LE-1920 Pass PH-S8V-21 Megacosm Cog...
Question

# LE-1920 Pass PH-S8V-21 Megacosm Cognitions Pvt. Llu. CHAPTER PRACTICE PROBLEM 1. A particle starts moving with initial velocity 5 m/s. It is accelerating with a constant acceleraton 2 m/s at an angle 120° with the direction of initial velocity. Find the time after which its speed would be 3 times that of the initial speed. A do with a balls B kent at

11th - 12th Class
Physics
Solution
104
4.0 (1 ratings)
Just assume the axes as X-axis along the initial direction of of motion and Y-axis being perpendicular to it. The provided acceleration has its components as ( a_{x}=-1 mathrm{m} / mathrm{s}^{2} ) and ( a_{y}= ) root3 ( mathrm{m} / mathrm{s}^{2} ) thus getting ( mathrm{v}_{mathrm{x}}=(5-mathrm{t}) & mathrm{v}_{mathrm{y}}=mathrm{r} 00 mathrm{t} 3 mathrm{t} ) Now the speed at any time is ( left(v_{x}^{2}+v_{y}^{2}right)^{wedge} .5 ) As per the question demands it should be (root3) 5 Putting the values we get a quadratic equation ( 2 t^{2}-5 t-25=0 ) and hence the feasible value of ( t=5 )