Question

Two particles of same mass are projected simultaneously with same speed 20m/s from the top of a tower of height 20m one is projected vertically upwards and other projected horizontally.the maximunm height achieved by centre of mass from the ground will be

Answer 1

Increase in vertical distance will be provided by mass projected vertically upwards .

Hence,

At Max height,

            $V_y=0\\U_y = 20m/s\\a_y=-10m/s2$

            ${ V }_{ y }^{ 2 }-{ U }_{ y }^{ 2 }\quad =\quad 2aySy$

            $0-202\quad =\quad 2\times -10\times S_y$

            $S_y=20m$

From Ground,

Maximum height achieved by centre of mass,

= 20 + 20 = 40m

Maximum height can be achieved by climbing a building with maimum height in the city or town.