Answer:
S=ut - 1/2gt"2..{against gravity}.
15t =5t"2..t=0 or 3..t=3s. or 2u/g=3s.
V=0 + gt=10 x 3=30m/s
or
Given,
Initial velocity in upwards direction (u) = -15m/s
Acceleration (a) = 10 m/s2
Distance (s) = 50 m
Final velocity (v) =?
Time taken (t) =?
………..
Final velocity,
2as = v2-u2
2 (10) (50) = (v) 2 – (-15)2
1000 = v2 – 225
1000+225 = v2
1225 = v2
35 = v
Therefore final velocity = 35 m/s
………………..
Time taken,
V=u+at
35=-15+10.t
35+15=10t
50=10t
50/10=t
5=t
Therefore time taken = 5 sec.
