Question

at time T = 0, two balls A and B are projected vertically upwards. the ball A is projected vertically upwards with a speed 2m/s from a point 50 meter about the horizontal ground the ball b is projected vertically upwards from the ground with speed 20m/s. at time t=T seconds, the too balls are at the same height, h metres, about the ground. the balls are modelled as particles moving freely under gravity. find the value of T?​

Answer 1

Answer:

$T=2\frac{7}{9}$ seconds

Step-by-step explanation:

In time T if the height covered by the ball B is h then using the second equation of motion

$h=ut-\frac{1}{2}gt^2$

$h=20T-\frac{1}{2}gT^2$...........(1)

Ball A has travelled h-50 metres in time T

Therefore,

$h-50=2T-\frac{1}{2}gT^2$.........(2)

Subtracting eq (2) from eq (1)

$50=20T-2T$

$\implies 18T=50$

$\implies T=\frac{50}{18}$ seconds

$\implies T=\frac{25}{9}$ seconds

$\implies T=2\frac{7}{9}$ seconds

Hope this helps.