Question

an object thrown vertically upwards reaches a height of 500 metre. What was its initial velocity? How long will the object take to come back to the earth? Assume g=10m/s^2

Answer 1

h= 500m, v= 0, g=10m/s^2

${v}^{2} = {u}^{2} - 2gh$

$0 = {u}^{2} - 2 \times 10 \times 500$

$10000 = {u}^{2}$

$u = 100 \frac{m}{s}$

Now

$v = u - gt$

$0 = 100 - 10t$

$- 100 = - 10t$

$t = 10s$