Question

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

Answer 1

3.98978287s

Step-by-step 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