) 3 (d) 53

NEET/Medical Exams

Physics

Solution

267

5.0 (1 ratings)

Gluen: ( u=10 mathrm{m} / mathrm{s} ) ( theta=60^{circ} operatorname{and} theta^{prime}=30^{circ} ) when patticle mones in peojectile molion it welocity has 2 component nettral and hourculal At ( theta=60^{circ} ), thei zontal nelouty ( =4 cos theta ) At ( theta^{prime}=3 v^{circ} ), thouizontal welocity ( =v cos theta^{prime} ) Duling motion its holizontal component remains constant ( u cos theta=v cos theta ) ( 10 cos 60=v cos 30 ) ( 10 times frac{1}{2}=V times frac{sqrt{3}}{2} ) ( Rightarrow quad V=frac{10}{sqrt{3}} mathrm{m} / mathrm{s} )