Question

a stone thrown vertically up went 98m and reached the ground.how much time was it in air?

Answer 1

Hmax=u^2/2g
98=u^2/2×10
u^2=1960
u=14×{10}^1/2
T=2u/g
T=2×14×(10)^1/2÷10
T=88.5 seconds