Question

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} )

# 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

Solution