Question

A ball is thrown vertically upwards with a velocity of 10 metre per second . Itreturns to the ground with a velocity of 9 metre per second . If g is 9.8 ,then the maximum height attained by the ball is nearly?

Answer 1

Let, the maximum height attained by the ball is x m & takes t second time from height point to point at ground

Now, applying the formula v = u+gt for the phase of falling

9 = 0 + 9.8.t, or t = 9/9.8

Now, to measure the height from top to ground we can apply the formula

h = ut + (g.t.t)/2, where initial velocity u = 0,

i.e., h = 0 + [(9.8)*(9/9.8)*(9/9.8)]*1/2 = 4.13 m