An object is dropped from a height of 78.0 m. How long will it take to hit the ground?

3.98978287s

Explanation:

v²=u²+2as

v²=0²+2(9.8)(78)

v²=1528.8m/s

∴v=39.09987212m/s (speed when object hits the ground)

v=u+at

39.09987212=0+9.8t

∴t=3.98978287s

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer

i really dont know but i will try okay.

so i think u would just add all them up and get your answer..