Question

An object is thrown up with a speed of 50 m/s. Its height from the ground after 7 second is

Answer 1

s = ut + 1/2at²
--------------------------
u =50
t =7s
a = - 9.8
s = ?
------------------------------
s = 50(7) + 1/2 (-9.8) (7)²

s = 350 + [- 4.9(49)]

s = 350 -240.1

s=109.9 m
---------------------------------------------------
Its height from the ground after 7 second is 109.9 m

Answer 2

GIVEN , 
                             u = 50 m/s
                              t = 7 s
a due to gravity =  a = -10 m/$s^{2}$
              
               s = ut + $\frac{1}{2}$ a$t^{2}$

               s = 50 * 7 + $\frac{1}{2}$ (-10)$7^{2}$
                  = 350 - 5 * 49
                  = 350 - 245
                  = 105 m